fix: some corrections re ignoreCase option

.. to make existing tests pass

also added couple tests for ignoreCase option (but it's < 100% coverage still)
+ docs

Author: artemv

README.md

@@ -23,10 +23,16 @@ bower install jsdiff --save
 
     Returns a list of change objects (See below).
 
+    Options
+    * `ignoreCase`: `true` to ignore casing difference. Defaults to `false`.
+
 * `JsDiff.diffWords(oldStr, newStr[, options])` - diffs two blocks of text, comparing word by word, ignoring whitespace.
 
     Returns a list of change objects (See below).
 
+    Options
+    * `ignoreCase`: Same as in `diffChars`.
+
 * `JsDiff.diffWordsWithSpace(oldStr, newStr[, options])` - diffs two blocks of text, comparing word by word, treating whitespace as significant.
 
     Returns a list of change objects (See below).

src/diff/character.js

@@ -1,4 +1,4 @@
 import Diff from './base';
 
 export const characterDiff = new Diff();
-export function diffChars(oldStr, newStr, callback) { return characterDiff.diff(oldStr, newStr, callback); }
+export function diffChars(oldStr, newStr, options) { return characterDiff.diff(oldStr, newStr, options); }

src/diff/json.js

@@ -22,7 +22,7 @@ jsonDiff.castInput = function(value) {
   }, '  ');
 };
 jsonDiff.equals = function(left, right) {
-  return Diff.prototype.equals(left.replace(/,([\r\n])/g, '$1'), right.replace(/,([\r\n])/g, '$1'));
+  return Diff.prototype.equals.call(jsonDiff, left.replace(/,([\r\n])/g, '$1'), right.replace(/,([\r\n])/g, '$1'));
 };
 
 export function diffJson(oldObj, newObj, options) { return jsonDiff.diff(oldObj, newObj, options); }

src/diff/word.js

@@ -25,9 +25,26 @@ const reWhitespace = /\S/;
 
 export const wordDiff = new Diff();
 wordDiff.equals = function(left, right) {
-  return (left === right)
-    || (this.options.ignoreWhitespace && !reWhitespace.test(left) && !reWhitespace.test(right))
-    || (this.options.ignoreCase && left.toLowerCase() === right.toLowerCase());
+  if (left === right) {
+    return true;
+  }
+
+  let ignoreWhitespaceComparator = (left, right) => {
+    return this.options.ignoreWhitespace && !reWhitespace.test(left) && !reWhitespace.test(right);
+  };
+
+  if (this.options.ignoreCase) {
+      left = left.toLowerCase();
+      right = right.toLowerCase();
+      if (left === right) {
+        return true;
+      }
+      if (ignoreWhitespaceComparator(left, right)) {
+        return true;
+      }
+  } else {
+    return ignoreWhitespaceComparator(left, right);
+  }
 };
 wordDiff.tokenize = function(value) {
   let tokens = value.split(/(\s+|\b)/);
@@ -47,10 +64,11 @@ wordDiff.tokenize = function(value) {
   return tokens;
 };
 
-export function diffWords(oldStr, newStr, callback) {
-  let options = generateOptions(callback, {ignoreWhitespace: true});
+export function diffWords(oldStr, newStr, options) {
+  options = generateOptions(options, {ignoreWhitespace: true});
   return wordDiff.diff(oldStr, newStr, options);
 }
-export function diffWordsWithSpace(oldStr, newStr, callback) {
-  return wordDiff.diff(oldStr, newStr, callback);
+
+export function diffWordsWithSpace(oldStr, newStr, options) {
+  return wordDiff.diff(oldStr, newStr, options);
 }

test/diff/character.js

@@ -9,5 +9,17 @@ describe('diff/character', function() {
       const diffResult = diffChars('New Value.', 'New ValueMoreData.');
       expect(convertChangesToXML(diffResult)).to.equal('New Value<ins>MoreData</ins>.');
     });
+
+    describe('case insensitivity', function() {
+      it("is considered when there's no difference", function() {
+        const diffResult = diffChars('New Value.', 'New value.', {ignoreCase: true});
+        expect(convertChangesToXML(diffResult)).to.equal('New value.');
+      });
+
+      it("is considered when there's a difference", function() {
+        const diffResult = diffChars('New Values.', 'New value.', {ignoreCase: true});
+        expect(convertChangesToXML(diffResult)).to.equal('New value<del>s</del>.');
+      });
+    });
   });
 });

test/diff/word.js

@@ -190,5 +190,17 @@ describe('WordDiff', function() {
         done();
       });
     });
+
+    describe('case insensitivity', function() {
+      it("is considered when there's a difference", function() {
+        const diffResult = diffWordsWithSpace('new value', 'New  ValueMoreData', {ignoreCase: true});
+        expect(convertChangesToXML(diffResult)).to.equal('New<del> value</del><ins>  ValueMoreData</ins>');
+      });
+
+      it("is considered when there's no difference", function() {
+        const diffResult = diffWordsWithSpace('new value', 'New Value', {ignoreCase: true});
+        expect(convertChangesToXML(diffResult)).to.equal('New Value');
+      });
+    });
   });
 });