From ee39cafbfa74a373b3da92af1c23582e657f5d20 Mon Sep 17 00:00:00 2001
From: aircwo <arcwo@nhsbsa.nhs.uk>
Date: Thu, 26 Sep 2024 09:33:22 +0100
Subject: [PATCH] chore: add exclude pattern to the class appender (#378)

---
 lib/_javascripts/markdownClassAppender.js     | 45 ++++++++++++++-----
 lib/_libraries/markdown.js                    | 20 ++-------
 .../javascripts/markdownClassAppender.test.js | 26 ++++++++---
 3 files changed, 57 insertions(+), 34 deletions(-)

diff --git a/lib/_javascripts/markdownClassAppender.js b/lib/_javascripts/markdownClassAppender.js
index b003d3b2d..f9d6f25e7 100644
--- a/lib/_javascripts/markdownClassAppender.js
+++ b/lib/_javascripts/markdownClassAppender.js
@@ -1,11 +1,22 @@
-function appendRuleNames(md, tokens = [], appendRules = true) {
-  let ruleNames = Array.from(tokens);
+function appendRuleNames(
+  md,
+  excludeTokens = [],
+  appendRules = true,
+  excludePatterns = [],
+) {
+  let ruleNames = Array.from(excludeTokens);
   if (appendRules) {
-    for (let ruleName in md.renderer.rules) {
-      if (!ruleNames.includes(ruleName)) {
-        ruleNames.push(ruleName);
-      }
-    }
+    Object.keys(md.renderer.rules)
+      .filter(
+        (ruleName) =>
+          !ruleNames.includes(ruleName) &&
+          !excludePatterns.some((pattern) =>
+            typeof pattern === 'string'
+              ? ruleName.includes(pattern)
+              : pattern.test(ruleName),
+          ),
+      )
+      .forEach((ruleName) => ruleNames.push(ruleName));
   }
   return ruleNames;
 }
@@ -27,13 +38,23 @@ function decorate(md, ruleName, cssClass) {
   };
 }
 
-module.exports = (md, tokens = [], appendRules = true, cssClass = 'md') => {
-  //use all tokens unless specified
-  let ruleNames = appendRuleNames(md, tokens, appendRules);
+module.exports = (md, options = {}) => {
+  const {
+    excludeTokens = [],
+    appendRules = true,
+    cssClass = 'md',
+    excludePatterns = [],
+  } = options;
+
+  let ruleNames = appendRuleNames(
+    md,
+    excludeTokens,
+    appendRules,
+    excludePatterns,
+  );
 
   console.log(`configuring CSS class appender for [${ruleNames}]`);
-  for (let i in ruleNames) {
-    let ruleName = ruleNames[i];
+  for (let ruleName of ruleNames) {
     decorate(md, ruleName, cssClass);
   }
 };
diff --git a/lib/_libraries/markdown.js b/lib/_libraries/markdown.js
index b2ec1c043..0a858facd 100644
--- a/lib/_libraries/markdown.js
+++ b/lib/_libraries/markdown.js
@@ -10,21 +10,6 @@ module.exports = (() => {
     typographer: true,
   });
 
-  // Remember the old renderer if overridden, or proxy to the default renderer.
-  let defaultRender =
-    md.renderer.rules.link_open ||
-    function (tokens, idx, options, env, self) {
-      return self.renderToken(tokens, idx, options);
-    };
-
-  md.renderer.rules.p = function (tokens, idx, options, env, self) {
-    // Adds a 'md' CSS class
-    tokens[idx].attrJoin('class', 'md');
-
-    // Pass the token to the default renderer.
-    return defaultRender(tokens, idx, options, env, self);
-  };
-
   md.use(require('markdown-it-abbr'))
     .use(require('markdown-it-attrs'))
     .use(anchor, {
@@ -63,7 +48,10 @@ module.exports = (() => {
         }
       },
     })
-    .use(require('../_javascripts/markdownClassAppender'), ['dl_open']);
+    .use(require('../_javascripts/markdownClassAppender'), {
+      excludeTokens: ['dl_open'],
+      excludePatterns: ['admonition'],
+    });
 
   return md;
 })();
diff --git a/lib/tests/javascripts/markdownClassAppender.test.js b/lib/tests/javascripts/markdownClassAppender.test.js
index 95d5402dc..baa37a656 100644
--- a/lib/tests/javascripts/markdownClassAppender.test.js
+++ b/lib/tests/javascripts/markdownClassAppender.test.js
@@ -2,9 +2,10 @@ const appender = require('../../_javascripts/markdownClassAppender');
 const markdownit = require('markdown-it');
 
 const fixture_h1 = '# heading 1';
+const fixture_admonition = '!!! note\n    This is an admonition.';
 
-function md(tokens, appendRules) {
-  return markdownit().use(appender, tokens, appendRules);
+function md(options = {}) {
+  return markdownit().use(appender, options);
 }
 
 describe('markdownClassAppender', () => {
@@ -19,14 +20,27 @@ describe('markdownClassAppender', () => {
   });
 
   test('should add class to configured tokens', () => {
-    expect(md(['heading_open']).render(fixture_h1)).toEqual(
+    expect(md({ excludeTokens: ['heading_open'] }).render(fixture_h1)).toEqual(
       '<h1 class="md">heading 1</h1>\n',
     );
   });
 
   test('should miss class when default rules excluded', () => {
-    expect(md([], false).render('`javascript`')).toEqual(
-      '<p><code>javascript</code></p>\n',
-    );
+    expect(
+      md({ excludeTokens: [], appendRules: false }).render('`javascript`'),
+    ).toEqual('<p><code>javascript</code></p>\n');
   });
+
+  test.each(['admonition', /^admonition/])(
+    'should exclude patterns specified as types of strings',
+    (excludePattern) => {
+      // given / when
+      const result = md({ excludePatterns: [excludePattern] }).render(
+        fixture_admonition,
+      );
+
+      // then
+      expect(result).not.toContain('md');
+    },
+  );
 });