Share common lerp requirement checks.

diff --git a/tests/string-lerp.js b/tests/string-lerp.js
index f2fb88d..04fc444 100644 (file)
--- a/tests/string-lerp.js
+++ b/tests/string-lerp.js
@@ -1,14 +1,12 @@
 var JS = this.JS || require('jstest');
-var m = require('../string-lerp');
+var stringLerp = require('../string-lerp');
 
 var HALF_POOS = /\uD83D\uD83D|\uDCA9\uDCA9|\uD83D$/;
 var UNUSUAL_Q = 'q\u0307\u0323';
+var A = "Do you like green eggs and ham?";
+var B = "I do not like them, Sam-I-am.";
 
-JS.Test.describe('fast lerp', function () { with (this) {
-    var lerp = m.fastLerp;
-    var A = "Do you like green eggs and ham?";
-    var B = "I do not like them, Sam-I-am.";
-
+function itHandlesBaseCases (parent, lerp) { with (parent) {
     it("handles empty strings", function () { with (this) {
         assertEqual("", lerp("", "", -1));
         assertEqual("", lerp("", "", 0));
@@ -23,25 +21,9 @@ JS.Test.describe('fast lerp', function () { with (this) {
             assertEqual(B, lerp(B, B, i));
         }
     }});
+}}
 
-    it("handles lows", function () { with (this) {
-        assertEqual(A, lerp(A, B, -Infinity));
-        assertEqual(A, lerp(A, B, -1));
-        assertEqual(A, lerp(A, B, 0));
-    }});
-
-    it("handles highs", function () { with (this) {
-        assertEqual(B, lerp(A, B, 1));
-        assertEqual(B, lerp(A, B, 2));
-        assertEqual(B, lerp(A, B, Infinity));
-    }});
-
-    it("crams strings together", function () { with (this) {
-        assertEqual("I do not ke green eggs and ham?", lerp(A, B, 0.3));
-        assertEqual("I do not like tn eggs and ham?", lerp(A, B, 0.5));
-        assertEqual("I do not like them, Sam-I-am?", lerp(A, B, 0.98));
-    }});
-
+function itMakesValidStrings (parent, lerp) { with (parent) {
     it("doesn't make half a poo", function () { with (this) {
         var poos = "\uD83D\uDCA9\uD83D\uDCA9\uD83D\uDCA9\uD83D\uDCA9";
         assertEqual("\uD83D\uDCA9\uD83D\uDCA9", lerp("", poos, 0.5));
@@ -57,28 +39,9 @@ JS.Test.describe('fast lerp', function () { with (this) {
             assert(r === "a" || r === UNUSUAL_Q);
         }
     }});
-}});
-
-JS.Test.describe('diff lerp', function () { with (this) {
-    var lerp = m.diffLerp;
-    var A = "Do you like green eggs and ham?";
-    var B = "I do not like them, Sam-I-am.";
-
-    it("handles empty strings", function () { with (this) {
-        assertEqual("", lerp("", "", -1));
-        assertEqual("", lerp("", "", 0));
-        assertEqual("", lerp("", "", 0.5));
-        assertEqual("", lerp("", "", 1));
-        assertEqual("", lerp("", "", 2));
-    }});
-
-    it("maintains identity", function () { with (this) {
-        for (var i = -1; i < 2; i += 1/1024) {
-            assertEqual(A, lerp(A, A, i));
-            assertEqual(B, lerp(B, B, i));
-        }
-    }});
+}}
 
+function itDoesntOvershoot (parent, lerp) { with (parent) {
     it("handles lows", function () { with (this) {
         assertEqual(A, lerp(A, B, -Infinity));
         assertEqual(A, lerp(A, B, -1));
@@ -90,7 +53,24 @@ JS.Test.describe('diff lerp', function () { with (this) {
         assertEqual(B, lerp(A, B, 2));
         assertEqual(B, lerp(A, B, Infinity));
     }});
+}}
+
+JS.Test.describe('fast lerp', function () { with (this) {
+    var lerp = stringLerp.fastLerp;
+
+    itHandlesBaseCases(this, lerp);
+    itMakesValidStrings(this, lerp);
+    itDoesntOvershoot(this, lerp);
+
+    it("crams strings together", function () { with (this) {
+        assertEqual("I do not ke green eggs and ham?", lerp(A, B, 0.3));
+        assertEqual("I do not like tn eggs and ham?", lerp(A, B, 0.5));
+        assertEqual("I do not like them, Sam-I-am?", lerp(A, B, 0.98));
+    }});
+
+}});
 
+function itEditsHumanly(parent, lerp) { with (parent) {
     it("edits strings", function () { with (this) {
         assertEqual(A, lerp(A, B, 0.01));
         assertEqual("I do not like treen eggs and ham?", lerp(A, B, 0.3));
@@ -99,22 +79,6 @@ JS.Test.describe('diff lerp', function () { with (this) {
         assertEqual(B, lerp(A, B, 0.99));
     }});
 
-    it("doesn't make half a poo", function () { with (this) {
-        var poos = "\uD83D\uDCA9\uD83D\uDCA9\uD83D\uDCA9\uD83D\uDCA9";
-        assertEqual("\uD83D\uDCA9\uD83D\uDCA9", lerp("", poos, 0.5));
-        assertEqual("\uD83D\uDCA9", lerp("", poos, 0.35));
-
-        for (var i = 0; i <= 1; i += 1/256)
-            assertNot(lerp("", poos, i).match(HALF_POOS));
-    }});
-
-    it("doesn't misplace combining marks", function () { with (this) {
-        for (var i = 0; i <= 1; i += 1/256) {
-            var r = lerp("a", UNUSUAL_Q, i);
-            assert(r === "a" || r === UNUSUAL_Q);
-        }
-    }});
-
     it("prefers ins/del to sub/sub", function () { with (this) {
         // When the cost is uniform this string can be transformed by
         // rewriting the whole thing for the same cost as deleting the
@@ -130,19 +94,18 @@ JS.Test.describe('diff lerp', function () { with (this) {
         // costs.
         assertEqual("core", lerp("apple core", "core dump", 0.51));
     }});
-}});
+}}
 
-JS.Test.describe('numeric lerp', function () { with (this) {
-    var lerp = m.numericLerp;
+JS.Test.describe('diff lerp', function () { with (this) {
+    var lerp = stringLerp.diffLerp;
 
-    it("handles empty strings", function () { with (this) {
-        assertEqual("", lerp("", "", -1));
-        assertEqual("", lerp("", "", 0));
-        assertEqual("", lerp("", "", 0.5));
-        assertEqual("", lerp("", "", 1));
-        assertEqual("", lerp("", "", 2));
-    }});
+    itHandlesBaseCases(this, lerp);
+    itMakesValidStrings(this, lerp);
+    itDoesntOvershoot(this, lerp);
+    itEditsHumanly(this, lerp);
+}});
 
+function itTreatsNumeralsAsNumbers(parent, lerp) { with (parent) {
     it("handles single numbers", function () { with (this) {
         assertEqual("0", lerp("0", "100", 0));
         assertEqual("50", lerp("0", "100", 0.5));
@@ -167,43 +130,27 @@ JS.Test.describe('numeric lerp', function () { with (this) {
     }});
 
     it("handles multiple numbers", function () { with (this) {
-        var A = "Chapter 0. The sky was rgb(0, 0, 0)."
-        var B = "Chapter 10. The sky was rgb(0, 0, 255)."
+        var A = "Chapter 0. The sky was rgb(0, 0, 0).";
+        var B = "Chapter 10. The sky was rgb(0, 0, 255).";
         assertEqual(A, lerp(A, B, 0));
         assertEqual(B, lerp(A, B, 1));
         assertEqual("Chapter 5. The sky was rgb(0, 0, 128).", lerp(A, B, 0.5));
     }});
-}});
-
-JS.Test.describe('fast lerp', function () { with (this) {
-    var lerp = m.lerp;
-    var A = "Do you like green eggs and ham?";
-    var B = "I do not like them, Sam-I-am.";
+}}
 
-    it("handles empty strings", function () { with (this) {
-        assertEqual("", lerp("", "", -1));
-        assertEqual("", lerp("", "", 0));
-        assertEqual("", lerp("", "", 0.5));
-        assertEqual("", lerp("", "", 1));
-        assertEqual("", lerp("", "", 2));
-    }});
+JS.Test.describe('numeric lerp', function () { with (this) {
+    var lerp = stringLerp.numericLerp;
 
-    it("maintains identity", function () { with (this) {
-        for (var i = -1; i < 2; i += 1/1024) {
-            assertEqual(A, lerp(A, A, i));
-            assertEqual(B, lerp(B, B, i));
-        }
-    }});
+    itHandlesBaseCases(this, lerp);
+    itTreatsNumeralsAsNumbers(this, lerp);
+}});
 
-    it("handles lows", function () { with (this) {
-        assertEqual(A, lerp(A, B, -Infinity));
-        assertEqual(A, lerp(A, B, -1));
-        assertEqual(A, lerp(A, B, 0));
-    }});
+JS.Test.describe('auto lerp', function () { with (this) {
+    var lerp = stringLerp.lerp;
 
-    it("handles highs", function () { with (this) {
-        assertEqual(B, lerp(A, B, 1));
-        assertEqual(B, lerp(A, B, 2));
-        assertEqual(B, lerp(A, B, Infinity));
-    }});
+    itHandlesBaseCases(this, lerp);
+    itMakesValidStrings(this, lerp);
+    itDoesntOvershoot(this, lerp);
+    itTreatsNumeralsAsNumbers(this, lerp);
+    itEditsHumanly(this, lerp);
 }});