Allow default style map to be disabled

3 files changed, 21 insertions, 24 deletions

diff --git a/README.md b/README.md
index 135c7bf..d353e26 100644
--- a/README.md
+++ b/README.md
@@ -67,32 +67,19 @@ var options = {
 mammoth.convertToHtml({path: "path/to/document.docx"}, options);
 ```
 
-To more easily support style mappings stored in text files,
-`styleMap` can also be a string.
-Each non-blank line is treated as a separate style mapping:
+User-defined style mappings are used in preference to the default style mappings.
+To stop using the default style mappings altogether,
+set `options.includeDefaultStyleMap` to `false`:
 
 ```javascript
 var options = {
-    styleMap: "p.SectionTitle => h1:fresh\n" +
-        "p.SubSectionTitle => h2:fresh"
-};
-```
-
-To extend the standard style map:
-
-```javascript
-var mammoth = require("mammoth");
-var style = mammoth.style;
-
-var customStyles = [
-    style("p.AsideHeading => div.aside > h2:fresh"),
-    style("p.AsideText => div.aside > p:fresh")
-];
-
-var options = {
-    styleMap: customStyles.concat(mammoth.standardOptions.styleMap)
+    styleMap: [
+        style("p.SectionTitle => h1:fresh"),
+        style("p.SubSectionTitle => h2:fresh")
+    ],
+    includeDefaultStyleMap: false
+    
 };
-mammoth.convertToHtml({path: "path/to/document.docx"}, options);
 ```
 
 ### API
diff --git a/lib/options-reader.js b/lib/options-reader.js
index fa215f4..687eb92 100644
--- a/lib/options-reader.js
+++ b/lib/options-reader.js
@@ -23,14 +23,16 @@ var standardOptions = exports._standardOptions = {
         style("p:ordered-list(4) => ul|ol > li > ul|ol > li > ul|ol > li > ol > li:fresh"),
         style("p:ordered-list(5) => ul|ol > li > ul|ol > li > ul|ol > li > ul|ol > li > ol > li:fresh")
     ],
-    transformDocument: identity
+    transformDocument: identity,
+    includeDefaultStyleMap: true
 };
 
 function readOptions(options) {
     options = options || {};
     var fullOptions = extend(standardOptions, options);
     
-    fullOptions.styleMap = readStyleMap(options).concat(standardOptions.styleMap);
+    fullOptions.styleMap = readStyleMap(options)
+        .concat(fullOptions.includeDefaultStyleMap ? standardOptions.styleMap : []);
     
     return fullOptions;
 }
diff --git a/tests/options-reader.tests.js b/tests/options-reader.tests.js
index 073b3a5..ea2728d 100644
--- a/tests/options-reader.tests.js
+++ b/tests/options-reader.tests.js
@@ -22,6 +22,14 @@ describe('readOptions', function() {
         assert.deepEqual(style("p.SectionTitle => h2"), options.styleMap[0]);
         assert.deepEqual(standardOptions.styleMap, options.styleMap.slice(1));
     });
+    
+    it('custom style mappings are ignored if includeDefaultStyleMap is false', function() {
+        var options = readOptions({
+            styleMap: "p.SectionTitle => h2",
+            includeDefaultStyleMap: false
+        });
+        assert.deepEqual([style("p.SectionTitle => h2")], options.styleMap);
+    });
 });
 
 function last(array) {