test/langtools/tools/javac/tree/PrettyCharLiteral.java

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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 */

/*
 * @test
 * @bug 8340568
 * @summary Incorrect escaping of single quotes when pretty-printing character literals
 * @modules jdk.compiler/com.sun.tools.javac.api
 *          jdk.compiler/com.sun.tools.javac.file
 *          jdk.compiler/com.sun.tools.javac.tree
 *          jdk.compiler/com.sun.tools.javac.util
 */

import com.sun.tools.javac.file.JavacFileManager;
import com.sun.tools.javac.tree.Pretty;
import com.sun.tools.javac.tree.TreeMaker;
import com.sun.tools.javac.util.Context;

import java.io.IOException;
import java.io.StringWriter;

public class PrettyCharLiteral {
    public static void main(String... args) throws Exception {
        new PrettyCharLiteral().run();
    }

    private final TreeMaker make;

    private PrettyCharLiteral() {
        Context ctx = new Context();
        JavacFileManager.preRegister(ctx);
        this.make = TreeMaker.instance(ctx);
    }

    void run() throws Exception {
        assertEquals(
                prettyPrintLiteral('\''),
                """
                '\\''
                """.trim());
        assertEquals(
                prettyPrintLiteral('"'),
                """
                '"'
                """.trim());
        assertEquals(
                prettyPrintLiteral("'"),
                """
                "'"
                """.trim());
        assertEquals(
                prettyPrintLiteral("\""),
                """
                "\\""
                """.trim());
    }

    private void assertEquals(String actual, String expected) {
        if (!actual.equals(expected)) {
            throw new AssertionError("expected: " + expected + ", actual: " + actual);
        }
    }

    private String prettyPrintLiteral(Object value) throws IOException {
        StringWriter sw = new StringWriter();
        new Pretty(sw, true).printExpr(make.Literal(value));
        return sw.toString();
    }
}