src/test/examplesJava11/backport/StringBackportJava11Test.java

// Copyright (c) 2019, the R8 project authors. Please see the AUTHORS file
// for details. All rights reserved. Use of this source code is governed by a
// BSD-style license that can be found in the LICENSE file.

package backport;

import com.android.tools.r8.TestParameters;
import com.android.tools.r8.TestRuntime.CfVm;
import com.android.tools.r8.desugar.backports.AbstractBackportTest;
import com.android.tools.r8.utils.AndroidApiLevel;
import org.junit.runner.RunWith;
import org.junit.runners.Parameterized;
import org.junit.runners.Parameterized.Parameters;

@RunWith(Parameterized.class)
public final class StringBackportJava11Test extends AbstractBackportTest {
  @Parameters(name = "{0}")
  public static Iterable<?> data() {
    return getTestParameters()
        .withDexRuntimes()
        .withCfRuntimesStartingFromIncluding(CfVm.JDK11)
        .withAllApiLevelsAlsoForCf()
        .build();
  }

  public StringBackportJava11Test(TestParameters parameters) {
    super(parameters, String.class, StringBackportJava11Main.class);
    // Note: The methods in this test exist in android.jar from Android T. When R8 builds targeting
    // Java 11 move these tests to StringBackportTest (out of examplesJava11).

    registerTarget(AndroidApiLevel.T, 49);
  }

  public static class StringBackportJava11Main {
    public static void main(String[] args) {
      testRepeat();
      testIsBlank();
      testStrip();
      testStripLeading();
      testStripTrailing();
    }

    private static void testRepeat() {
      try {
        throw new AssertionError("hey".repeat(-1));
      } catch (IllegalArgumentException e) {
        assertEquals("count is negative: -1", e.getMessage());
      }

      assertEquals("", "".repeat(0));
      assertEquals("", "".repeat(1));
      assertEquals("", "".repeat(2));

      assertEquals("", "hey".repeat(0));
      assertEquals("hey", "hey".repeat(1));
      assertEquals("heyhey", "hey".repeat(2));
      assertEquals("heyheyhey", "hey".repeat(3));
      assertEquals("heyheyheyhey", "hey".repeat(4));

      try {
        "\u03B1\u03B2".repeat(Integer.MAX_VALUE);
        throw new AssertionError("Expected to throw OutOfMemoryError");
      } catch (OutOfMemoryError e) {
        // Expected.
      }
    }

    /** Per {@link Character#isWhitespace(int)} */
    private static final String WHITESPACE =
        ""
            // Unicode "Zs" category:
            + "\u0020" + "\u1680"
            // + "\u00A0" Exception per Javadoc
            + "\u1680" + "\u2000" + "\u2001" + "\u2002" + "\u2003" + "\u2004" + "\u2005" + "\u2006"
            // + "\u2007" Exception per Javadoc
            + "\u2008" + "\u2009" + "\u200A"
            // + "\u200F" Exception per Javadoc
            // + "\u205F" Not honored on Android 4.0.4
            + "\u3000"
            // Unicode "Zl" category:
            + "\u2028"
            // Unicode "Zp" category:
            + "\u2029"
            // Others:
            + "\t" + "\n" + "\u000B" + "\f" + "\r" + "\u001C" + "\u001D" + "\u001E" + "\u001F";

    public static void testIsBlank() {
      assertEquals(true, "".isBlank());
      assertEquals(true, WHITESPACE.isBlank());

      // Android <=4.0.4 does not recognize this as whitespace. Just ensure local consistency.
      assertEquals(Character.isWhitespace(0x205F), "\u205F".isBlank());

      assertEquals(false, "a".isBlank());
      assertEquals(false, "å".isBlank());
      assertEquals(false, "a\u030A".isBlank());
      assertEquals(false, "\uD83D\uDE00".isBlank());
      assertEquals(false, (WHITESPACE + "a").isBlank());
      assertEquals(false, ("a" + WHITESPACE).isBlank());
    }

    public static void testStrip() {
      assertEquals("", "".strip());
      assertEquals("", WHITESPACE.strip());
      assertEquals("a", "a".strip());
      assertEquals("a", (WHITESPACE + "a").strip());
      assertEquals("a", ("a" + WHITESPACE).strip());
      assertEquals("a", (WHITESPACE + "a" + WHITESPACE).strip());
      assertEquals("a" + WHITESPACE + "a", ("a" + WHITESPACE + "a").strip());
      assertEquals("a" + WHITESPACE + "a", (WHITESPACE + "a" + WHITESPACE + "a").strip());
      assertEquals("a" + WHITESPACE + "a", ("a" + WHITESPACE + "a" + WHITESPACE).strip());
      assertEquals(
          "a" + WHITESPACE + "a", (WHITESPACE + "a" + WHITESPACE + "a" + WHITESPACE).strip());
    }

    public static void testStripLeading() {
      assertEquals("", "".stripLeading());
      assertEquals("", WHITESPACE.stripLeading());
      assertEquals("a", "a".stripLeading());
      assertEquals("a", (WHITESPACE + "a").stripLeading());
      assertEquals("a" + WHITESPACE, ("a" + WHITESPACE).stripLeading());
      assertEquals("a" + WHITESPACE, (WHITESPACE + "a" + WHITESPACE).stripLeading());
      assertEquals("a" + WHITESPACE + "a", ("a" + WHITESPACE + "a").stripLeading());
      assertEquals("a" + WHITESPACE + "a", (WHITESPACE + "a" + WHITESPACE + "a").stripLeading());
      assertEquals(
          "a" + WHITESPACE + "a" + WHITESPACE,
          ("a" + WHITESPACE + "a" + WHITESPACE).stripLeading());
      assertEquals(
          "a" + WHITESPACE + "a" + WHITESPACE,
          (WHITESPACE + "a" + WHITESPACE + "a" + WHITESPACE).stripLeading());
    }

    public static void testStripTrailing() {
      assertEquals("", "".stripTrailing());
      assertEquals("", WHITESPACE.stripTrailing());
      assertEquals("a", "a".stripTrailing());
      assertEquals(WHITESPACE + "a", (WHITESPACE + "a").stripTrailing());
      assertEquals("a", ("a" + WHITESPACE).stripTrailing());
      assertEquals(WHITESPACE + "a", (WHITESPACE + "a" + WHITESPACE).stripTrailing());
      assertEquals("a" + WHITESPACE + "a", ("a" + WHITESPACE + "a").stripTrailing());
      assertEquals(
          WHITESPACE + "a" + WHITESPACE + "a",
          (WHITESPACE + "a" + WHITESPACE + "a").stripTrailing());
      assertEquals("a" + WHITESPACE + "a", ("a" + WHITESPACE + "a" + WHITESPACE).stripTrailing());
      assertEquals(
          WHITESPACE + "a" + WHITESPACE + "a",
          (WHITESPACE + "a" + WHITESPACE + "a" + WHITESPACE).stripTrailing());
    }

    private static void assertEquals(Object expected, Object actual) {
      if (expected != actual && (expected == null || !expected.equals(actual))) {
        throw new AssertionError("Expected <" + expected + "> but was <" + actual + '>');
      }
    }
  }
}