1/*
2 * Copyright (C) 2010 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 *      http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17package com.android.inputmethod.latin;
18
19import android.test.AndroidTestCase;
20
21public class EditDistanceTests extends AndroidTestCase {
22    @Override
23    protected void setUp() throws Exception {
24        super.setUp();
25    }
26
27    @Override
28    protected void tearDown() throws Exception {
29        super.tearDown();
30    }
31
32    /*
33     * dist(kitten, sitting) == 3
34     *
35     * kitten-
36     * .|||.|
37     * sitting
38     */
39    public void testExample1() {
40        final int dist = Utils.editDistance("kitten", "sitting");
41        assertEquals("edit distance between 'kitten' and 'sitting' is 3",
42                3, dist);
43    }
44
45    /*
46     * dist(Sunday, Saturday) == 3
47     *
48     * Saturday
49     * |  |.|||
50     * S--unday
51     */
52    public void testExample2() {
53        final int dist = Utils.editDistance("Saturday", "Sunday");
54        assertEquals("edit distance between 'Saturday' and 'Sunday' is 3",
55                3, dist);
56    }
57
58    public void testBothEmpty() {
59        final int dist = Utils.editDistance("", "");
60        assertEquals("when both string are empty, no edits are needed",
61                0, dist);
62    }
63
64    public void testFirstArgIsEmpty() {
65        final int dist = Utils.editDistance("", "aaaa");
66        assertEquals("when only one string of the arguments is empty,"
67                 + " the edit distance is the length of the other.",
68                 4, dist);
69    }
70
71    public void testSecoondArgIsEmpty() {
72        final int dist = Utils.editDistance("aaaa", "");
73        assertEquals("when only one string of the arguments is empty,"
74                 + " the edit distance is the length of the other.",
75                 4, dist);
76    }
77
78    public void testSameStrings() {
79        final String arg1 = "The quick brown fox jumps over the lazy dog.";
80        final String arg2 = "The quick brown fox jumps over the lazy dog.";
81        final int dist = Utils.editDistance(arg1, arg2);
82        assertEquals("when same strings are passed, distance equals 0.",
83                0, dist);
84    }
85
86    public void testSameReference() {
87        final String arg = "The quick brown fox jumps over the lazy dog.";
88        final int dist = Utils.editDistance(arg, arg);
89        assertEquals("when same string references are passed, the distance equals 0.",
90                0, dist);
91    }
92
93    public void testNullArg() {
94        try {
95            Utils.editDistance(null, "aaa");
96            fail("IllegalArgumentException should be thrown.");
97        } catch (Exception e) {
98            assertTrue(e instanceof IllegalArgumentException);
99        }
100        try {
101            Utils.editDistance("aaa", null);
102            fail("IllegalArgumentException should be thrown.");
103        } catch (Exception e) {
104            assertTrue(e instanceof IllegalArgumentException);
105        }
106    }
107}
108