From 99d8cc1d0b158d1fb2e992996e7fabf2ec3751a3 Mon Sep 17 00:00:00 2001
From: Sukka <isukkaw@gmail.com>
Date: Tue, 26 Apr 2022 11:22:03 +0800
Subject: [PATCH] refactor(prism): support alias (#274)

---
 lib/prism.js       | 18 ++++++++++++++++--
 test/prism.spec.js | 32 +++++++++++++++++++++++++-------
 2 files changed, 41 insertions(+), 9 deletions(-)

diff --git a/lib/prism.js b/lib/prism.js
index c6ed45ce..3a5f04d0 100644
--- a/lib/prism.js
+++ b/lib/prism.js
@@ -6,7 +6,19 @@ const prismLoadLanguages = require('prismjs/components/');
 
 // https://github.com/PrismJS/prism/issues/2145
 const prismComponents = require('prismjs/components');
-const prismSupportedLanguages = Object.keys(prismComponents.languages);
+
+const prismAlias = Object.entries(prismComponents.languages).reduce((acc, [key, value]) => {
+  if (value.alias) {
+    if (Array.isArray(value.alias)) {
+      value.alias.forEach(alias => (acc[alias] = key));
+    } else if (typeof value.alias === 'string') {
+      acc[value.alias] = key;
+    }
+  }
+  return acc;
+}, {});
+
+const prismSupportedLanguages = Object.keys(prismComponents.languages).concat(Object.keys(prismAlias));
 
 const escapeHTML = require('./escape_html');
 
@@ -59,7 +71,9 @@ function PrismUtil(str, options = {}) {
   } = options;
 
   // To be consistent with highlight.js
-  const language = lang === 'plaintext' || lang === 'none' ? 'none' : lang;
+  let language = lang === 'plaintext' || lang === 'none' ? 'none' : lang;
+
+  if (prismAlias[language]) language = prismAlias[language];
 
   const preTagClassArr = [];
   const preTagAttrArr = [];
diff --git a/test/prism.spec.js b/test/prism.spec.js
index 32055a76..324e2fb6 100644
--- a/test/prism.spec.js
+++ b/test/prism.spec.js
@@ -109,8 +109,8 @@ describe('prismHighlight', () => {
     const result = prismHighlight(input, { lang: 'js' });
 
     // Start Tag
-    result.should.contains('<pre class="line-numbers language-js" data-language="js">');
-    result.should.contains('<code class="language-js');
+    result.should.contains('<pre class="line-numbers language-javascript" data-language="javascript">');
+    result.should.contains('<code class="language-javascript');
     // End Tag
     result.should.contains(endTag);
     // Line Number
@@ -139,6 +139,24 @@ describe('prismHighlight', () => {
     validateHtmlAsync(result, done);
   });
 
+  it('language - ts (an alias for typescript)', done => {
+    const input = 'const a: string = "";';
+
+    const result = prismHighlight(input, { lang: 'ts' });
+
+    // Start Tag
+    result.should.contains('<pre class="line-numbers language-typescript" data-language="typescript">');
+    result.should.contains('<code class="language-typescript');
+    // End Tag
+    result.should.contains(endTag);
+    // Line Number
+    result.should.contains(lineNumberStartTag);
+    // Being highlighted
+    result.should.contains(highlightToken);
+
+    validateHtmlAsync(result, done);
+  });
+
   it('language - unsupported by prism', done => {
     const input = `
       [ yet another pi calculation program in bf
@@ -206,8 +224,8 @@ describe('prismHighlight', () => {
     const result = prismHighlight(input, { lang: 'js', isPreprocess: false });
 
     // Start Tag
-    result.should.contains('<pre class="line-numbers language-js" data-language="js">');
-    result.should.contains('<code class="language-js');
+    result.should.contains('<pre class="line-numbers language-javascript" data-language="javascript">');
+    result.should.contains('<code class="language-javascript');
     // End Tag
     result.should.contains(endTag);
     // Line Number
@@ -267,15 +285,15 @@ describe('prismHighlight', () => {
     ].join('\n');
 
     const result1 = prismHighlight(input, { lang: 'js', isPreprocess: false, lineNumber: true, firstLine: '-5' });
-    result1.should.contains('<pre class="line-numbers language-js" data-language="js" data-start="-5">');
+    result1.should.contains('<pre class="line-numbers language-javascript" data-language="javascript" data-start="-5">');
 
     // isPreprocess - true (firstLine should be disabled)
     const result2 = prismHighlight(input, { lang: 'js', isPreprocess: true, lineNumber: true, firstLine: '-5' });
-    result2.should.contains('<pre class="line-numbers language-js" data-language="js">');
+    result2.should.contains('<pre class="line-numbers language-javascript" data-language="javascript">');
 
     // lineNumber - false (firstLine should be disabled)
     const result3 = prismHighlight(input, { lang: 'js', isPreprocess: false, lineNumber: false, firstLine: '-5' });
-    result3.should.contains('<pre class="language-js" data-language="js">');
+    result3.should.contains('<pre class="language-javascript" data-language="javascript">');
 
     // Only validate the result1
     validateHtmlAsync(result1, done);