Document and test ignoreWhiteSpace for createPatch

Author: oBusk

README.md

@@ -72,8 +72,9 @@ npm install diff --save
     * `oldStr` : Original string value
     * `newStr` : New string value
     * `oldHeader` : Additional information to include in the old file header
-    * `newHeader` : Additional information to include in the new file header
-    * `options` : An object with options. Currently, only `context` is supported and describes how many lines of context should be included.
+    * `newHeader` : Additional information to include in the new file header* `options` : An object with options. 
+      - `context` describes how many lines of context should be included.
+      - `ignoreWhitespace`: `true` to ignore leading and trailing whitespace.
 
 * `Diff.createPatch(fileName, oldStr, newStr, oldHeader, newHeader)` - creates a unified diff patch.
 

test/patch/create.js

@@ -631,6 +631,37 @@ describe('patch/create', function() {
       const diffResult = createTwoFilesPatch('foo', 'bar', '', '');
       expect(diffResult).to.equal(expectedResult);
     });
+
+    describe('ignoreWhitespace', function() {
+      it('ignoreWhitespace: false', function() {
+        const expectedResult =
+          'Index: testFileName\n'
+          + '===================================================================\n'
+          + '--- testFileName\n'
+          + '+++ testFileName\n'
+          + '@@ -1,2 +1,2 @@\n'
+          + '-line   \n'
+          + '- line\n'
+          + '\\ No newline at end of file\n'
+          + '+line\n'
+          + '+line\n'
+          + '\\ No newline at end of file\n';
+
+        const diffResult = createPatch('testFileName', 'line   \n\ line', 'line\n\line', undefined, undefined, {ignoreWhitespace: false});
+        expect(diffResult).to.equal(expectedResult);
+      });
+
+      it('ignoreWhitespace: true', function() {
+        const expectedResult =
+          'Index: testFileName\n'
+          + '===================================================================\n'
+          + '--- testFileName\n'
+          + '+++ testFileName\n';
+
+        const diffResult = createPatch('testFileName', 'line   \n\ line', 'line\n\line', undefined, undefined, {ignoreWhitespace: true});
+        expect(diffResult).to.equal(expectedResult);
+      });
+    });
   });
 
   describe('#structuredPatch', function() {