/*
* Copyright 2013 Google Inc.
*
* 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.gwt.emultest.java.lang;
import com.google.gwt.junit.client.GWTTestCase;
/**
* Unit tests for the GWT emulation of java.lang.Throwable class.
*/
public class ThrowableTest extends GWTTestCase {
// Line number for exception thrown in throwException below.
private static final int THROWN_EXCEPTION_LINE_NUMBER = 36;
public String getModuleName() {
return "com.google.gwt.emultest.EmulSuite";
}
private void throwException(String arg) {
// prevent inlining by double referencing arg
String result = arg.substring(1) + "test";
// THROWN_EXCEPTION_LINE_NUMBER should point to this line below
throw new RuntimeException(result.charAt(0) + result.substring(1));
}
public void testStackTraceContainsConstructorLineNumber() {
// NOTE: changing the line number of this object creation will affect
// the test case.
final int lineNumber = 43; // should be the next line.
Throwable throwable = new Throwable("stacktrace");
StackTraceElement[] trace = throwable.getStackTrace();
assertNotNull(trace);
String traceStr = getTraceAsString(trace);
assertTrue("stack trace has length: " + trace.length + ", full trace: \n" +
traceStr, trace.length > 2);
StackTraceElement e = findTraceElementForThisFile(trace,
(isObfuscated(trace) ? 7 : 3));
assertNotNull("Unable to find trace element: \n" + traceStr, e);
assertEquals(lineNumber, e.getLineNumber());
}
public void testGetStackTraceOnThrownException() {
RuntimeException caughtException = null;
try {
throwException("Runtime Exception");
} catch (RuntimeException exception) {
caughtException = exception;
}
assertNotNull(caughtException);
StackTraceElement[] trace = caughtException.getStackTrace();
assertNotNull(trace);
String traceStr = getTraceAsString(trace);
StackTraceElement e = findTraceElementForThisFile(trace,
(isObfuscated(trace) ? 9 : 5));
assertNotNull("Unable to find trace element: \n" + traceStr, e);
assertEquals(traceStr, THROWN_EXCEPTION_LINE_NUMBER,
e.getLineNumber());
// Don't compare method names for obfuscated cases.
if (!isObfuscated(trace)) {
assertTrue("actual method is <<" + e.getMethodName() + ">>" +
", full trace is:\n" + traceStr,
e.getMethodName().contains("throwException"));
}
}
public void testSetStackTrace() {
Throwable throwable = new Throwable("stacktrace");
throwable.fillInStackTrace();
StackTraceElement[] newStackTrace = new StackTraceElement[2];
newStackTrace[0] = new StackTraceElement("TestClass", "testMethod", "fakefile", 10);
newStackTrace[1] = new StackTraceElement("TestClass", "testCaller", "fakefile2", 97);
throwable.setStackTrace(newStackTrace);
StackTraceElement[] trace = throwable.getStackTrace();
assertNotNull(trace);
assertEquals(2, trace.length);
assertEquals("TestClass", trace[0].getClassName());
assertEquals("testMethod", trace[0].getMethodName());
assertEquals("fakefile", trace[0].getFileName());
assertEquals(10, trace[0].getLineNumber());
assertEquals("TestClass.testMethod(fakefile:10)", trace[0].toString());
assertEquals("TestClass.testCaller(fakefile2:97)", trace[1].toString());
}
// Returns true if stack trace is obfuscated.
private boolean isObfuscated(StackTraceElement[] trace) {
if (trace == null || trace.length == 0) {
throw new RuntimeException("null trace");
}
return trace[0].getClassName().equals("Unknown");
}
// Finds first trace element that mentions this file, ThrowableTest, going
// at most maxDepthToExamine depth.
private StackTraceElement findTraceElementForThisFile(
StackTraceElement[] trace, int maxDepthToExamine) {
if (trace == null) {
throw new RuntimeException("null trace");
}
for (int i = 0; i < maxDepthToExamine && i < trace.length; i++) {
StackTraceElement e = trace[i];
if (e.getFileName() != null &&
e.getFileName().contains("ThrowableTest")) {
return e;
}
}
return null;
}
private String getTraceAsString(StackTraceElement[] trace) {
if (trace == null) {
throw new RuntimeException("null trace");
}
String result = "";
for (StackTraceElement e : trace) {
result += e.toString() + "\n";
}
return result;
}
}