Resolves #63: provides a render option allowing usage of any markdown…

… parser.

lib/index.d.ts

@@ -1,8 +1,14 @@
-import { marked } from 'marked';
-import Metalsmith from 'metalsmith';
+import { marked } from "marked";
+import { Plugin } from "metalsmith";
+export type EngineOptions<T = marked.MarkedOptions> = T;
 
 export default markdown;
-export interface Options {
+export type Render<E> = (source: string, engineOptions: EngineOptions<E>, context: {
+    path: string;
+    key: string;
+}) => string;
+
+export type Options<E = marked.MarkedOptions> = {
     /**
      * - Key names of file metadata to render to HTML - can be nested
      */
@@ -12,11 +18,17 @@ export interface Options {
      */
     wildcard?: boolean;
     /**
-     * Marked markdown [options](https://marked.js.org/using_advanced#options)
+     * - Specify a custom render function with the signature `(source, engineOptions, context) => string`.
+     * `context` is an object with a `path` key containing the current file path, and `key` containing the target key.
+     */
+    render?: Render<E>;
+    /**
+     * Options to pass to the markdown engine (default [marked](https://github.com/markedjs/marked))
      */
-    engineOptions?: marked.MarkedOptions
+    engineOptions?: EngineOptions<E>;
 };
+
 /**
  * A Metalsmith plugin to render markdown files to HTML
  */
-declare function markdown(options?: Options): Metalsmith.Plugin;
+declare function markdown<E = marked.MarkedOptions>(options?: Options<E>): Plugin;

package.json

@@ -55,12 +55,15 @@
     "marked": "^4.2.4"
   },
   "devDependencies": {
+    "@types/markdown-it": "^12.2.3",
+    "@types/marked": "^4.0.8",
     "assert-dir-equal": "^1.1.0",
     "auto-changelog": "^2.4.0",
     "eslint": "^8.30.0",
     "eslint-config-prettier": "^8.5.0",
     "eslint-plugin-import": "^2.26.0",
     "eslint-plugin-n": "^15.6.0",
+    "markdown-it": "^13.0.1",
     "metalsmith": "^2.5.0",
     "microbundle": "^0.15.1",
     "mocha": "^9.2.2",

src/index.js

@@ -4,23 +4,30 @@ import { dset as set } from 'dset'
 import { marked } from 'marked'
 import expandWildcardKeypaths from './expand-wildcard-keypath.js'
 
-function render(data, key, options) {
-  const value = get(data, key)
-  if (typeof value === 'string') {
-    set(data, key, marked(value, options))
-  }
+function defaultRender(source, options) {
+  return marked(source, options)
 }
 
+/**
+ * @callback Render
+ * @param {string} source
+ * @param {Object} engineOptions
+ * @param {{ path: string, key: string}} context
+ */
+
 /**
  * @typedef Options
  * @property {string[]} [keys] - Key names of file metadata to render to HTML - can be nested
  * @property {boolean} [wildcard=false] - Expand `*` wildcards in keypaths
+ * @property {Render} [render] - Specify a custom render function with the signature `(source, engineOptions, context) => string`.
+ * `context` is an object with a `path` key containing the current file path, and `key` containing the target key.
  * @property {Object} [engineOptions] Options to pass to the markdown engine (default [marked](https://github.com/markedjs/marked))
  **/
 
 const defaultOptions = {
   keys: [],
   wildcard: false,
+  render: defaultRender,
   engineOptions: {}
 }
 
@@ -65,16 +72,21 @@ function markdown(options = defaultOptions) {
       if ('.' != dir) html = join(dir, html)
 
       debug.info('Rendering file "%s" as "%s"', file, html)
-      const str = marked(data.contents.toString(), options.engineOptions)
+      const str = options.render(data.contents.toString(), options.engineOptions, { path: file, key: 'contents' })
       data.contents = Buffer.from(str)
 
       let keys = options.keys
       if (options.wildcard) {
         keys = expandWildcardKeypaths(data, options.keys, '*')
       }
-      keys.forEach((k) => {
-        debug.info('Rendering key "%s" of file "%s"', k.join ? k.join('.') : k, file)
-        render(data, k, options.engineOptions)
+      keys.forEach((key) => {
+        const value = get(data, key)
+        if (typeof value === 'string') {
+          debug.info('Rendering key "%s" of file "%s"', key.join ? key.join('.') : key, file)
+          set(data, key, options.render(value, options.engineOptions, { path: file, key }))
+        } else {
+          debug.warn('Couldn\'t render key %s of file "%s": not a string', key.join ? key.join('.') : key, file)
+        }
       })
 
       delete files[file]