Simple.java

import java.util.regex.Pattern;
import org.checkerframework.checker.regex.qual.Regex;

public class Simple {

    void regString() {
        String s1 = "validRegex";
        String s2 = "(InvalidRegex";
    }

    void validRegString() {
        @Regex String s1 = "validRegex";
        //:: error: (assignment.type.incompatible)
        @Regex String s2 = "(InvalidRegex"; // error
    }

    void compileCall() {
        Pattern.compile("test.*[^123]$");
        //:: error: (argument.type.incompatible)
        Pattern.compile("$test.*[^123"); // error
    }

    void requireValidReg(@Regex String reg, String nonReg) {
        Pattern.compile(reg);
        //:: error: (argument.type.incompatible)
        Pattern.compile(nonReg); // error
    }

    void testAddition(@Regex String reg, String nonReg) {
        @Regex String s1 = reg;
        @Regex String s2 = reg + "d.*sf";
        @Regex String s3 = reg + reg;

        //:: error: (assignment.type.incompatible)
        @Regex String n1 = nonReg; // error
        //:: error: (assignment.type.incompatible)
        @Regex String n2 = reg + "(df"; // error
        //:: error: (assignment.type.incompatible)
        @Regex String n3 = reg + nonReg; // error

        //:: error: (assignment.type.incompatible)
        @Regex String o1 = nonReg; // error
        //:: error: (assignment.type.incompatible)
        @Regex String o2 = nonReg + "sdf"; // error
        //:: error: (assignment.type.incompatible)
        @Regex String o3 = nonReg + reg; // error
    }

    @Regex String regex = "()";
    String nonRegex = "()";

    void testCompoundConcatenation() {
        takesRegex(regex);
        //:: error: (compound.assignment.type.incompatible)
        regex += ")"; // error
        takesRegex(regex);

        nonRegex = "()";
        // nonRegex is refined by flow to be a regular expression
        takesRegex(nonRegex);
        nonRegex += ")";
        //:: error: (argument.type.incompatible)
        takesRegex(nonRegex); // error
    }

    void takesRegex(@Regex String s) {}

    void testChar() {
        @Regex char c1 = 'c';
        @Regex Character c2 = 'c';

        //:: error: (assignment.type.incompatible)
        @Regex char c3 = '('; // error
        //:: error: (assignment.type.incompatible)
        @Regex Character c4 = '('; // error
    }

    void testCharConcatenation() {
        @Regex String s1 = "rege" + 'x';
        @Regex String s2 = 'r' + "egex";

        //:: error: (assignment.type.incompatible)
        @Regex String s4 = "rege" + '('; // error
        //:: error: (assignment.type.incompatible)
        @Regex String s5 = "reg(" + 'x'; // error
        //:: error: (assignment.type.incompatible)
        @Regex String s6 = '(' + "egex"; // error
        //:: error: (assignment.type.incompatible)
        @Regex String s7 = 'r' + "ege("; // error
    }

    //    TODO: Uncomment this once isValidUse works better. See RegexChecker.isValidUse for details.
    //    class TestAllowedTypes {
    //        @Regex CharSequence cs;
    //        @Regex String s11;
    //        @Regex StringBuilder sb;
    //        @Regex Segment s21;
    //        @Regex char c;
    //        @Regex Pattern p;
    //        @Regex Matcher m;
    //
    //        //:: error: (type.invalid)
    //        @Regex Object o;   // error
    //        //:: error: (type.invalid)
    //        @Regex List<String> l;   // error
    //        //:: error: (type.invalid)
    //        ArrayList<@Regex Double> al;   // error
    //        //:: error: (type.invalid)
    //        @Regex int i;   // error
    //        //:: error: (type.invalid)
    //        @Regex boolean b;   // error
    //    }

    //    TODO: This is not supported until the checker supports getting explicit
    //    annotations from local variables (instead of just fields.)
    //    void testAllowedTypes() {
    //        @Regex CharSequence cs;
    //        @Regex String s11;
    //        @Regex StringBuilder sb;
    //        @Regex Segment s21;
    //        @Regex char c;
    //
    //        //:: error: (type.invalid)
    //        @Regex Object o;   // error
    //        //:: error: (type.invalid)
    //        @Regex List<String> l;   // error
    //        //:: error: (type.invalid)
    //        ArrayList<@Regex Double> al;   // error
    //        //:: error: (type.invalid)
    //        @Regex int i;   // error
    //        //:: error: (type.invalid)
    //        @Regex boolean b;   // error
    //
    //        @Regex String regex = "a";
    //        //:: error: (argument.type.incompatible)
    //        regex += "(";
    //
    //        String nonRegex = "a";
    //        nonRegex += "(";
    //    }

    void testPatternLiteral() {
        Pattern.compile("non(", Pattern.LITERAL);
        Pattern.compile(foo("regex"), Pattern.LITERAL);

        //:: error: (argument.type.incompatible)
        Pattern.compile(foo("regex("), Pattern.LITERAL); // error
        //:: error: (argument.type.incompatible)
        Pattern.compile("non("); // error
        //:: error: (argument.type.incompatible)
        Pattern.compile(foo("regex")); // error
        //:: error: (argument.type.incompatible)
        Pattern.compile("non(", Pattern.CASE_INSENSITIVE); // error
    }

    public static String foo(@Regex String s) {
        return "non((";
    }

    //    TODO: This is not supported until the framework can read explicit
    //    annotations from arrays.
    //    void testArrayAllowedTypes() {
    //        @Regex char[] ca1;
    //        char @Regex [] ca2;
    //        @Regex char @Regex [] ca3;
    //        @Regex String[] s1;
    //
    //        //:: error: (type.invalid)
    //        @Regex double[] da1;   // error
    //        //:: error: (type.invalid)
    //        double @Regex [] da2;   // error
    //        //:: error: (type.invalid)
    //        @Regex double @Regex [] da3;   // error
    //        //:: error: (type.invalid)
    //        String @Regex [] s2;    // error
    //    }

    //    TODO: This is not supported until the Regex Checker supports flow
    //    sensitivity. See the associated comment at
    //    org.checkerframework.checker/regex/RegexAnnotatedTypeFactory.java:visitNewArray
    //    void testCharArrays(char c, @Regex char r) {
    //        char @Regex [] c1 = {'r', 'e', 'g', 'e', 'x'};
    //        char @Regex [] c2 = {'(', 'r', 'e', 'g', 'e', 'x', ')', '.', '*'};
    //        char @Regex [] c3 = {r, 'e', 'g', 'e', 'x'};
    //
    //        //:: error: (assignment.type.incompatible)
    //        char @Regex [] c4 = {'(', 'r', 'e', 'g', 'e', 'x'};   // error
    //        //:: error: (assignment.type.incompatible)
    //        char @Regex [] c5 = {c, '.', '*'};   // error
    //    }
}