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      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 
     17 package com.android.inputmethod.latin.utils;
     18 
     19 import android.test.AndroidTestCase;
     20 import android.test.suitebuilder.annotation.SmallTest;
     21 
     22 @SmallTest
     23 public class EditDistanceTests extends AndroidTestCase {
     24     /*
     25      * dist(kitten, sitting) == 3
     26      *
     27      * kitten-
     28      * .|||.|
     29      * sitting
     30      */
     31     public void testExample1() {
     32         final int dist = BinaryDictionaryUtils.editDistance("kitten", "sitting");
     33         assertEquals("edit distance between 'kitten' and 'sitting' is 3",
     34                 3, dist);
     35     }
     36 
     37     /*
     38      * dist(Sunday, Saturday) == 3
     39      *
     40      * Saturday
     41      * |  |.|||
     42      * S--unday
     43      */
     44     public void testExample2() {
     45         final int dist = BinaryDictionaryUtils.editDistance("Saturday", "Sunday");
     46         assertEquals("edit distance between 'Saturday' and 'Sunday' is 3",
     47                 3, dist);
     48     }
     49 
     50     public void testBothEmpty() {
     51         final int dist = BinaryDictionaryUtils.editDistance("", "");
     52         assertEquals("when both string are empty, no edits are needed",
     53                 0, dist);
     54     }
     55 
     56     public void testFirstArgIsEmpty() {
     57         final int dist = BinaryDictionaryUtils.editDistance("", "aaaa");
     58         assertEquals("when only one string of the arguments is empty,"
     59                  + " the edit distance is the length of the other.",
     60                  4, dist);
     61     }
     62 
     63     public void testSecoondArgIsEmpty() {
     64         final int dist = BinaryDictionaryUtils.editDistance("aaaa", "");
     65         assertEquals("when only one string of the arguments is empty,"
     66                  + " the edit distance is the length of the other.",
     67                  4, dist);
     68     }
     69 
     70     public void testSameStrings() {
     71         final String arg1 = "The quick brown fox jumps over the lazy dog.";
     72         final String arg2 = "The quick brown fox jumps over the lazy dog.";
     73         final int dist = BinaryDictionaryUtils.editDistance(arg1, arg2);
     74         assertEquals("when same strings are passed, distance equals 0.",
     75                 0, dist);
     76     }
     77 
     78     public void testSameReference() {
     79         final String arg = "The quick brown fox jumps over the lazy dog.";
     80         final int dist = BinaryDictionaryUtils.editDistance(arg, arg);
     81         assertEquals("when same string references are passed, the distance equals 0.",
     82                 0, dist);
     83     }
     84 
     85     public void testNullArg() {
     86         try {
     87             BinaryDictionaryUtils.editDistance(null, "aaa");
     88             fail("IllegalArgumentException should be thrown.");
     89         } catch (Exception e) {
     90             assertTrue(e instanceof IllegalArgumentException);
     91         }
     92         try {
     93             BinaryDictionaryUtils.editDistance("aaa", null);
     94             fail("IllegalArgumentException should be thrown.");
     95         } catch (Exception e) {
     96             assertTrue(e instanceof IllegalArgumentException);
     97         }
     98     }
     99 }
    100