client/util: refactor Markdown formatter code

2 files changed, 139 insertions, 64 deletions

diff --git a/client/js/util/markdown.js b/client/js/util/markdown.js
new file mode 100644
index 0000000..3b79c47
--- /dev/null
+++ b/client/js/util/markdown.js
@@ -0,0 +1,137 @@
+'use strict';
+
+const marked = require('marked');
+
+class BaseMarkdownWrapper {
+    preprocess(text) {
+        return text;
+    }
+
+    postprocess(text) {
+        return text;
+    }
+}
+
+class SjisWrapper extends BaseMarkdownWrapper {
+    constructor() {
+        super();
+        this.buf = [];
+    }
+
+    preprocess(text) {
+        return text.replace(
+            /\[sjis\]((?:[^\[]|\[(?!\/?sjis\]))+)\[\/sjis\]/ig,
+            (match, capture) => {
+                var ret = '%%%SJIS' + this.buf.length;
+                this.buf.push(capture);
+                return ret;
+            });
+    }
+
+    postprocess(text) {
+        return text.replace(
+            /(?:<p>)?%%%SJIS(\d+)(?:<\/p>)?/,
+            (match, capture) => {
+                return '<div class="sjis">' + this.buf[capture] + '</div>';
+            });
+    }
+}
+
+// fix \ before ~ being stripped away
+class TildeWrapper extends BaseMarkdownWrapper {
+    preprocess(text) {
+        return text.replace(/\\~/g, '%%%T');
+    }
+
+    postprocess(text) {
+        return text.replace(/%%%T/g, '\\~');
+    }
+}
+
+//prevent ^#... from being treated as headers, due to tag permalinks
+class TagPermalinkFixWrapper extends BaseMarkdownWrapper {
+    preprocess(text) {
+        return text.replace(/^#/g, '%%%#');
+    }
+
+    postprocess(text) {
+        return text.replace(/%%%#/g, '#');
+    }
+}
+
+//post, user and tags permalinks
+class EntityPermalinkWrapper extends BaseMarkdownWrapper {
+    preprocess(text) {
+        text = text.replace(
+            /(^|^\(|(?:[^\]])\(|[\s<>\[\]\)])([+#@][a-zA-Z0-9_-]+)/g,
+            '$1[$2]($2)');
+        text = text.replace(/\]\(@(\d+)\)/g, '](/post/$1)');
+        text = text.replace(/\]\(\+([a-zA-Z0-9_-]+)\)/g, '](/user/$1)');
+        text = text.replace(/\]\(#([a-zA-Z0-9_-]+)\)/g, '](/posts/query=$1)');
+        return text;
+    }
+}
+
+class SearchPermalinkWrapper extends BaseMarkdownWrapper {
+    postprocess(text) {
+        return text.replace(
+            /\[search\]((?:[^\[]|\[(?!\/?search\]))+)\[\/search\]/ig,
+            '<a href="/posts/query=$1"><code>$1</code></a>');
+    }
+}
+
+class SpoilersWrapper extends BaseMarkdownWrapper {
+    postprocess(text) {
+        return text.replace(
+            /\[spoiler\]((?:[^\[]|\[(?!\/?spoiler\]))+)\[\/spoiler\]/ig,
+            '<span class="spoiler">$1</span>');
+    }
+}
+
+class SmallWrapper extends BaseMarkdownWrapper {
+    postprocess(text) {
+        return text.replace(
+            /\[small\]((?:[^\[]|\[(?!\/?small\]))+)\[\/small\]/ig,
+            '<small>$1</small>');
+    }
+}
+
+class StrikeThroughWrapper extends BaseMarkdownWrapper {
+    postprocess(text) {
+        text = text.replace(/(^|[^\\])(~~|~)([^~]+)\2/g, '$1<del>$3</del>');
+        return text.replace(/\\~/g, '~');
+    }
+}
+
+function formatMarkdown(text) {
+    const renderer = new marked.Renderer();
+    const options = {
+        renderer: renderer,
+        breaks: true,
+        sanitize: true,
+        smartypants: true,
+    };
+    let wrappers = [
+        new SjisWrapper(),
+        new TildeWrapper(),
+        new TagPermalinkFixWrapper(),
+        new EntityPermalinkWrapper(),
+        new SearchPermalinkWrapper(),
+        new SpoilersWrapper(),
+        new SmallWrapper(),
+        new StrikeThroughWrapper(),
+    ];
+    for (let wrapper of wrappers) {
+        text = wrapper.preprocess(text);
+    }
+    text = marked(text, options);
+    wrappers.reverse();
+    for (let wrapper of wrappers) {
+        text = wrapper.postprocess(text);
+    }
+    return text;
+}
+
+module.exports = {
+    formatMarkdown: formatMarkdown,
+};
diff --git a/client/js/util/misc.js b/client/js/util/misc.js
index 83e286d..256fae6 100644
--- a/client/js/util/misc.js
+++ b/client/js/util/misc.js
@@ -1,6 +1,6 @@
 'use strict';
 
-const marked = require('marked');
+const markdown = require('./markdown.js');
 
 function decamelize(str, sep) {
     sep = sep === undefined ? '-' : sep;
@@ -92,69 +92,7 @@ function formatRelativeTime(timeString) {
 }
 
 function formatMarkdown(text) {
-    const renderer = new marked.Renderer();
-
-    const options = {
-        renderer: renderer,
-        breaks: true,
-        sanitize: true,
-        smartypants: true,
-    };
-
-    const sjis = [];
-
-    const preDecorator = text => {
-        text = text.replace(
-            /\[sjis\]((?:[^\[]|\[(?!\/?sjis\]))+)\[\/sjis\]/ig,
-            (match, capture) => {
-                var ret = '%%%SJIS' + sjis.length;
-                sjis.push(capture);
-                return ret;
-            });
-        //prevent ^#... from being treated as headers, due to tag permalinks
-        text = text.replace(/^#/g, '%%%#');
-        //fix \ before ~ being stripped away
-        text = text.replace(/\\~/g, '%%%T');
-        //post, user and tags premalinks
-        text = text.replace(
-            /(^|^\(|(?:[^\]])\(|[\s<>\[\]\)])([+#@][a-zA-Z0-9_-]+)/g,
-            '$1[$2]($2)');
-        text = text.replace(/\]\(@(\d+)\)/g, '](/post/$1)');
-        text = text.replace(/\]\(\+([a-zA-Z0-9_-]+)\)/g, '](/user/$1)');
-        text = text.replace(/\]\(#([a-zA-Z0-9_-]+)\)/g, '](/posts/query=$1)');
-        return text;
-    };
-
-    const postDecorator = text => {
-        //restore fixes
-        text = text.replace(/%%%T/g, '\\~');
-        text = text.replace(/%%%#/g, '#');
-
-        text = text.replace(
-            /(?:<p>)?%%%SJIS(\d+)(?:<\/p>)?/,
-            (match, capture) => {
-                return '<div class="sjis">' + sjis[capture] + '</div>';
-            });
-
-        //search permalinks
-        text = text.replace(
-            /\[search\]((?:[^\[]|\[(?!\/?search\]))+)\[\/search\]/ig,
-            '<a href="/posts/query=$1"><code>$1</code></a>');
-        //spoilers
-        text = text.replace(
-            /\[spoiler\]((?:[^\[]|\[(?!\/?spoiler\]))+)\[\/spoiler\]/ig,
-            '<span class="spoiler">$1</span>');
-        //[small]
-        text = text.replace(
-            /\[small\]((?:[^\[]|\[(?!\/?small\]))+)\[\/small\]/ig,
-            '<small>$1</small>');
-        //strike-through
-        text = text.replace(/(^|[^\\])(~~|~)([^~]+)\2/g, '$1<del>$3</del>');
-        text = text.replace(/\\~/g, '~');
-        return text;
-    };
-
-    return postDecorator(marked(preDecorator(text), options));
+    return markdown.formatMarkdown(text);
 }
 
 function formatUrlParameters(dict) {