tests/string-lerp.js

   1 var JS = this.JS || require('jstest');
   2 var m = require('../string-lerp');
   3
   4 var HALF_POOS = /\uD83D\uD83D|\uDCA9\uDCA9|\uD83D$/;
   5 var UNUSUAL_Q = 'q\u0307\u0323';
   6
   7 JS.Test.describe('fast lerp', function () { with (this) {
   8     var lerp = m.fastLerp;
   9     var A = "Do you like green eggs and ham?";
  10     var B = "I do not like them, Sam-I-am.";
  11
  12     it("handles empty strings", function () { with (this) {
  13         assertEqual("", lerp("", "", -1));
  14         assertEqual("", lerp("", "", 0));
  15         assertEqual("", lerp("", "", 0.5));
  16         assertEqual("", lerp("", "", 1));
  17         assertEqual("", lerp("", "", 2));
  18     }});
  19
  20     it("maintains identity", function () { with (this) {
  21         for (var i = -1; i < 2; i += 1/1024) {
  22             assertEqual(A, lerp(A, A, i));
  23             assertEqual(B, lerp(B, B, i));
  24         }
  25     }});
  26
  27     it("handles lows", function () { with (this) {
  28         assertEqual(A, lerp(A, B, -Infinity));
  29         assertEqual(A, lerp(A, B, -1));
  30         assertEqual(A, lerp(A, B, 0));
  31     }});
  32
  33     it("handles highs", function () { with (this) {
  34         assertEqual(B, lerp(A, B, 1));
  35         assertEqual(B, lerp(A, B, 2));
  36         assertEqual(B, lerp(A, B, Infinity));
  37     }});
  38
  39     it("crams strings together", function () { with (this) {
  40         assertEqual("I do not ke green eggs and ham?", lerp(A, B, 0.3));
  41         assertEqual("I do not like tn eggs and ham?", lerp(A, B, 0.5));
  42         assertEqual("I do not like them, Sam-I-am?", lerp(A, B, 0.98));
  43     }});
  44
  45     it("doesn't make half a poo", function () { with (this) {
  46         var poos = "\uD83D\uDCA9\uD83D\uDCA9\uD83D\uDCA9\uD83D\uDCA9";
  47         assertEqual("\uD83D\uDCA9\uD83D\uDCA9", lerp("", poos, 0.5));
  48         assertEqual("\uD83D\uDCA9", lerp("", poos, 0.35));
  49
  50         for (var i = 0; i <= 1; i += 1/256)
  51             assertNot(lerp("", poos, i).match(HALF_POOS));
  52     }});
  53
  54     it("doesn't misplace combining marks", function () { with (this) {
  55         for (var i = 0; i <= 1; i += 1/256) {
  56             var r = lerp("a", UNUSUAL_Q, i);
  57             assert(r === "a" || r === UNUSUAL_Q);
  58         }
  59     }});
  60 }});
  61
  62 JS.Test.describe('diff lerp', function () { with (this) {
  63     var lerp = m.diffLerp;
  64     var A = "Do you like green eggs and ham?";
  65     var B = "I do not like them, Sam-I-am.";
  66
  67     it("handles empty strings", function () { with (this) {
  68         assertEqual("", lerp("", "", -1));
  69         assertEqual("", lerp("", "", 0));
  70         assertEqual("", lerp("", "", 0.5));
  71         assertEqual("", lerp("", "", 1));
  72         assertEqual("", lerp("", "", 2));
  73     }});
  74
  75     it("maintains identity", function () { with (this) {
  76         for (var i = -1; i < 2; i += 1/1024) {
  77             assertEqual(A, lerp(A, A, i));
  78             assertEqual(B, lerp(B, B, i));
  79         }
  80     }});
  81
  82     it("handles lows", function () { with (this) {
  83         assertEqual(A, lerp(A, B, -Infinity));
  84         assertEqual(A, lerp(A, B, -1));
  85         assertEqual(A, lerp(A, B, 0));
  86     }});
  87
  88     it("handles highs", function () { with (this) {
  89         assertEqual(B, lerp(A, B, 1));
  90         assertEqual(B, lerp(A, B, 2));
  91         assertEqual(B, lerp(A, B, Infinity));
  92     }});
  93
  94     it("edits strings", function () { with (this) {
  95         assertEqual(A, lerp(A, B, 0.01));
  96         assertEqual("I do not like treen eggs and ham?", lerp(A, B, 0.3));
  97         assertEqual("I do not like them, eggs and ham?", lerp(A, B, 0.5));
  98         assertEqual("I do not like them, Sam-Iham?", lerp(A, B, 0.9));
  99         assertEqual(B, lerp(A, B, 0.99));
 100     }});
 101
 102     it("doesn't make half a poo", function () { with (this) {
 103         var poos = "\uD83D\uDCA9\uD83D\uDCA9\uD83D\uDCA9\uD83D\uDCA9";
 104         assertEqual("\uD83D\uDCA9\uD83D\uDCA9", lerp("", poos, 0.5));
 105         assertEqual("\uD83D\uDCA9", lerp("", poos, 0.35));
 106
 107         for (var i = 0; i <= 1; i += 1/256)
 108             assertNot(lerp("", poos, i).match(HALF_POOS));
 109     }});
 110
 111     it("doesn't misplace combining marks", function () { with (this) {
 112         for (var i = 0; i <= 1; i += 1/256) {
 113             var r = lerp("a", UNUSUAL_Q, i);
 114             assert(r === "a" || r === UNUSUAL_Q);
 115         }
 116     }});
 117 }});
 118
 119 JS.Test.describe('numeric lerp', function () { with (this) {
 120     var lerp = m.numericLerp;
 121
 122     it("handles empty strings", function () { with (this) {
 123         assertEqual("", lerp("", "", -1));
 124         assertEqual("", lerp("", "", 0));
 125         assertEqual("", lerp("", "", 0.5));
 126         assertEqual("", lerp("", "", 1));
 127         assertEqual("", lerp("", "", 2));
 128     }});
 129
 130     it("handles single numbers", function () { with (this) {
 131         assertEqual("0", lerp("0", "100", 0));
 132         assertEqual("50", lerp("0", "100", 0.5));
 133         assertEqual("100", lerp("0", "100", 1.0));
 134         assertEqual("150", lerp("0", "100", 1.5));
 135     }});
 136
 137     it("rounds integers", function () { with (this) {
 138         assertEqual("12", lerp("0", "100", 0.123));
 139         assertEqual("12.3", lerp("0", "100.0", 0.123));
 140         assertEqual("12.3", lerp("0.0", "100", 0.123));
 141         assertEqual("12.3", lerp("0.0", "100.0", 0.123));
 142     }});
 143
 144     it("computes parameters outside [0, 1]", function () { with (this) {
 145         assertEqual("Giving 110%", lerp("Giving 0%", "Giving 100%", 1.1));
 146     }});
 147
 148     it("handles multiple numbers", function () { with (this) {
 149         var A = "Chapter 0. The sky was rgb(0, 0, 0)."
 150         var B = "Chapter 10. The sky was rgb(0, 0, 255)."
 151         assertEqual(A, lerp(A, B, 0));
 152         assertEqual(B, lerp(A, B, 1));
 153         assertEqual("Chapter 5. The sky was rgb(0, 0, 128).", lerp(A, B, 0.5));
 154     }});
 155 }});