/*
* Copyright 2006 The Closure Compiler Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.google.javascript.jscomp;
import static com.google.javascript.rhino.jstype.JSTypeNative.ARRAY_TYPE;
import static com.google.javascript.rhino.jstype.JSTypeNative.BOOLEAN_TYPE;
import static com.google.javascript.rhino.jstype.JSTypeNative.NULL_TYPE;
import static com.google.javascript.rhino.jstype.JSTypeNative.NUMBER_TYPE;
import static com.google.javascript.rhino.jstype.JSTypeNative.OBJECT_FUNCTION_TYPE;
import static com.google.javascript.rhino.jstype.JSTypeNative.OBJECT_TYPE;
import static com.google.javascript.rhino.jstype.JSTypeNative.REGEXP_TYPE;
import static com.google.javascript.rhino.jstype.JSTypeNative.STRING_TYPE;
import static com.google.javascript.rhino.jstype.JSTypeNative.UNKNOWN_TYPE;
import static com.google.javascript.rhino.jstype.JSTypeNative.VOID_TYPE;
import static java.lang.Integer.MAX_VALUE;
import com.google.common.base.Preconditions;
import com.google.common.collect.ImmutableSet;
import com.google.common.collect.Iterables;
import com.google.javascript.jscomp.CodingConvention.SubclassRelationship;
import com.google.javascript.jscomp.CodingConvention.SubclassType;
import com.google.javascript.jscomp.type.ReverseAbstractInterpreter;
import com.google.javascript.rhino.JSDocInfo;
import com.google.javascript.rhino.JSTypeExpression;
import com.google.javascript.rhino.Node;
import com.google.javascript.rhino.Token;
import com.google.javascript.rhino.jstype.EnumType;
import com.google.javascript.rhino.jstype.FunctionType;
import com.google.javascript.rhino.jstype.JSType;
import com.google.javascript.rhino.jstype.JSType.SubtypingMode;
import com.google.javascript.rhino.jstype.JSTypeNative;
import com.google.javascript.rhino.jstype.JSTypeRegistry;
import com.google.javascript.rhino.jstype.NamedType;
import com.google.javascript.rhino.jstype.ObjectType;
import com.google.javascript.rhino.jstype.Property;
import com.google.javascript.rhino.jstype.TemplateTypeMap;
import com.google.javascript.rhino.jstype.TemplateTypeMapReplacer;
import com.google.javascript.rhino.jstype.TemplatizedType;
import com.google.javascript.rhino.jstype.TernaryValue;
import java.util.HashMap;
import java.util.HashSet;
import java.util.Iterator;
import java.util.LinkedHashMap;
import java.util.List;
import java.util.Map;
import java.util.Objects;
import java.util.Set;
/**
* <p>Checks the types of JS expressions against any declared type
* information.</p>
*
* @author nicksantos@google.com (Nick Santos)
*/
public final class TypeCheck implements NodeTraversal.Callback, CompilerPass {
//
// Internal errors
//
static final DiagnosticType UNEXPECTED_TOKEN = DiagnosticType.error(
"JSC_INTERNAL_ERROR_UNEXPECTED_TOKEN",
"Internal Error: TypeCheck doesn''t know how to handle {0}");
//
// User warnings
//
protected static final String OVERRIDING_PROTOTYPE_WITH_NON_OBJECT =
"overriding prototype with non-object";
static final DiagnosticType DETERMINISTIC_TEST =
DiagnosticType.warning(
"JSC_DETERMINISTIC_TEST",
"condition always evaluates to {2}\n" +
"left : {0}\n" +
"right: {1}");
static final DiagnosticType INEXISTENT_ENUM_ELEMENT =
DiagnosticType.warning(
"JSC_INEXISTENT_ENUM_ELEMENT",
"element {0} does not exist on this enum");
public static final DiagnosticType INEXISTENT_PROPERTY =
DiagnosticType.warning(
"JSC_INEXISTENT_PROPERTY",
"Property {0} never defined on {1}");
// disabled by default. This one only makes sense if you're using
// well-typed externs.
static final DiagnosticType POSSIBLE_INEXISTENT_PROPERTY =
DiagnosticType.disabled(
"JSC_POSSIBLE_INEXISTENT_PROPERTY",
"Property {0} never defined on {1}");
static final DiagnosticType INEXISTENT_PROPERTY_WITH_SUGGESTION =
DiagnosticType.disabled(
"JSC_INEXISTENT_PROPERTY",
"Property {0} never defined on {1}. Did you mean {2}?");
protected static final DiagnosticType NOT_A_CONSTRUCTOR =
DiagnosticType.warning(
"JSC_NOT_A_CONSTRUCTOR",
"cannot instantiate non-constructor");
static final DiagnosticType INSTANTIATE_ABSTRACT_CLASS =
DiagnosticType.warning(
"JSC_INSTANTIATE_ABSTRACT_CLASS",
"cannot instantiate abstract class");
static final DiagnosticType BIT_OPERATION =
DiagnosticType.warning(
"JSC_BAD_TYPE_FOR_BIT_OPERATION",
"operator {0} cannot be applied to {1}");
static final DiagnosticType NOT_CALLABLE =
DiagnosticType.warning(
"JSC_NOT_FUNCTION_TYPE",
"{0} expressions are not callable");
static final DiagnosticType CONSTRUCTOR_NOT_CALLABLE =
DiagnosticType.warning(
"JSC_CONSTRUCTOR_NOT_CALLABLE",
"Constructor {0} should be called with the \"new\" keyword");
static final DiagnosticType ABSTRACT_SUPER_METHOD_NOT_CALLABLE =
DiagnosticType.warning(
"JSC_ABSTRACT_SUPER_METHOD_NOT_CALLABLE", "Abstract super method {0} cannot be called");
static final DiagnosticType FUNCTION_MASKS_VARIABLE =
DiagnosticType.warning("JSC_FUNCTION_MASKS_VARIABLE", "function {0} masks variable (IE bug)");
static final DiagnosticType MULTIPLE_VAR_DEF = DiagnosticType.warning(
"JSC_MULTIPLE_VAR_DEF",
"declaration of multiple variables with shared type information");
static final DiagnosticType ENUM_DUP = DiagnosticType.error("JSC_ENUM_DUP",
"enum element {0} already defined");
static final DiagnosticType INVALID_INTERFACE_MEMBER_DECLARATION =
DiagnosticType.warning(
"JSC_INVALID_INTERFACE_MEMBER_DECLARATION",
"interface members can only be empty property declarations,"
+ " empty functions{0}");
static final DiagnosticType INTERFACE_METHOD_NOT_EMPTY =
DiagnosticType.warning(
"JSC_INTERFACE_METHOD_NOT_EMPTY",
"interface member functions must have an empty body");
static final DiagnosticType CONFLICTING_EXTENDED_TYPE =
DiagnosticType.warning(
"JSC_CONFLICTING_EXTENDED_TYPE",
"{1} cannot extend this type; {0}s can only extend {0}s");
static final DiagnosticType ES5_CLASS_EXTENDING_ES6_CLASS =
DiagnosticType.warning(
"JSC_ES5_CLASS_EXTENDING_ES6_CLASS", "ES5 class {0} cannot extend ES6 class {1}");
static final DiagnosticType INTERFACE_EXTENDS_LOOP =
DiagnosticType.warning("JSC_INTERFACE_EXTENDS_LOOP", "extends loop involving {0}, loop: {1}");
static final DiagnosticType CONFLICTING_IMPLEMENTED_TYPE =
DiagnosticType.warning(
"JSC_CONFLICTING_IMPLEMENTED_TYPE",
"{0} cannot implement this type; " +
"an interface can only extend, but not implement interfaces");
static final DiagnosticType BAD_IMPLEMENTED_TYPE =
DiagnosticType.warning(
"JSC_IMPLEMENTS_NON_INTERFACE",
"can only implement interfaces");
// disabled by default.
static final DiagnosticType HIDDEN_SUPERCLASS_PROPERTY =
DiagnosticType.disabled(
"JSC_HIDDEN_SUPERCLASS_PROPERTY",
"property {0} already defined on superclass {1}; " + "use @override to override it");
// disabled by default.
static final DiagnosticType HIDDEN_INTERFACE_PROPERTY =
DiagnosticType.disabled(
"JSC_HIDDEN_INTERFACE_PROPERTY",
"property {0} already defined on interface {1}; " + "use @override to override it");
static final DiagnosticType HIDDEN_SUPERCLASS_PROPERTY_MISMATCH =
DiagnosticType.warning("JSC_HIDDEN_SUPERCLASS_PROPERTY_MISMATCH",
"mismatch of the {0} property type and the type " +
"of the property it overrides from superclass {1}\n" +
"original: {2}\n" +
"override: {3}");
static final DiagnosticType UNKNOWN_OVERRIDE =
DiagnosticType.warning(
"JSC_UNKNOWN_OVERRIDE",
"property {0} not defined on any superclass of {1}");
static final DiagnosticType INTERFACE_METHOD_OVERRIDE =
DiagnosticType.warning(
"JSC_INTERFACE_METHOD_OVERRIDE",
"property {0} is already defined by the {1} extended interface");
static final DiagnosticType UNKNOWN_EXPR_TYPE =
DiagnosticType.disabled("JSC_UNKNOWN_EXPR_TYPE",
"could not determine the type of this expression");
static final DiagnosticType UNRESOLVED_TYPE =
DiagnosticType.warning("JSC_UNRESOLVED_TYPE",
"could not resolve the name {0} to a type");
static final DiagnosticType WRONG_ARGUMENT_COUNT =
DiagnosticType.warning(
"JSC_WRONG_ARGUMENT_COUNT",
"Function {0}: called with {1} argument(s). " +
"Function requires at least {2} argument(s){3}.");
static final DiagnosticType ILLEGAL_IMPLICIT_CAST =
DiagnosticType.warning(
"JSC_ILLEGAL_IMPLICIT_CAST",
"Illegal annotation on {0}. @implicitCast may only be used in " +
"externs.");
static final DiagnosticType INCOMPATIBLE_EXTENDED_PROPERTY_TYPE =
DiagnosticType.warning(
"JSC_INCOMPATIBLE_EXTENDED_PROPERTY_TYPE",
"Interface {0} has a property {1} with incompatible types in " +
"its super interfaces {2} and {3}");
static final DiagnosticType EXPECTED_THIS_TYPE =
DiagnosticType.warning(
"JSC_EXPECTED_THIS_TYPE",
"\"{0}\" must be called with a \"this\" type");
static final DiagnosticType IN_USED_WITH_STRUCT =
DiagnosticType.warning("JSC_IN_USED_WITH_STRUCT",
"Cannot use the IN operator with structs");
static final DiagnosticType ILLEGAL_PROPERTY_CREATION =
DiagnosticType.warning("JSC_ILLEGAL_PROPERTY_CREATION",
"Cannot add a property to a struct instance after it is constructed."
+ " (If you already declared the property, make sure to give it a type.)");
static final DiagnosticType ILLEGAL_OBJLIT_KEY =
DiagnosticType.warning(
"JSC_ILLEGAL_OBJLIT_KEY",
"Illegal key, the object literal is a {0}");
static final DiagnosticType NON_STRINGIFIABLE_OBJECT_KEY =
DiagnosticType.warning(
"JSC_NON_STRINGIFIABLE_OBJECT_KEY",
"Object type \"{0}\" contains non-stringifiable key and it may lead to an "
+ "error. Please use ES6 Map instead or implement your own Map structure.");
static final DiagnosticType ABSTRACT_METHOD_IN_CONCRETE_CLASS =
DiagnosticType.warning(
"JSC_ABSTRACT_METHOD_IN_CONCRETE_CLASS",
"Abstract methods can only appear in abstract classes. Please declare the class as "
+ "@abstract");
// If a diagnostic is disabled by default, do not add it in this list
// TODO(dimvar): Either INEXISTENT_PROPERTY shouldn't be here, or we should
// change DiagnosticGroups.setWarningLevel to not accidentally enable it.
static final DiagnosticGroup ALL_DIAGNOSTICS =
new DiagnosticGroup(
DETERMINISTIC_TEST,
INEXISTENT_ENUM_ELEMENT,
INEXISTENT_PROPERTY,
POSSIBLE_INEXISTENT_PROPERTY,
INEXISTENT_PROPERTY_WITH_SUGGESTION,
NOT_A_CONSTRUCTOR,
INSTANTIATE_ABSTRACT_CLASS,
BIT_OPERATION,
NOT_CALLABLE,
CONSTRUCTOR_NOT_CALLABLE,
FUNCTION_MASKS_VARIABLE,
MULTIPLE_VAR_DEF,
ENUM_DUP,
INVALID_INTERFACE_MEMBER_DECLARATION,
INTERFACE_METHOD_NOT_EMPTY,
CONFLICTING_EXTENDED_TYPE,
CONFLICTING_IMPLEMENTED_TYPE,
BAD_IMPLEMENTED_TYPE,
HIDDEN_SUPERCLASS_PROPERTY_MISMATCH,
UNKNOWN_OVERRIDE,
INTERFACE_METHOD_OVERRIDE,
UNRESOLVED_TYPE,
WRONG_ARGUMENT_COUNT,
ILLEGAL_IMPLICIT_CAST,
INCOMPATIBLE_EXTENDED_PROPERTY_TYPE,
EXPECTED_THIS_TYPE,
IN_USED_WITH_STRUCT,
ILLEGAL_PROPERTY_CREATION,
ILLEGAL_OBJLIT_KEY,
NON_STRINGIFIABLE_OBJECT_KEY,
ABSTRACT_METHOD_IN_CONCRETE_CLASS,
ABSTRACT_SUPER_METHOD_NOT_CALLABLE,
ES5_CLASS_EXTENDING_ES6_CLASS,
RhinoErrorReporter.TYPE_PARSE_ERROR,
RhinoErrorReporter.UNRECOGNIZED_TYPE_ERROR,
TypedScopeCreator.UNKNOWN_LENDS,
TypedScopeCreator.LENDS_ON_NON_OBJECT,
TypedScopeCreator.CTOR_INITIALIZER,
TypedScopeCreator.IFACE_INITIALIZER,
FunctionTypeBuilder.THIS_TYPE_NON_OBJECT);
private final AbstractCompiler compiler;
private final TypeValidator validator;
private final ReverseAbstractInterpreter reverseInterpreter;
private final JSTypeRegistry typeRegistry;
private TypedScope topScope;
private MemoizedScopeCreator scopeCreator;
private final boolean reportUnknownTypes;
private SubtypingMode subtypingMode = SubtypingMode.NORMAL;
// This may be expensive, so don't emit these warnings if they're
// explicitly turned off.
private boolean reportMissingProperties = true;
private InferJSDocInfo inferJSDocInfo = null;
// These fields are used to calculate the percentage of expressions typed.
private int typedCount = 0;
private int nullCount = 0;
private int unknownCount = 0;
private boolean inExterns;
private static final class SuggestionPair {
private final String suggestion;
final int distance;
private SuggestionPair(String suggestion, int distance) {
this.suggestion = suggestion;
this.distance = distance;
}
}
public TypeCheck(
AbstractCompiler compiler,
ReverseAbstractInterpreter reverseInterpreter,
JSTypeRegistry typeRegistry,
TypedScope topScope,
MemoizedScopeCreator scopeCreator) {
this.compiler = compiler;
this.validator = compiler.getTypeValidator();
this.reverseInterpreter = reverseInterpreter;
this.typeRegistry = typeRegistry;
this.topScope = topScope;
this.scopeCreator = scopeCreator;
this.reportUnknownTypes = ((Compiler) compiler).getOptions().enables(
DiagnosticGroups.REPORT_UNKNOWN_TYPES);
this.inferJSDocInfo = new InferJSDocInfo(compiler);
}
public TypeCheck(AbstractCompiler compiler,
ReverseAbstractInterpreter reverseInterpreter,
JSTypeRegistry typeRegistry) {
this(compiler, reverseInterpreter, typeRegistry, null, null);
}
/** Turn on the missing property check. Returns this for easy chaining. */
TypeCheck reportMissingProperties(boolean report) {
reportMissingProperties = report;
return this;
}
/**
* Main entry point for this phase of processing. This follows the pattern for
* JSCompiler phases.
*
* @param externsRoot The root of the externs parse tree.
* @param jsRoot The root of the input parse tree to be checked.
*/
@Override
public void process(Node externsRoot, Node jsRoot) {
Preconditions.checkNotNull(scopeCreator);
Preconditions.checkNotNull(topScope);
Node externsAndJs = jsRoot.getParent();
Preconditions.checkState(externsAndJs != null);
Preconditions.checkState(
externsRoot == null || externsAndJs.hasChild(externsRoot));
if (externsRoot != null) {
check(externsRoot, true);
}
check(jsRoot, false);
}
/** Main entry point of this phase for testing code. */
public TypedScope processForTesting(Node externsRoot, Node jsRoot) {
Preconditions.checkState(scopeCreator == null);
Preconditions.checkState(topScope == null);
Preconditions.checkState(jsRoot.getParent() != null);
Node externsAndJsRoot = jsRoot.getParent();
scopeCreator = new MemoizedScopeCreator(new TypedScopeCreator(compiler));
topScope = scopeCreator.createScope(externsAndJsRoot, null);
TypeInferencePass inference = new TypeInferencePass(compiler,
reverseInterpreter, topScope, scopeCreator);
inference.process(externsRoot, jsRoot);
process(externsRoot, jsRoot);
return topScope;
}
void check(Node node, boolean externs) {
Preconditions.checkNotNull(node);
NodeTraversal t = new NodeTraversal(compiler, this, scopeCreator);
inExterns = externs;
t.traverseWithScope(node, topScope);
if (externs) {
inferJSDocInfo.process(node, null);
} else {
inferJSDocInfo.process(null, node);
}
}
private void report(NodeTraversal t, Node n, DiagnosticType diagnosticType,
String... arguments) {
t.report(n, diagnosticType, arguments);
}
@Override
public boolean shouldTraverse(NodeTraversal t, Node n, Node parent) {
if (n.isScript()) {
String filename = n.getSourceFileName();
if (filename != null && filename.endsWith(".java.js")) {
this.subtypingMode = SubtypingMode.IGNORE_NULL_UNDEFINED;
} else {
this.subtypingMode = SubtypingMode.NORMAL;
}
this.validator.setSubtypingMode(this.subtypingMode);
}
switch (n.getToken()) {
case FUNCTION:
// normal type checking
final TypedScope outerScope = t.getTypedScope();
final String functionPrivateName = n.getFirstChild().getString();
if (functionPrivateName != null && functionPrivateName.length() > 0 &&
outerScope.isDeclared(functionPrivateName, false) &&
// Ideally, we would want to check whether the type in the scope
// differs from the type being defined, but then the extern
// redeclarations of built-in types generates spurious warnings.
!(outerScope.getVar(
functionPrivateName).getType() instanceof FunctionType)) {
report(t, n, FUNCTION_MASKS_VARIABLE, functionPrivateName);
}
// TODO(user): Only traverse the function's body. The function's
// name and arguments are traversed by the scope creator, and ideally
// should not be traversed by the type checker.
break;
default:
break;
}
return true;
}
/**
* This is the meat of the type checking. It is basically one big switch,
* with each case representing one type of parse tree node. The individual
* cases are usually pretty straightforward.
*
* @param t The node traversal object that supplies context, such as the
* scope chain to use in name lookups as well as error reporting.
* @param n The node being visited.
* @param parent The parent of the node n.
*/
@Override
public void visit(NodeTraversal t, Node n, Node parent) {
JSType childType;
JSType leftType;
JSType rightType;
Node left;
Node right;
// To be explicitly set to false if the node is not typeable.
boolean typeable = true;
switch (n.getToken()) {
case CAST:
Node expr = n.getFirstChild();
JSType exprType = getJSType(expr);
JSType castType = getJSType(n);
// TODO(johnlenz): determine if we can limit object literals in some
// way.
if (!expr.isObjectLit()) {
validator.expectCanCast(t, n, castType, exprType);
}
ensureTyped(t, n, castType);
expr.putProp(Node.TYPE_BEFORE_CAST, exprType);
if (castType.restrictByNotNullOrUndefined().isSubtype(exprType)
|| expr.isObjectLit()) {
expr.setJSType(castType);
}
break;
case NAME:
typeable = visitName(t, n, parent);
break;
case COMMA:
ensureTyped(t, n, getJSType(n.getLastChild()));
break;
case THIS:
ensureTyped(t, n, t.getTypedScope().getTypeOfThis());
break;
case SUPER:
ensureTyped(t, n);
break;
case NULL:
ensureTyped(t, n, NULL_TYPE);
break;
case NUMBER:
ensureTyped(t, n, NUMBER_TYPE);
break;
case GETTER_DEF:
case SETTER_DEF:
// Object literal keys are handled with OBJECTLIT
break;
case ARRAYLIT:
ensureTyped(t, n, ARRAY_TYPE);
break;
case REGEXP:
ensureTyped(t, n, REGEXP_TYPE);
break;
case GETPROP:
visitGetProp(t, n, parent);
typeable = !(parent.isAssign() && parent.getFirstChild() == n);
break;
case GETELEM:
visitGetElem(t, n);
// The type of GETELEM is always unknown, so no point counting that.
// If that unknown leaks elsewhere (say by an assignment to another
// variable), then it will be counted.
typeable = false;
break;
case VAR:
visitVar(t, n);
typeable = false;
break;
case NEW:
visitNew(t, n);
break;
case CALL:
visitCall(t, n);
typeable = !parent.isExprResult();
break;
case RETURN:
visitReturn(t, n);
typeable = false;
break;
case DEC:
case INC:
left = n.getFirstChild();
checkPropCreation(t, left);
validator.expectNumber(t, left, getJSType(left), "increment/decrement");
ensureTyped(t, n, NUMBER_TYPE);
break;
case VOID:
ensureTyped(t, n, VOID_TYPE);
break;
case STRING:
case TYPEOF:
ensureTyped(t, n, STRING_TYPE);
break;
case BITNOT:
childType = getJSType(n.getFirstChild());
if (!childType.matchesInt32Context()) {
report(t, n, BIT_OPERATION, NodeUtil.opToStr(n.getToken()), childType.toString());
}
ensureTyped(t, n, NUMBER_TYPE);
break;
case POS:
case NEG:
left = n.getFirstChild();
validator.expectNumber(t, left, getJSType(left), "sign operator");
ensureTyped(t, n, NUMBER_TYPE);
break;
case EQ:
case NE:
case SHEQ:
case SHNE:
{
left = n.getFirstChild();
right = n.getLastChild();
if (left.isTypeOf()) {
if (right.isString()) {
checkTypeofString(t, right, right.getString());
}
} else if (right.isTypeOf() && left.isString()) {
checkTypeofString(t, left, left.getString());
}
leftType = getJSType(left);
rightType = getJSType(right);
// We do not want to warn about explicit comparisons to VOID. People
// often do this if they think their type annotations screwed up.
//
// We do want to warn about cases where people compare things like
// (Array|null) == (Function|null)
// because it probably means they screwed up.
//
// This heuristic here is not perfect, but should catch cases we
// care about without too many false negatives.
JSType leftTypeRestricted = leftType.restrictByNotNullOrUndefined();
JSType rightTypeRestricted = rightType.restrictByNotNullOrUndefined();
TernaryValue result = TernaryValue.UNKNOWN;
if (n.getToken() == Token.EQ || n.isNE()) {
result = leftTypeRestricted.testForEquality(rightTypeRestricted);
if (n.isNE()) {
result = result.not();
}
} else {
// SHEQ or SHNE
if (!leftTypeRestricted.canTestForShallowEqualityWith(rightTypeRestricted)) {
result = n.getToken() == Token.SHEQ ? TernaryValue.FALSE : TernaryValue.TRUE;
}
}
if (result != TernaryValue.UNKNOWN) {
report(
t,
n,
DETERMINISTIC_TEST,
leftType.toString(),
rightType.toString(),
result.toString());
}
ensureTyped(t, n, BOOLEAN_TYPE);
break;
}
case LT:
case LE:
case GT:
case GE:
leftType = getJSType(n.getFirstChild());
rightType = getJSType(n.getLastChild());
if (rightType.isNumber()) {
validator.expectNumber(t, n, leftType, "left side of numeric comparison");
} else if (leftType.isNumber()) {
validator.expectNumber(t, n, rightType, "right side of numeric comparison");
} else if (leftType.matchesNumberContext() && rightType.matchesNumberContext()) {
// OK.
} else {
// Whether the comparison is numeric will be determined at runtime
// each time the expression is evaluated. Regardless, both operands
// should match a string context.
String message = "left side of comparison";
validator.expectString(t, n, leftType, message);
validator.expectNotNullOrUndefined(t, n, leftType, message, getNativeType(STRING_TYPE));
message = "right side of comparison";
validator.expectString(t, n, rightType, message);
validator.expectNotNullOrUndefined(t, n, rightType, message, getNativeType(STRING_TYPE));
}
ensureTyped(t, n, BOOLEAN_TYPE);
break;
case IN:
left = n.getFirstChild();
right = n.getLastChild();
rightType = getJSType(right);
validator.expectString(t, left, getJSType(left), "left side of 'in'");
validator.expectObject(t, n, rightType, "'in' requires an object");
if (rightType.isStruct()) {
report(t, right, IN_USED_WITH_STRUCT);
}
ensureTyped(t, n, BOOLEAN_TYPE);
break;
case INSTANCEOF:
left = n.getFirstChild();
right = n.getLastChild();
rightType = getJSType(right).restrictByNotNullOrUndefined();
validator.expectAnyObject(
t, left, getJSType(left), "deterministic instanceof yields false");
validator.expectActualObject(t, right, rightType, "instanceof requires an object");
ensureTyped(t, n, BOOLEAN_TYPE);
break;
case ASSIGN:
visitAssign(t, n);
typeable = false;
break;
case ASSIGN_LSH:
case ASSIGN_RSH:
case ASSIGN_URSH:
case ASSIGN_DIV:
case ASSIGN_MOD:
case ASSIGN_BITOR:
case ASSIGN_BITXOR:
case ASSIGN_BITAND:
case ASSIGN_SUB:
case ASSIGN_ADD:
case ASSIGN_MUL:
checkPropCreation(t, n.getFirstChild());
// fall through
case LSH:
case RSH:
case URSH:
case DIV:
case MOD:
case BITOR:
case BITXOR:
case BITAND:
case SUB:
case ADD:
case MUL:
visitBinaryOperator(n.getToken(), t, n);
break;
case TRUE:
case FALSE:
case NOT:
case DELPROP:
ensureTyped(t, n, BOOLEAN_TYPE);
break;
case CASE:
JSType switchType = getJSType(parent.getFirstChild());
JSType caseType = getJSType(n.getFirstChild());
validator.expectSwitchMatchesCase(t, n, switchType, caseType);
typeable = false;
break;
case WITH: {
Node child = n.getFirstChild();
childType = getJSType(child);
validator.expectObject(t, child, childType, "with requires an object");
typeable = false;
break;
}
case MEMBER_FUNCTION_DEF:
ensureTyped(t, n, getJSType(n.getFirstChild()));
break;
case FUNCTION:
visitFunction(t, n);
break;
// These nodes have no interesting type behavior.
// These nodes require data flow analysis.
case PARAM_LIST:
case STRING_KEY:
case LABEL:
case LABEL_NAME:
case SWITCH:
case BREAK:
case CATCH:
case TRY:
case SCRIPT:
case EXPR_RESULT:
case BLOCK:
case ROOT:
case EMPTY:
case DEFAULT_CASE:
case CONTINUE:
case DEBUGGER:
case THROW:
case DO:
case IF:
case WHILE:
case FOR:
typeable = false;
break;
case FOR_IN:
Node obj = n.getSecondChild();
if (getJSType(obj).isStruct()) {
report(t, obj, IN_USED_WITH_STRUCT);
}
typeable = false;
break;
// These nodes are typed during the type inference.
case AND:
case HOOK:
case OBJECTLIT:
case OR:
if (n.getJSType() != null) { // If we didn't run type inference.
ensureTyped(t, n);
} else {
// If this is an enum, then give that type to the objectlit as well.
if ((n.isObjectLit()) && (parent.getJSType() instanceof EnumType)) {
ensureTyped(t, n, parent.getJSType());
} else {
ensureTyped(t, n);
}
}
if (n.isObjectLit()) {
JSType typ = getJSType(n);
for (Node key : n.children()) {
visitObjLitKey(t, key, n, typ);
}
}
break;
default:
report(t, n, UNEXPECTED_TOKEN, n.getToken().toString());
ensureTyped(t, n);
break;
}
// Don't count externs since the user's code may not even use that part.
typeable = typeable && !inExterns;
if (typeable) {
doPercentTypedAccounting(t, n);
}
checkJsdocInfoContainsObjectWithBadKey(t, n);
}
private void checkTypeofString(NodeTraversal t, Node n, String s) {
if (!(s.equals("number") || s.equals("string") || s.equals("boolean") ||
s.equals("undefined") || s.equals("function") ||
s.equals("object") || s.equals("unknown"))) {
validator.expectValidTypeofName(t, n, s);
}
}
/**
* Counts the given node in the typed statistics.
* @param n a node that should be typed
*/
private void doPercentTypedAccounting(NodeTraversal t, Node n) {
JSType type = n.getJSType();
if (type == null) {
nullCount++;
} else if (type.isUnknownType()) {
if (reportUnknownTypes) {
compiler.report(t.makeError(n, UNKNOWN_EXPR_TYPE));
}
unknownCount++;
} else {
typedCount++;
}
}
/**
* Visits an assignment <code>lvalue = rvalue</code>. If the
* <code>lvalue</code> is a prototype modification, we change the schema
* of the object type it is referring to.
* @param t the traversal
* @param assign the assign node
* (<code>assign.isAssign()</code> is an implicit invariant)
*/
private void visitAssign(NodeTraversal t, Node assign) {
JSDocInfo info = assign.getJSDocInfo();
Node lvalue = assign.getFirstChild();
Node rvalue = assign.getLastChild();
// Check property sets to 'object.property' when 'object' is known.
if (lvalue.isGetProp()) {
Node object = lvalue.getFirstChild();
JSType objectJsType = getJSType(object);
Node property = lvalue.getLastChild();
String pname = property.getString();
// the first name in this getprop refers to an interface
// we perform checks in addition to the ones below
if (object.isGetProp()) {
JSType jsType = getJSType(object.getFirstChild());
if (jsType.isInterface() &&
object.getLastChild().getString().equals("prototype")) {
visitInterfaceGetprop(t, assign, object, pname, lvalue, rvalue);
}
}
checkEnumAlias(t, info, rvalue);
checkPropCreation(t, lvalue);
// Prototype assignments are special, because they actually affect
// the definition of a class. These are mostly validated
// during TypedScopeCreator, and we only look for the "dumb" cases here.
// object.prototype = ...;
if (pname.equals("prototype")) {
if (objectJsType != null && objectJsType.isFunctionType()) {
FunctionType functionType = objectJsType.toMaybeFunctionType();
if (functionType.isConstructor()) {
JSType rvalueType = rvalue.getJSType();
validator.expectObject(t, rvalue, rvalueType,
OVERRIDING_PROTOTYPE_WITH_NON_OBJECT);
return;
}
}
}
// The generic checks for 'object.property' when 'object' is known,
// and 'property' is declared on it.
// object.property = ...;
ObjectType type = ObjectType.cast(
objectJsType.restrictByNotNullOrUndefined());
if (type != null) {
if (type.hasProperty(pname) &&
!type.isPropertyTypeInferred(pname)) {
JSType expectedType = type.getPropertyType(pname);
if (!expectedType.isUnknownType()) {
if (!propertyIsImplicitCast(type, pname)) {
validator.expectCanAssignToPropertyOf(
t, assign, getJSType(rvalue),
expectedType, object, pname);
checkPropertyInheritanceOnGetpropAssign(
t, assign, object, pname, info, expectedType);
}
return;
}
}
}
// If we couldn't get the property type with normal object property
// lookups, then check inheritance anyway with the unknown type.
checkPropertyInheritanceOnGetpropAssign(
t, assign, object, pname, info, getNativeType(UNKNOWN_TYPE));
}
// Check qualified name sets to 'object' and 'object.property'.
// This can sometimes handle cases when the type of 'object' is not known.
// e.g.,
// var obj = createUnknownType();
// /** @type {number} */ obj.foo = true;
JSType leftType = getJSType(lvalue);
if (lvalue.isQualifiedName()) {
// variable with inferred type case
TypedVar var = t.getTypedScope().getVar(lvalue.getQualifiedName());
if (var != null) {
if (var.isTypeInferred()) {
return;
}
if (NodeUtil.getRootOfQualifiedName(lvalue).isThis() &&
t.getTypedScope() != var.getScope()) {
// Don't look at "this.foo" variables from other scopes.
return;
}
if (var.getType() != null) {
leftType = var.getType();
}
}
}
// Fall through case for arbitrary LHS and arbitrary RHS.
Node rightChild = assign.getLastChild();
JSType rightType = getJSType(rightChild);
if (validator.expectCanAssignTo(
t, assign, rightType, leftType, "assignment")) {
ensureTyped(t, assign, rightType);
} else {
ensureTyped(t, assign);
}
}
private void checkPropCreation(NodeTraversal t, Node lvalue) {
if (lvalue.isGetProp()) {
JSType objType = getJSType(lvalue.getFirstChild());
Node prop = lvalue.getLastChild();
if (objType.isStruct() && !objType.hasProperty(prop.getString())) {
report(t, prop, ILLEGAL_PROPERTY_CREATION);
}
}
}
private void checkPropertyInheritanceOnGetpropAssign(
NodeTraversal t, Node assign, Node object, String property,
JSDocInfo info, JSType propertyType) {
// Inheritance checks for prototype properties.
//
// TODO(nicksantos): This isn't the right place to do this check. We
// really want to do this when we're looking at the constructor.
// We'd find all its properties and make sure they followed inheritance
// rules, like we currently do for @implements to make sure
// all the methods are implemented.
//
// As-is, this misses many other ways to override a property.
//
// object.prototype.property = ...;
if (object.isGetProp()) {
Node object2 = object.getFirstChild();
String property2 = NodeUtil.getStringValue(object.getLastChild());
if ("prototype".equals(property2)) {
JSType jsType = getJSType(object2);
if (jsType.isFunctionType()) {
FunctionType functionType = jsType.toMaybeFunctionType();
if (functionType.isConstructor() || functionType.isInterface()) {
checkDeclaredPropertyInheritance(
t, assign, functionType, property, info, propertyType);
checkAbstractMethodInConcreteClass(t, assign, functionType, info);
}
}
}
}
}
private void checkPropertyInheritanceOnPrototypeLitKey(
NodeTraversal t, Node key, String propertyName, ObjectType type) {
// Inheritance checks for prototype objlit properties.
//
// TODO(nicksantos): This isn't the right place to do this check. We
// really want to do this when we're looking at the constructor.
// We'd find all its properties and make sure they followed inheritance
// rules, like we currently do for @implements to make sure
// all the methods are implemented.
//
// As-is, this misses many other ways to override a property.
//
// object.prototype = { key: function() {} };
FunctionType ctorType = type.getOwnerFunction();
if (ctorType == null || (!ctorType.isConstructor() && !ctorType.isInterface())) {
return;
}
JSType propertyType = type.getPropertyType(propertyName);
checkDeclaredPropertyInheritance(
t, key.getFirstChild(), ctorType, propertyName,
key.getJSDocInfo(), propertyType);
}
/**
* Visits an object literal field definition <code>key : value</code>.
*
* If the <code>lvalue</code> is a prototype modification, we change the
* schema of the object type it is referring to.
*
* @param t the traversal
* @param key the assign node
*/
private void visitObjLitKey(
NodeTraversal t, Node key, Node objlit, JSType litType) {
// Do not validate object lit value types in externs. We don't really care,
// and it makes it easier to generate externs.
if (objlit.isFromExterns()) {
ensureTyped(t, key);
return;
}
// Structs must have unquoted keys and dicts must have quoted keys
if (litType.isStruct() && key.isQuotedString()) {
report(t, key, ILLEGAL_OBJLIT_KEY, "struct");
} else if (litType.isDict() && !key.isQuotedString()) {
report(t, key, ILLEGAL_OBJLIT_KEY, "dict");
}
// TODO(johnlenz): Validate get and set function declarations are valid
// as is the functions can have "extraneous" bits.
// For getter and setter property definitions the
// r-value type != the property type.
Node rvalue = key.getFirstChild();
JSType rightType = getObjectLitKeyTypeFromValueType(key, getJSType(rvalue));
if (rightType == null) {
rightType = getNativeType(UNKNOWN_TYPE);
}
Node owner = objlit;
// Validate value is assignable to the key type.
JSType keyType = getJSType(key);
JSType allowedValueType = keyType;
if (allowedValueType.isEnumElementType()) {
allowedValueType =
allowedValueType.toMaybeEnumElementType().getPrimitiveType();
}
boolean valid = validator.expectCanAssignToPropertyOf(t, key,
rightType, allowedValueType,
owner, NodeUtil.getObjectLitKeyName(key));
if (valid) {
ensureTyped(t, key, rightType);
} else {
ensureTyped(t, key);
}
// Validate that the key type is assignable to the object property type.
// This is necessary as the objlit may have been cast to a non-literal
// object type.
// TODO(johnlenz): consider introducing a CAST node to the AST (or
// perhaps a parentheses node).
JSType objlitType = getJSType(objlit);
ObjectType type = ObjectType.cast(
objlitType.restrictByNotNullOrUndefined());
if (type != null) {
String property = NodeUtil.getObjectLitKeyName(key);
checkPropertyInheritanceOnPrototypeLitKey(t, key, property, type);
if (type.hasProperty(property) &&
!type.isPropertyTypeInferred(property) &&
!propertyIsImplicitCast(type, property)) {
validator.expectCanAssignToPropertyOf(
t, key, keyType,
type.getPropertyType(property), owner, property);
}
return;
}
}
/**
* Returns true if any type in the chain has an implicitCast annotation for
* the given property.
*/
private static boolean propertyIsImplicitCast(ObjectType type, String prop) {
for (; type != null; type = type.getImplicitPrototype()) {
JSDocInfo docInfo = type.getOwnPropertyJSDocInfo(prop);
if (docInfo != null && docInfo.isImplicitCast()) {
return true;
}
}
return false;
}
/**
* Given a constructor type and a property name, check that the property has
* the JSDoc annotation @override iff the property is declared on a
* superclass. Several checks regarding inheritance correctness are also
* performed.
*/
private void checkDeclaredPropertyInheritance(
NodeTraversal t, Node n, FunctionType ctorType, String propertyName,
JSDocInfo info, JSType propertyType) {
// If the supertype doesn't resolve correctly, we've warned about this
// already.
if (hasUnknownOrEmptySupertype(ctorType)) {
return;
}
FunctionType superClass = ctorType.getSuperClassConstructor();
boolean superClassHasProperty = superClass != null &&
superClass.getInstanceType().hasProperty(propertyName);
boolean superClassHasDeclaredProperty = superClass != null &&
superClass.getInstanceType().isPropertyTypeDeclared(propertyName);
// For interface
boolean superInterfaceHasProperty = false;
boolean superInterfaceHasDeclaredProperty = false;
if (ctorType.isInterface()) {
for (ObjectType interfaceType : ctorType.getExtendedInterfaces()) {
superInterfaceHasProperty =
superInterfaceHasProperty ||
interfaceType.hasProperty(propertyName);
superInterfaceHasDeclaredProperty =
superInterfaceHasDeclaredProperty ||
interfaceType.isPropertyTypeDeclared(propertyName);
}
}
boolean declaredOverride = info != null && info.isOverride();
boolean foundInterfaceProperty = false;
if (ctorType.isConstructor()) {
for (JSType implementedInterface :
ctorType.getAllImplementedInterfaces()) {
if (implementedInterface.isUnknownType() ||
implementedInterface.isEmptyType()) {
continue;
}
FunctionType interfaceType =
implementedInterface.toObjectType().getConstructor();
Preconditions.checkNotNull(interfaceType);
boolean interfaceHasProperty =
interfaceType.getPrototype().hasProperty(propertyName);
foundInterfaceProperty = foundInterfaceProperty ||
interfaceHasProperty;
if (!declaredOverride && interfaceHasProperty && !"__proto__".equals(propertyName)) {
// @override not present, but the property does override an interface
// property
compiler.report(
t.makeError(
n,
HIDDEN_INTERFACE_PROPERTY,
propertyName,
interfaceType.getTopMostDefiningType(propertyName).toString()));
}
}
}
if (!declaredOverride
&& !superClassHasProperty
&& !superInterfaceHasProperty) {
// nothing to do here, it's just a plain new property
return;
}
ObjectType topInstanceType = superClassHasDeclaredProperty ?
superClass.getTopMostDefiningType(propertyName) : null;
boolean declaredLocally =
ctorType.isConstructor() &&
(ctorType.getPrototype().hasOwnProperty(propertyName) ||
ctorType.getInstanceType().hasOwnProperty(propertyName));
if (!declaredOverride
&& superClassHasDeclaredProperty
&& declaredLocally
&& !"__proto__".equals(propertyName)) {
// @override not present, but the property does override a superclass
// property
compiler.report(
t.makeError(n, HIDDEN_SUPERCLASS_PROPERTY, propertyName, topInstanceType.toString()));
}
// @override is present and we have to check that it is ok
if (superClassHasDeclaredProperty) {
// there is a superclass implementation
JSType superClassPropType =
superClass.getInstanceType().getPropertyType(propertyName);
TemplateTypeMap ctorTypeMap =
ctorType.getTypeOfThis().getTemplateTypeMap();
if (!ctorTypeMap.isEmpty()) {
superClassPropType = superClassPropType.visit(
new TemplateTypeMapReplacer(typeRegistry, ctorTypeMap));
}
if (!propertyType.isSubtype(superClassPropType, this.subtypingMode)) {
compiler.report(
t.makeError(n, HIDDEN_SUPERCLASS_PROPERTY_MISMATCH,
propertyName, topInstanceType.toString(),
superClassPropType.toString(), propertyType.toString()));
}
} else if (superInterfaceHasDeclaredProperty) {
// there is an super interface property
for (ObjectType interfaceType : ctorType.getExtendedInterfaces()) {
if (interfaceType.hasProperty(propertyName)) {
JSType superPropertyType =
interfaceType.getPropertyType(propertyName);
if (!propertyType.isSubtype(superPropertyType, this.subtypingMode)) {
topInstanceType = interfaceType.getConstructor().
getTopMostDefiningType(propertyName);
compiler.report(
t.makeError(n, HIDDEN_SUPERCLASS_PROPERTY_MISMATCH,
propertyName, topInstanceType.toString(),
superPropertyType.toString(),
propertyType.toString()));
}
}
}
} else if (!foundInterfaceProperty
&& !superClassHasProperty
&& !superInterfaceHasProperty) {
// there is no superclass nor interface implementation
compiler.report(
t.makeError(n, UNKNOWN_OVERRIDE,
propertyName, ctorType.getInstanceType().toString()));
}
}
private void checkAbstractMethodInConcreteClass(
NodeTraversal t, Node n, FunctionType ctorType, JSDocInfo info) {
if (info == null || !info.isAbstract()) {
return;
}
if (ctorType.isConstructor() && !ctorType.isAbstract()) {
report(t, n, ABSTRACT_METHOD_IN_CONCRETE_CLASS);
}
}
/**
* Given a constructor or an interface type, find out whether the unknown
* type is a supertype of the current type.
*/
private static boolean hasUnknownOrEmptySupertype(FunctionType ctor) {
Preconditions.checkArgument(ctor.isConstructor() || ctor.isInterface());
Preconditions.checkArgument(!ctor.isUnknownType());
// The type system should notice inheritance cycles on its own
// and break the cycle.
while (true) {
ObjectType maybeSuperInstanceType =
ctor.getPrototype().getImplicitPrototype();
if (maybeSuperInstanceType == null) {
return false;
}
if (maybeSuperInstanceType.isUnknownType() ||
maybeSuperInstanceType.isEmptyType()) {
return true;
}
ctor = maybeSuperInstanceType.getConstructor();
if (ctor == null) {
return false;
}
Preconditions.checkState(ctor.isConstructor() || ctor.isInterface());
}
}
/**
* @param key A OBJECTLIT key node.
* @return The type expected when using the key.
*/
static JSType getObjectLitKeyTypeFromValueType(Node key, JSType valueType) {
if (valueType != null) {
switch (key.getToken()) {
case GETTER_DEF:
// GET must always return a function type.
if (valueType.isFunctionType()) {
FunctionType fntype = valueType.toMaybeFunctionType();
valueType = fntype.getReturnType();
} else {
return null;
}
break;
case SETTER_DEF:
if (valueType.isFunctionType()) {
// SET must always return a function type.
FunctionType fntype = valueType.toMaybeFunctionType();
Node param = fntype.getParametersNode().getFirstChild();
// SET function must always have one parameter.
valueType = param.getJSType();
} else {
return null;
}
break;
default:
break;
}
}
return valueType;
}
/**
* Visits an ASSIGN node for cases such as
* <pre>
* interface.property2.property = ...;
* </pre>
*/
private void visitInterfaceGetprop(NodeTraversal t, Node assign, Node object,
String property, Node lvalue, Node rvalue) {
JSType rvalueType = getJSType(rvalue);
// Only 2 values are allowed for methods:
// goog.abstractMethod
// function () {};
// or for properties, no assignment such as:
// InterfaceFoo.prototype.foobar;
String abstractMethodName =
compiler.getCodingConvention().getAbstractMethodName();
if (!rvalueType.isFunctionType()) {
// This is bad i18n style but we don't localize our compiler errors.
String abstractMethodMessage = (abstractMethodName != null)
? ", or " + abstractMethodName
: "";
compiler.report(
t.makeError(object, INVALID_INTERFACE_MEMBER_DECLARATION,
abstractMethodMessage));
}
if (assign.getLastChild().isFunction()
&& !NodeUtil.isEmptyBlock(assign.getLastChild().getLastChild())) {
compiler.report(
t.makeError(object, INTERFACE_METHOD_NOT_EMPTY,
abstractMethodName));
}
}
/**
* Visits a NAME node.
*
* @param t The node traversal object that supplies context, such as the
* scope chain to use in name lookups as well as error reporting.
* @param n The node being visited.
* @param parent The parent of the node n.
* @return whether the node is typeable or not
*/
boolean visitName(NodeTraversal t, Node n, Node parent) {
// At this stage, we need to determine whether this is a leaf
// node in an expression (which therefore needs to have a type
// assigned for it) versus some other decorative node that we
// can safely ignore. Function names, arguments (children of PARAM_LIST nodes) and
// variable declarations are ignored.
// TODO(user): remove this short-circuiting in favor of a
// pre order traversal of the FUNCTION, CATCH, PARAM_LIST and VAR nodes.
Token parentNodeType = parent.getToken();
if (parentNodeType == Token.FUNCTION ||
parentNodeType == Token.CATCH ||
parentNodeType == Token.PARAM_LIST ||
parentNodeType == Token.VAR) {
return false;
}
// Not need to type first key in for in.
if (parent.isForIn() && parent.getFirstChild() == n) {
return false;
}
JSType type = n.getJSType();
if (type == null) {
type = getNativeType(UNKNOWN_TYPE);
TypedVar var = t.getTypedScope().getVar(n.getString());
if (var != null) {
JSType varType = var.getType();
if (varType != null) {
type = varType;
}
}
}
ensureTyped(t, n, type);
return true;
}
/**
* Visits a GETPROP node.
*
* @param t The node traversal object that supplies context, such as the
* scope chain to use in name lookups as well as error reporting.
* @param n The node being visited.
* @param parent The parent of <code>n</code>
*/
private void visitGetProp(NodeTraversal t, Node n, Node parent) {
// obj.prop or obj.method()
// Lots of types can appear on the left, a call to a void function can
// never be on the left. getPropertyType will decide what is acceptable
// and what isn't.
Node property = n.getLastChild();
Node objNode = n.getFirstChild();
JSType childType = getJSType(objNode);
if (childType.isDict()) {
report(t, property, TypeValidator.ILLEGAL_PROPERTY_ACCESS, "'.'", "dict");
} else if (validator.expectNotNullOrUndefined(t, n, childType,
"No properties on this expression", getNativeType(OBJECT_TYPE))) {
checkPropertyAccess(childType, property.getString(), t, n);
}
ensureTyped(t, n);
}
/**
* Emit a warning if we can prove that a property cannot possibly be
* defined on an object. Note the difference between JS and a strictly
* statically typed language: we're checking if the property
* *cannot be defined*, whereas a java compiler would check if the
* property *can be undefined*.
*/
private void checkPropertyAccess(JSType childType, String propName,
NodeTraversal t, Node n) {
// If the property type is unknown, check the object type to see if it
// can ever be defined. We explicitly exclude CHECKED_UNKNOWN (for
// properties where we've checked that it exists, or for properties on
// objects that aren't in this binary).
JSType propType = getJSType(n);
if (propType.isEquivalentTo(typeRegistry.getNativeType(UNKNOWN_TYPE))) {
childType = childType.autobox();
ObjectType objectType = ObjectType.cast(childType);
if (objectType != null) {
// We special-case object types so that checks on enums can be
// much stricter, and so that we can use hasProperty (which is much
// faster in most cases).
if (!objectType.hasProperty(propName) ||
objectType.isEquivalentTo(
typeRegistry.getNativeType(UNKNOWN_TYPE))) {
if (objectType instanceof EnumType) {
report(t, n, INEXISTENT_ENUM_ELEMENT, propName);
} else {
checkPropertyAccessHelper(objectType, propName, t, n);
}
}
} else {
checkPropertyAccessHelper(childType, propName, t, n);
}
}
}
private boolean allowLoosePropertyAccessOnNode(Node n) {
Node parent = n.getParent();
return NodeUtil.isPropertyTest(compiler, n)
// Property declaration
|| (n.isQualifiedName() && parent.isExprResult())
// Property creation
|| (n.isQualifiedName() && parent.isAssign() && parent.getFirstChild() == n);
}
private void checkPropertyAccessHelper(JSType objectType, String propName,
NodeTraversal t, Node n) {
if (!objectType.isEmptyType() && reportMissingProperties
&& (!allowLoosePropertyAccessOnNode(n) || objectType.isStruct())
&& !typeRegistry.canPropertyBeDefined(objectType, propName)) {
boolean lowConfidence =
objectType.isUnknownType() || objectType.isEquivalentTo(getNativeType(OBJECT_TYPE));
SuggestionPair pair = null;
if (!lowConfidence) {
pair = getClosestPropertySuggestion(objectType, propName);
}
if (pair != null && pair.distance * 4 < propName.length()) {
report(t, n.getLastChild(), INEXISTENT_PROPERTY_WITH_SUGGESTION, propName,
typeRegistry.getReadableTypeName(n.getFirstChild()), pair.suggestion);
} else {
DiagnosticType reportType =
lowConfidence ? POSSIBLE_INEXISTENT_PROPERTY : INEXISTENT_PROPERTY;
report(t, n.getLastChild(), reportType, propName,
typeRegistry.getReadableTypeName(n.getFirstChild()));
}
}
}
private static SuggestionPair getClosestPropertySuggestion(
JSType objectType, String propName) {
return null;
}
/**
* Visits a GETELEM node.
*
* @param t The node traversal object that supplies context, such as the
* scope chain to use in name lookups as well as error reporting.
* @param n The node being visited.
*/
private void visitGetElem(NodeTraversal t, Node n) {
validator.expectIndexMatch(
t, n, getJSType(n.getFirstChild()), getJSType(n.getLastChild()));
ensureTyped(t, n);
}
/**
* Visits a VAR node.
*
* @param t The node traversal object that supplies context, such as the
* scope chain to use in name lookups as well as error reporting.
* @param n The node being visited.
*/
private void visitVar(NodeTraversal t, Node n) {
// TODO(nicksantos): Fix this so that the doc info always shows up
// on the NAME node. We probably want to wait for the parser
// merge to fix this.
JSDocInfo varInfo = n.hasOneChild() ? n.getJSDocInfo() : null;
for (Node name : n.children()) {
Node value = name.getFirstChild();
// A null var would indicate a bug in the scope creation logic.
TypedVar var = t.getTypedScope().getVar(name.getString());
if (value != null) {
JSType valueType = getJSType(value);
JSType nameType = var.getType();
nameType = (nameType == null) ? getNativeType(UNKNOWN_TYPE) : nameType;
JSDocInfo info = name.getJSDocInfo();
if (info == null) {
info = varInfo;
}
checkEnumAlias(t, info, value);
if (var.isTypeInferred()) {
ensureTyped(t, name, valueType);
} else {
validator.expectCanAssignTo(
t, value, valueType, nameType, "initializing variable");
}
}
}
}
/**
* Visits a NEW node.
*/
private void visitNew(NodeTraversal t, Node n) {
Node constructor = n.getFirstChild();
JSType type = getJSType(constructor).restrictByNotNullOrUndefined();
if (!couldBeAConstructor(type)) {
report(t, n, NOT_A_CONSTRUCTOR);
ensureTyped(t, n);
return;
}
FunctionType fnType = type.toMaybeFunctionType();
if (fnType != null && fnType.hasInstanceType()) {
FunctionType ctorType = fnType.getInstanceType().getConstructor();
if (ctorType != null && ctorType.isAbstract()) {
report(t, n, INSTANTIATE_ABSTRACT_CLASS);
}
visitParameterList(t, n, fnType);
ensureTyped(t, n, fnType.getInstanceType());
} else {
ensureTyped(t, n);
}
}
private boolean couldBeAConstructor(JSType type) {
return type.isConstructor() || type.isEmptyType() || type.isUnknownType();
}
/**
* Check whether there's any property conflict for for a particular super
* interface
* @param t The node traversal object that supplies context
* @param n The node being visited
* @param functionName The function name being checked
* @param properties The property names in the super interfaces that have
* been visited
* @param currentProperties The property names in the super interface
* that have been visited
* @param interfaceType The super interface that is being visited
*/
private void checkInterfaceConflictProperties(NodeTraversal t, Node n,
String functionName, Map<String, ObjectType> properties,
Map<String, ObjectType> currentProperties,
ObjectType interfaceType) {
ObjectType implicitProto = interfaceType.getImplicitPrototype();
Set<String> currentPropertyNames;
if (implicitProto == null) {
// This can be the case if interfaceType is proxy to a non-existent
// object (which is a bad type annotation, but shouldn't crash).
currentPropertyNames = ImmutableSet.of();
} else {
currentPropertyNames = implicitProto.getOwnPropertyNames();
}
for (String name : currentPropertyNames) {
ObjectType oType = properties.get(name);
currentProperties.put(name, interfaceType);
if (oType != null) {
JSType thisPropType = interfaceType.getPropertyType(name);
JSType oPropType = oType.getPropertyType(name);
if (thisPropType.isSubtype(oPropType, this.subtypingMode)
|| oPropType.isSubtype(thisPropType, this.subtypingMode)
|| (thisPropType.isFunctionType()
&& oPropType.isFunctionType()
&& thisPropType
.toMaybeFunctionType()
.hasEqualCallType(oPropType.toMaybeFunctionType()))) {
continue;
}
compiler.report(
t.makeError(n, INCOMPATIBLE_EXTENDED_PROPERTY_TYPE,
functionName, name, oType.toString(),
interfaceType.toString()));
}
}
for (ObjectType iType : interfaceType.getCtorExtendedInterfaces()) {
checkInterfaceConflictProperties(t, n, functionName, properties,
currentProperties, iType);
}
}
/**
* Visits a {@link Token#FUNCTION} node.
*
* @param t The node traversal object that supplies context, such as the
* scope chain to use in name lookups as well as error reporting.
* @param n The node being visited.
*/
private void visitFunction(NodeTraversal t, Node n) {
FunctionType functionType = JSType.toMaybeFunctionType(n.getJSType());
String functionPrivateName = n.getFirstChild().getString();
if (functionType.isConstructor()) {
FunctionType baseConstructor = functionType.getSuperClassConstructor();
if (!Objects.equals(baseConstructor, getNativeType(OBJECT_FUNCTION_TYPE))
&& baseConstructor != null
&& baseConstructor.isInterface()) {
compiler.report(
t.makeError(n, CONFLICTING_EXTENDED_TYPE,
"constructor", functionPrivateName));
} else {
if (baseConstructor != null
&& baseConstructor.getSource() != null
&& baseConstructor.getSource().getBooleanProp(Node.IS_ES6_CLASS)
&& !functionType.getSource().getBooleanProp(Node.IS_ES6_CLASS)) {
compiler.report(
t.makeError(
n,
ES5_CLASS_EXTENDING_ES6_CLASS,
functionType.getDisplayName(),
baseConstructor.getDisplayName()));
}
// All interfaces are properly implemented by a class
for (JSType baseInterface : functionType.getImplementedInterfaces()) {
boolean badImplementedType = false;
ObjectType baseInterfaceObj = ObjectType.cast(baseInterface);
if (baseInterfaceObj != null) {
FunctionType interfaceConstructor =
baseInterfaceObj.getConstructor();
if (interfaceConstructor != null &&
!interfaceConstructor.isInterface()) {
badImplementedType = true;
}
} else {
badImplementedType = true;
}
if (badImplementedType) {
report(t, n, BAD_IMPLEMENTED_TYPE, functionPrivateName);
}
}
// check properties
validator.expectAllInterfaceProperties(t, n, functionType);
if (!functionType.isAbstract()) {
validator.expectAbstractMethodsImplemented(n, functionType);
}
}
} else if (functionType.isInterface()) {
// Interface must extend only interfaces
for (ObjectType extInterface : functionType.getExtendedInterfaces()) {
if (extInterface.getConstructor() != null
&& !extInterface.getConstructor().isInterface()) {
compiler.report(
t.makeError(n, CONFLICTING_EXTENDED_TYPE,
"interface", functionPrivateName));
}
}
// Check whether the extended interfaces have any conflicts
if (functionType.getExtendedInterfacesCount() > 1) {
// Only check when extending more than one interfaces
HashMap<String, ObjectType> properties = new HashMap<>();
LinkedHashMap<String, ObjectType> currentProperties = new LinkedHashMap<>();
for (ObjectType interfaceType : functionType.getExtendedInterfaces()) {
currentProperties.clear();
checkInterfaceConflictProperties(t, n, functionPrivateName,
properties, currentProperties, interfaceType);
properties.putAll(currentProperties);
}
}
List<FunctionType> loopPath = functionType.checkExtendsLoop();
if (loopPath != null) {
String strPath = "";
for (int i = 0; i < loopPath.size() - 1; i++) {
strPath += loopPath.get(i).getDisplayName() + " -> ";
}
strPath += Iterables.getLast(loopPath).getDisplayName();
compiler.report(t.makeError(n, INTERFACE_EXTENDS_LOOP,
loopPath.get(0).getDisplayName(), strPath));
}
}
}
/**
* Validate class-defining calls.
* Because JS has no 'native' syntax for defining classes, we need
* to do this manually.
*/
private void checkCallConventions(NodeTraversal t, Node n) {
SubclassRelationship relationship =
compiler.getCodingConvention().getClassesDefinedByCall(n);
TypedScope scope = t.getTypedScope();
if (relationship != null) {
ObjectType superClass = TypeValidator.getInstanceOfCtor(
scope.getVar(relationship.superclassName));
ObjectType subClass = TypeValidator.getInstanceOfCtor(
scope.getVar(relationship.subclassName));
if (relationship.type == SubclassType.INHERITS &&
superClass != null && !superClass.isEmptyType() &&
subClass != null && !subClass.isEmptyType()) {
validator.expectSuperType(t, n, superClass, subClass);
}
}
}
/**
* Visits a CALL node.
*
* @param t The node traversal object that supplies context, such as the
* scope chain to use in name lookups as well as error reporting.
* @param n The node being visited.
*/
private void visitCall(NodeTraversal t, Node n) {
checkCallConventions(t, n);
Node child = n.getFirstChild();
JSType childType = getJSType(child).restrictByNotNullOrUndefined();
if (!childType.canBeCalled()) {
report(t, n, NOT_CALLABLE, childType.toString());
ensureTyped(t, n);
return;
}
// A couple of types can be called as if they were functions.
// If it is a function type, then validate parameters.
if (childType.isFunctionType()) {
FunctionType functionType = childType.toMaybeFunctionType();
// Non-native constructors should not be called directly
// unless they specify a return type
if (functionType.isConstructor() &&
!functionType.isNativeObjectType() &&
(functionType.getReturnType().isUnknownType() ||
functionType.getReturnType().isVoidType())) {
report(t, n, CONSTRUCTOR_NOT_CALLABLE, childType.toString());
}
// Functions with explicit 'this' types must be called in a GETPROP
// or GETELEM.
if (functionType.isOrdinaryFunction() &&
!functionType.getTypeOfThis().isUnknownType() &&
!(functionType.getTypeOfThis().toObjectType() != null &&
functionType.getTypeOfThis().toObjectType().isNativeObjectType()) &&
!(child.isGetElem() ||
child.isGetProp())) {
report(t, n, EXPECTED_THIS_TYPE, functionType.toString());
}
checkAbstractMethodCall(t, n);
visitParameterList(t, n, functionType);
ensureTyped(t, n, functionType.getReturnType());
} else {
ensureTyped(t, n);
}
// TODO(nicksantos): Add something to check for calls of RegExp objects,
// which is not supported by IE. Either say something about the return type
// or warn about the non-portability of the call or both.
}
/** Check that @abstract methods are not called */
private void checkAbstractMethodCall(NodeTraversal t, Node call) {
if (NodeUtil.isFunctionObjectCall(call) || NodeUtil.isFunctionObjectApply(call)) {
Node method = call.getFirstFirstChild();
// this.foo.apply(this) should be allowed
if (method.isGetProp() && method.getFirstChild().isThis()) {
return;
}
FunctionType methodType = method.getJSType().toMaybeFunctionType();
if (methodType != null && methodType.isAbstract() && !methodType.isConstructor()) {
report(t, call, ABSTRACT_SUPER_METHOD_NOT_CALLABLE, methodType.getDisplayName());
}
} else {
// Check for cases like Base.prototype.foo() where foo is abstract
Node maybeGetProp = call.getFirstChild();
if (maybeGetProp.isGetProp() && maybeGetProp.isQualifiedName()) {
Node rootOfQName = NodeUtil.getRootOfQualifiedName(maybeGetProp);
if (rootOfQName.isName()) {
Node maybePrototype = rootOfQName.getNext();
if (maybePrototype.isString() && maybePrototype.getString().equals("prototype")) {
FunctionType methodType = maybeGetProp.getJSType().toMaybeFunctionType();
if (methodType != null && methodType.isAbstract() && !methodType.isConstructor()
&& rootOfQName.getJSType() != null && methodType.getTypeOfThis().equals(
rootOfQName.getJSType().toMaybeFunctionType().getInstanceType())) {
report(t, call, ABSTRACT_SUPER_METHOD_NOT_CALLABLE, methodType.getDisplayName());
}
}
}
}
}
}
/**
* Visits the parameters of a CALL or a NEW node.
*/
private void visitParameterList(NodeTraversal t, Node call,
FunctionType functionType) {
Iterator<Node> arguments = call.children().iterator();
arguments.next(); // skip the function name
Iterator<Node> parameters = functionType.getParameters().iterator();
int ordinal = 0;
Node parameter = null;
Node argument = null;
while (arguments.hasNext()
&& (parameters.hasNext() || (parameter != null && parameter.isVarArgs()))) {
// If there are no parameters left in the list, then the while loop
// above implies that this must be a var_args function.
if (parameters.hasNext()) {
parameter = parameters.next();
}
argument = arguments.next();
ordinal++;
validator.expectArgumentMatchesParameter(t, argument,
getJSType(argument), getJSType(parameter), call, ordinal);
}
int numArgs = call.getChildCount() - 1;
int minArgs = functionType.getMinArguments();
int maxArgs = functionType.getMaxArguments();
if (minArgs > numArgs || maxArgs < numArgs) {
report(t, call, WRONG_ARGUMENT_COUNT,
typeRegistry.getReadableTypeNameNoDeref(call.getFirstChild()),
String.valueOf(numArgs), String.valueOf(minArgs),
maxArgs != Integer.MAX_VALUE ?
" and no more than " + maxArgs + " argument(s)" : "");
}
}
/**
* Visits a RETURN node.
*
* @param t The node traversal object that supplies context, such as the
* scope chain to use in name lookups as well as error reporting.
* @param n The node being visited.
*/
private void visitReturn(NodeTraversal t, Node n) {
JSType jsType = getJSType(t.getEnclosingFunction());
if (jsType.isFunctionType()) {
FunctionType functionType = jsType.toMaybeFunctionType();
JSType returnType = functionType.getReturnType();
// if no return type is specified, undefined must be returned
// (it's a void function)
if (returnType == null) {
returnType = getNativeType(VOID_TYPE);
}
// fetching the returned value's type
Node valueNode = n.getFirstChild();
JSType actualReturnType;
if (valueNode == null) {
actualReturnType = getNativeType(VOID_TYPE);
valueNode = n;
} else {
actualReturnType = getJSType(valueNode);
}
// verifying
validator.expectCanAssignTo(t, valueNode, actualReturnType, returnType,
"inconsistent return type");
}
}
/**
* This function unifies the type checking involved in the core binary
* operators and the corresponding assignment operators. The representation
* used internally is such that common code can handle both kinds of
* operators easily.
*
* @param op The operator.
* @param t The traversal object, needed to report errors.
* @param n The node being checked.
*/
private void visitBinaryOperator(Token op, NodeTraversal t, Node n) {
Node left = n.getFirstChild();
JSType leftType = getJSType(left);
Node right = n.getLastChild();
JSType rightType = getJSType(right);
switch (op) {
case ASSIGN_LSH:
case ASSIGN_RSH:
case LSH:
case RSH:
case ASSIGN_URSH:
case URSH:
if (!leftType.matchesInt32Context()) {
report(t, left, BIT_OPERATION, NodeUtil.opToStr(n.getToken()), leftType.toString());
}
if (!rightType.matchesUint32Context()) {
report(t, right, BIT_OPERATION, NodeUtil.opToStr(n.getToken()), rightType.toString());
}
break;
case ASSIGN_DIV:
case ASSIGN_MOD:
case ASSIGN_MUL:
case ASSIGN_SUB:
case DIV:
case MOD:
case MUL:
case SUB:
validator.expectNumber(t, left, leftType, "left operand");
validator.expectNumber(t, right, rightType, "right operand");
break;
case ASSIGN_BITAND:
case ASSIGN_BITXOR:
case ASSIGN_BITOR:
case BITAND:
case BITXOR:
case BITOR:
validator.expectBitwiseable(t, left, leftType,
"bad left operand to bitwise operator");
validator.expectBitwiseable(t, right, rightType,
"bad right operand to bitwise operator");
break;
case ASSIGN_ADD:
case ADD:
break;
default:
report(t, n, UNEXPECTED_TOKEN, op.toString());
}
ensureTyped(t, n);
}
/**
* <p>Checks enum aliases.
*
* <p>We verify that the enum element type of the enum used
* for initialization is a subtype of the enum element type of
* the enum the value is being copied in.</p>
*
* <p>Example:</p>
* <pre>var myEnum = myOtherEnum;</pre>
*
* <p>Enum aliases are irregular, so we need special code for this :(</p>
*
* @param value the value used for initialization of the enum
*/
private void checkEnumAlias(
NodeTraversal t, JSDocInfo declInfo, Node value) {
if (declInfo == null || !declInfo.hasEnumParameterType()) {
return;
}
JSType valueType = getJSType(value);
if (!valueType.isEnumType()) {
return;
}
EnumType valueEnumType = valueType.toMaybeEnumType();
JSType valueEnumPrimitiveType =
valueEnumType.getElementsType().getPrimitiveType();
validator.expectCanAssignTo(t, value, valueEnumPrimitiveType,
declInfo.getEnumParameterType().evaluate(t.getTypedScope(), typeRegistry),
"incompatible enum element types");
}
/**
* This method gets the JSType from the Node argument and verifies that it is
* present.
*/
private JSType getJSType(Node n) {
JSType jsType = n.getJSType();
if (jsType == null) {
// TODO(nicksantos): This branch indicates a compiler bug, not worthy of
// halting the compilation but we should log this and analyze to track
// down why it happens. This is not critical and will be resolved over
// time as the type checker is extended.
return getNativeType(UNKNOWN_TYPE);
} else {
return jsType;
}
}
// TODO(nicksantos): TypeCheck should never be attaching types to nodes.
// All types should be attached by TypeInference. This is not true today
// for legacy reasons. There are a number of places where TypeInference
// doesn't attach a type, as a signal to TypeCheck that it needs to check
// that node's type.
/**
* Ensure that the given node has a type. If it does not have one,
* attach the UNKNOWN_TYPE.
*/
private void ensureTyped(NodeTraversal t, Node n) {
ensureTyped(t, n, getNativeType(UNKNOWN_TYPE));
}
private void ensureTyped(NodeTraversal t, Node n, JSTypeNative type) {
ensureTyped(t, n, getNativeType(type));
}
/**
* Enforces type casts, and ensures the node is typed.
*
* A cast in the way that we use it in JSDoc annotations never
* alters the generated code and therefore never can induce any runtime
* operation. What this means is that a 'cast' is really just a compile
* time constraint on the underlying value. In the future, we may add
* support for run-time casts for compiled tests.
*
* To ensure some shred of sanity, we enforce the notion that the
* type you are casting to may only meaningfully be a narrower type
* than the underlying declared type. We also invalidate optimizations
* on bad type casts.
*
* @param t The traversal object needed to report errors.
* @param n The node getting a type assigned to it.
* @param type The type to be assigned.
*/
private void ensureTyped(NodeTraversal t, Node n, JSType type) {
// Make sure FUNCTION nodes always get function type.
Preconditions.checkState(!n.isFunction() ||
type.isFunctionType() ||
type.isUnknownType());
// TODO(johnlenz): this seems like a strange place to check "@implicitCast"
JSDocInfo info = n.getJSDocInfo();
if (info != null && (info.isImplicitCast() && !inExterns)) {
String propName = n.isGetProp() ? n.getLastChild().getString() : "(missing)";
compiler.report(t.makeError(n, ILLEGAL_IMPLICIT_CAST, propName));
}
if (n.getJSType() == null) {
n.setJSType(type);
}
}
/**
* Returns the percentage of nodes typed by the type checker.
* @return a number between 0.0 and 100.0
*/
double getTypedPercent() {
int total = nullCount + unknownCount + typedCount;
return (total == 0) ? 0.0 : (100.0 * typedCount) / total;
}
private JSType getNativeType(JSTypeNative typeId) {
return typeRegistry.getNativeType(typeId);
}
/**
* Checks if current node contains js docs and checks all types specified in the js doc whether
* they have Objects with potentially invalid keys. For example: {@code
* Object<!Object, number>}. If such type is found, a warning is reported for the current node.
*/
private void checkJsdocInfoContainsObjectWithBadKey(NodeTraversal t, Node n) {
if (n.getJSDocInfo() != null) {
JSDocInfo info = n.getJSDocInfo();
checkTypeContainsObjectWithBadKey(t, n, info.getType());
checkTypeContainsObjectWithBadKey(t, n, info.getReturnType());
checkTypeContainsObjectWithBadKey(t, n, info.getTypedefType());
for (String param : info.getParameterNames()) {
checkTypeContainsObjectWithBadKey(t, n, info.getParameterType(param));
}
}
}
private void checkTypeContainsObjectWithBadKey(NodeTraversal t, Node n, JSTypeExpression type) {
if (type != null && type.getRoot().getJSType() != null) {
JSType realType = type.getRoot().getJSType();
JSType objectWithBadKey = findObjectWithNonStringifiableKey(realType, new HashSet<JSType>());
if (objectWithBadKey != null){
compiler.report(t.makeError(n, NON_STRINGIFIABLE_OBJECT_KEY, objectWithBadKey.toString()));
}
}
}
/**
* Checks whether type is stringifiable. Stringifiable is a type that can be converted to string
* and give unique results for different objects. For example objects have native toString()
* method that on chrome returns "[object Object]" for all objects making it useless when used
* as keys. At the same time native types like numbers can be safely converted to strings and
* used as keys. Also user might have provided custom toString() methods for a class making it
* suitable for using as key.
*/
private boolean isStringifiable(JSType type) {
// Check built-in types
if (type.isUnknownType() || type.isNumber() || type.isString() || type.isBooleanObjectType()
|| type.isBooleanValueType() || type.isDateType() || type.isRegexpType()
|| type.isInterface() || type.isRecordType() || type.isNullType() || type.isVoidType()) {
return true;
}
// For enums check that underlying type is stringifiable.
if (type.toMaybeEnumElementType() != null) {
return isStringifiable(type.toMaybeEnumElementType().getPrimitiveType());
}
// Array is stringifiable if it doesn't have template type or if it does have it, the template
// type must be also stringifiable.
// Good: Array, Array.<number>
// Bad: Array.<!Object>
if (type.isArrayType()) {
return true;
}
if (type.isTemplatizedType()) {
TemplatizedType templatizedType = type.toMaybeTemplatizedType();
if (templatizedType.getReferencedType().isArrayType()) {
return isStringifiable(templatizedType.getTemplateTypes().get(0));
}
}
// Named types are usually @typedefs. For such types we need to check underlying type specified
// in @typedef annotation.
if (type instanceof NamedType) {
return isStringifiable(((NamedType) type).getReferencedType());
}
// For union type every alternate must be stringifiable.
if (type.isUnionType()) {
for (JSType alternateType : type.toMaybeUnionType().getAlternates()) {
if (!isStringifiable(alternateType)) {
return false;
}
}
return true;
}
// Handle interfaces and classes.
if (type.isObject()) {
ObjectType objectType = type.toMaybeObjectType();
JSType constructor = objectType.getConstructor();
// Interfaces considered stringifiable as user might implement toString() method in
// classes-implementations.
if (constructor != null && constructor.isInterface()) {
return true;
}
// This is user-defined class so check if it has custom toString() method.
return classHasToString(objectType);
}
return false;
}
/**
* Checks whether current type is Object type with non-stringifable key.
*/
private boolean isObjectTypeWithNonStringifiableKey(JSType type) {
if (!type.isTemplatizedType()) {
return false;
}
TemplatizedType templatizedType = type.toMaybeTemplatizedType();
if (templatizedType.getReferencedType().isNativeObjectType()
&& templatizedType.getTemplateTypes().size() > 1) {
return !isStringifiable(templatizedType.getTemplateTypes().get(0));
} else {
return false;
}
}
/**
* Checks whether type (or one of its component if is composed type like union or templatized
* type) has Object with non-stringifiable key. For example {@code Object.<!Object, number>}.
*
* @return non-stringifiable type which is used as key or null if all there are no such types.
*/
private JSType findObjectWithNonStringifiableKey(JSType type, Set<JSType> alreadyCheckedTypes) {
if (alreadyCheckedTypes.contains(type)) {
// This can happen in recursive types. Current type already being checked earlier in
// stacktrace so now we just skip it.
return null;
} else {
alreadyCheckedTypes.add(type);
}
if (isObjectTypeWithNonStringifiableKey(type)) {
return type;
}
if (type.isUnionType()) {
for (JSType alternateType : type.toMaybeUnionType().getAlternates()) {
JSType result = findObjectWithNonStringifiableKey(alternateType, alreadyCheckedTypes);
if (result != null) {
return result;
}
}
}
if (type.isTemplatizedType()) {
for (JSType templateType : type.toMaybeTemplatizedType().getTemplateTypes()) {
JSType result = findObjectWithNonStringifiableKey(templateType, alreadyCheckedTypes);
if (result != null) {
return result;
}
}
}
if (type.isOrdinaryFunction()) {
FunctionType function = type.toMaybeFunctionType();
for (Node parameter : function.getParameters()) {
JSType result =
findObjectWithNonStringifiableKey(parameter.getJSType(), alreadyCheckedTypes);
if (result != null) {
return result;
}
}
return findObjectWithNonStringifiableKey(function.getReturnType(), alreadyCheckedTypes);
}
return null;
}
/**
* Checks whether class has overridden toString() method. All objects has native toString()
* method but we ignore it as it is not useful so we need user-provided toString() method.
*/
private boolean classHasToString(ObjectType type) {
Property toStringProperty = type.getOwnSlot("toString");
if (toStringProperty != null) {
return toStringProperty.getType().isFunctionType();
}
ObjectType parent = type.getParentScope();
if (parent != null && !parent.isNativeObjectType()) {
return classHasToString(parent);
}
return false;
}
}