Java example source code file (EscaperAsserts.java)

This example Java source code file (EscaperAsserts.java) is included in the alvinalexander.com "Java Source Code Warehouse" project. The intent of this project is to help you "Learn Java by Example" ^TM.

Learn more about this Java project at its project page.

Java - Java tags/keywords

beta, escaperasserts, gwtcompatible, ioexception, nullpointerexception, string

The EscaperAsserts.java Java example source code

/*
 * Copyright (C) 2009 The Guava 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.common.escape.testing;

import static com.google.common.escape.Escapers.computeReplacement;

import com.google.common.annotations.Beta;
import com.google.common.annotations.GwtCompatible;
import com.google.common.escape.CharEscaper;
import com.google.common.escape.Escaper;
import com.google.common.escape.UnicodeEscaper;

import junit.framework.Assert;

import java.io.IOException;

/**
 * Extra assert methods for testing Escaper implementations.
 *
 * @author David Beaumont
 * @since 15.0
 */
@Beta
@GwtCompatible
public final class EscaperAsserts {
  private EscaperAsserts() {}

  /**
   * Asserts that an escaper behaves correctly with respect to null inputs.
   *
   * @param escaper the non-null escaper to test
   * @throws IOException
   */
  public static void assertBasic(Escaper escaper) throws IOException {
    // Escapers operate on characters: no characters, no escaping.
    Assert.assertEquals("", escaper.escape(""));
    // Assert that escapers throw null pointer exceptions.
    try {
      escaper.escape((String) null);
      Assert.fail("exception not thrown when escaping a null string");
    } catch (NullPointerException e) {
      // pass
    }
  }

  /**
   * Asserts that an escaper escapes the given character into the expected
   * string.
   *
   * @param escaper the non-null escaper to test
   * @param expected the expected output string
   * @param c the character to escape
   */
  public static void assertEscaping(CharEscaper escaper, String expected,
      char c) {

    String escaped = computeReplacement(escaper, c);
    Assert.assertNotNull(escaped);
    Assert.assertEquals(expected, escaped);
  }

  /**
   * Asserts that an escaper does not escape the given character.
   *
   * @param escaper the non-null escaper to test
   * @param c the character to test
   */
  public static void assertUnescaped(CharEscaper escaper, char c) {
    Assert.assertNull(computeReplacement(escaper, c));
  }

  /**
   * Asserts that a Unicode escaper escapes the given code point into the
   * expected string.
   *
   * @param escaper the non-null escaper to test
   * @param expected the expected output string
   * @param cp the Unicode code point to escape
   */
  public static void assertEscaping(UnicodeEscaper escaper, String expected,
      int cp) {

    String escaped = computeReplacement(escaper, cp);
    Assert.assertNotNull(escaped);
    Assert.assertEquals(expected, escaped);
  }

  /**
   * Asserts that a Unicode escaper does not escape the given character.
   *
   * @param escaper the non-null escaper to test
   * @param cp the Unicode code point to test
   */
  public static void assertUnescaped(UnicodeEscaper escaper, int cp) {
    Assert.assertNull(computeReplacement(escaper, cp));
  }

  /**
   * Asserts that a Unicode escaper escapes the given hi/lo surrogate pair into
   * the expected string.
   *
   * @param escaper the non-null escaper to test
   * @param expected the expected output string
   * @param hi the high surrogate pair character
   * @param lo the low surrogate pair character
   */
  public static void assertUnicodeEscaping(UnicodeEscaper escaper,
      String expected, char hi, char lo) {

    int cp = Character.toCodePoint(hi, lo);
    String escaped = computeReplacement(escaper, cp);
    Assert.assertNotNull(escaped);
    Assert.assertEquals(expected, escaped);
  }
}