1 var JS
= this.JS
|| require('jstest');
2 var m
= require('../string-lerp');
4 JS
.Test
.describe('fast lerp', function () { with (this) {
6 var A
= "Do you like green eggs and ham?";
7 var B
= "I do not like them, Sam-I-am.";
9 it("handles empty strings", function () { with (this) {
10 assertEqual("", lerp("", "", -1));
11 assertEqual("", lerp("", "", 0));
12 assertEqual("", lerp("", "", 0.5));
13 assertEqual("", lerp("", "", 1));
14 assertEqual("", lerp("", "", 2));
17 it("maintains identity", function () { with (this) {
18 for (var i
= -1; i
< 2; i
+= 1/1024) {
19 assertEqual(A
, lerp(A
, A
, i
));
20 assertEqual(B
, lerp(B
, B
, i
));
24 it("handles lows", function () { with (this) {
25 assertEqual(A
, lerp(A
, B
, -Infinity
));
26 assertEqual(A
, lerp(A
, B
, -1));
27 assertEqual(A
, lerp(A
, B
, 0));
30 it("handles highs", function () { with (this) {
31 assertEqual(B
, lerp(A
, B
, 1));
32 assertEqual(B
, lerp(A
, B
, 2));
33 assertEqual(B
, lerp(A
, B
, Infinity
));
36 it("crams strings together", function () { with (this) {
37 assertEqual("I do not ke green eggs and ham?", lerp(A
, B
, 0.3));
38 assertEqual("I do not like tn eggs and ham?", lerp(A
, B
, 0.5));
39 assertEqual("I do not like them, Sam-I-am?", lerp(A
, B
, 0.98));
43 JS
.Test
.describe('diff lerp', function () { with (this) {
44 var lerp
= m
.diffLerp
;
45 var A
= "Do you like green eggs and ham?";
46 var B
= "I do not like them, Sam-I-am.";
48 it("handles empty strings", function () { with (this) {
49 assertEqual("", lerp("", "", -1));
50 assertEqual("", lerp("", "", 0));
51 assertEqual("", lerp("", "", 0.5));
52 assertEqual("", lerp("", "", 1));
53 assertEqual("", lerp("", "", 2));
56 it("maintains identity", function () { with (this) {
57 for (var i
= -1; i
< 2; i
+= 1/1024) {
58 assertEqual(A
, lerp(A
, A
, i
));
59 assertEqual(B
, lerp(B
, B
, i
));
63 it("handles lows", function () { with (this) {
64 assertEqual(A
, lerp(A
, B
, -Infinity
));
65 assertEqual(A
, lerp(A
, B
, -1));
66 assertEqual(A
, lerp(A
, B
, 0));
69 it("handles highs", function () { with (this) {
70 assertEqual(B
, lerp(A
, B
, 1));
71 assertEqual(B
, lerp(A
, B
, 2));
72 assertEqual(B
, lerp(A
, B
, Infinity
));
75 it("edits strings", function () { with (this) {
76 assertEqual("I do not like treen eggs and ham?", lerp(A
, B
, 0.3));
77 assertEqual("I do not like them, Sggs and ham?", lerp(A
, B
, 0.5));
78 assertEqual("I do not like them, Sam-Iham?", lerp(A
, B
, 0.9));
82 JS
.Test
.describe('numeric lerp', function () { with (this) {
83 var lerp
= m
.numericLerp
;
85 it("handles empty strings", function () { with (this) {
86 assertEqual("", lerp("", "", -1));
87 assertEqual("", lerp("", "", 0));
88 assertEqual("", lerp("", "", 0.5));
89 assertEqual("", lerp("", "", 1));
90 assertEqual("", lerp("", "", 2));
93 it("handles single numbers", function () { with (this) {
94 assertEqual("0", lerp("0", "100", 0));
95 assertEqual("50", lerp("0", "100", 0.5));
96 assertEqual("100", lerp("0", "100", 1.0));
97 assertEqual("150", lerp("0", "100", 1.5));
100 it("rounds integers", function () { with (this) {
101 assertEqual("12", lerp("0", "100", 0.123));
102 assertEqual("12.3", lerp("0", "100.0", 0.123));
103 assertEqual("12.3", lerp("0.0", "100", 0.123));
104 assertEqual("12.3", lerp("0.0", "100.0", 0.123));
107 it("computes parameters outside [0, 1]", function () { with (this) {
108 assertEqual("Giving 110%", lerp("Giving 0%", "Giving 100%", 1.1));
111 it("handles multiple numbers", function () { with (this) {
112 var A
= "Chapter 0. The sky was rgb(0, 0, 0)."
113 var B
= "Chapter 10. The sky was rgb(0, 0, 255)."
114 assertEqual(A
, lerp(A
, B
, 0));
115 assertEqual(B
, lerp(A
, B
, 1));
116 assertEqual("Chapter 5. The sky was rgb(0, 0, 128).", lerp(A
, B
, 0.5));