feat(highlight): add an option to switch stripIndent (#398)

* feat(highlight): provide an option to disable stripIndent

* feat(highlight): add an option to switch stripIndent

* update docs

README.md

@@ -289,6 +289,7 @@ Option | Description | Default
 `autoDetect` | Detect language automatically (warning: slow)<br>_Sublanguage highlight requires `autoDetect` to be enabled and `lang` to be unset_  | false
 `mark` | Line highlight specific line(s) |
 `languageAttr` | Output code language into `data-language` attr | false
+`stripIndent`| Whether to strip leading whitespace via [strip-indent](https://www.npmjs.com/package/strip-indent) | true
 
 ### htmlTag(tag, attrs, text, escape)
 
@@ -451,6 +452,8 @@ Option | Description | Default
 `mark` | Highlight specific line |
 `firstLine` | First line number |
 `caption` | Caption |
+`stripIndent`| Whether to strip leading whitespace via [strip-indent](https://www.npmjs.com/package/strip-indent) | true
+
 
 When `isPreprocess` is enabled, `prismHighlight()` will return PrismJS processed HTML snippet. Otherwise `str` will only be escaped and `prismHighlight()` will return the HTML snippet that is suitable for `prism.js` working in the Browser.
 

lib/highlight.ts

@@ -16,11 +16,11 @@ interface Options {
   mark?: number[];
   tab?: string;
   wrap?: boolean;
+  stripIndent?: boolean;
 }
 
 function highlightUtil(str: string, options: Options = {}) {
   if (typeof str !== 'string') throw new TypeError('str must be a string!');
-  str = stripIndent(str);
 
   const useHljs = Object.prototype.hasOwnProperty.call(options, 'hljs') ? options.hljs : false;
   const {
@@ -29,10 +29,15 @@ function highlightUtil(str: string, options: Options = {}) {
     caption,
     mark = [],
     languageAttr = false,
-    tab
+    tab,
+    stripIndent: enableStripIndent = true
   } = options;
   let { wrap = true } = options;
 
+  if (enableStripIndent) {
+    str = stripIndent(str);
+  }
+
   if (!hljs) {
     hljs = require('highlight.js');
   }

lib/prism.ts

@@ -65,11 +65,11 @@ interface Options {
   lineNumber?: boolean;
   mark?: string;
   tab?: string;
+  stripIndent?: boolean;
 }
 
 function PrismUtil(str: string, options: Options = {}) {
   if (typeof str !== 'string') throw new TypeError('str must be a string!');
-  str = stripIndent(str);
 
   const {
     lineNumber = true,
@@ -78,9 +78,14 @@ function PrismUtil(str: string, options: Options = {}) {
     mark,
     firstLine,
     isPreprocess = true,
-    caption
+    caption,
+    stripIndent: enableStripIndent = true
   } = options;
 
+  if (enableStripIndent) {
+    str = stripIndent(str);
+  }
+
   // To be consistent with highlight.js
   let language = lang === 'plaintext' || lang === 'none' ? 'none' : lang;