From 0664aae901b7b162c3b030276c78d8c2f086ead6 Mon Sep 17 00:00:00 2001
From: Jordan Pittman <jordan@cryptica.me>
Date: Thu, 9 Jun 2022 16:53:02 -0400
Subject: [PATCH] Fix class detection in markdown code fences and slim
 templates (#8569)

* Fix detection of classes in markdown code fences

* Fix candidate detection in `.slim` templates

* Update changelog
---
 CHANGELOG.md                    |  1 +
 src/lib/defaultExtractor.js     | 14 +++++++-------
 tests/default-extractor.test.js | 27 +++++++++++++++++++++++----
 3 files changed, 31 insertions(+), 11 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 15dd1f44146e..279413af424e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -12,6 +12,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Fix candidate extractor regression ([#8558](https://github.com/tailwindlabs/tailwindcss/pull/8558))
 - Split `::backdrop`` into separate defaults group ([#8567](https://github.com/tailwindlabs/tailwindcss/pull/8567))
 - Fix postcss plugin type ([#8564](https://github.com/tailwindlabs/tailwindcss/pull/8564))
+- Fix class detection in markdown code fences and slim templates ([#8569](https://github.com/tailwindlabs/tailwindcss/pull/8569))
 
 ## [3.1.0] - 2022-06-08
 
diff --git a/src/lib/defaultExtractor.js b/src/lib/defaultExtractor.js
index 98bc7386baca..c3e5b642cc3f 100644
--- a/src/lib/defaultExtractor.js
+++ b/src/lib/defaultExtractor.js
@@ -25,7 +25,7 @@ function* buildRegExps(context) {
 
   let utility = regex.any([
     // Arbitrary properties
-    /\[[^\s:'"]+:[^\s\]]+\]/,
+    /\[[^\s:'"`]+:[^\s\]]+\]/,
 
     // Utilities
     regex.pattern([
@@ -43,7 +43,7 @@ function* buildRegExps(context) {
             /(?![{([]])/,
 
             // optionally followed by an opacity modifier
-            /(?:\/[^\s'"\\><$]*)?/,
+            /(?:\/[^\s'"`\\><$]*)?/,
           ]),
 
           regex.pattern([
@@ -54,11 +54,11 @@ function* buildRegExps(context) {
             /(?![{([]])/,
 
             // optionally followed by an opacity modifier
-            /(?:\/[^\s'"\\$]*)?/,
+            /(?:\/[^\s'"`\\$]*)?/,
           ]),
 
           // Normal values w/o quotes — may include an opacity modifier
-          /[-\/][^\s'"\\$={><]*/,
+          /[-\/][^\s'"`\\$={><]*/,
         ])
       ),
     ]),
@@ -69,8 +69,8 @@ function* buildRegExps(context) {
     '((?=((',
     regex.any(
       [
-        regex.pattern([/([^\s"'\[\\]+-)?\[[^\s"'\\]+\]/, separator]),
-        regex.pattern([/[^\s"'\[\\]+/, separator]),
+        regex.pattern([/([^\s"'`\[\\]+-)?\[[^\s"'`\\]+\]/, separator]),
+        regex.pattern([/[^\s"'`\[\\]+/, separator]),
       ],
       true
     ),
@@ -91,7 +91,7 @@ function* buildRegExps(context) {
   ])
 
   // 5. Inner matches
-  // yield /[^<>"'`\s.(){}[\]#=%$]*[^<>"'`\s.(){}[\]#=%:$]/g
+  yield /[^<>"'`\s.(){}[\]#=%$]*[^<>"'`\s.(){}[\]#=%:$]/g
 }
 
 // We want to capture any "special" characters
diff --git a/tests/default-extractor.test.js b/tests/default-extractor.test.js
index 4e1792e8e7b9..75abf4caebfd 100644
--- a/tests/default-extractor.test.js
+++ b/tests/default-extractor.test.js
@@ -415,28 +415,24 @@ test('with single quotes array within template literal', async () => {
   const extractions = defaultExtractor(`<div class=\`\${['pr-1.5']}\`></div>`)
 
   expect(extractions).toContain('pr-1.5')
-  expect(extractions).not.toContain('pr-1')
 })
 
 test('with double quotes array within template literal', async () => {
   const extractions = defaultExtractor(`<div class=\`\${["pr-1.5"]}\`></div>`)
 
   expect(extractions).toContain('pr-1.5')
-  expect(extractions).not.toContain('pr-1')
 })
 
 test('with single quotes array within function', async () => {
   const extractions = defaultExtractor(`document.body.classList.add(['pl-1.5'].join(" "));`)
 
   expect(extractions).toContain('pl-1.5')
-  expect(extractions).not.toContain('pl-1')
 })
 
 test('with double quotes array within function', async () => {
   const extractions = defaultExtractor(`document.body.classList.add(["pl-1.5"].join(" "));`)
 
   expect(extractions).toContain('pl-1.5')
-  expect(extractions).not.toContain('pl-1')
 })
 
 test('with angle brackets', async () => {
@@ -449,3 +445,26 @@ test('with angle brackets', async () => {
   expect(extractions).not.toContain('>shadow-xl')
   expect(extractions).not.toContain('shadow-xl<')
 })
+
+test('markdown code fences', async () => {
+  const extractions = defaultExtractor('<!-- this should work: `.font-bold`, `.font-normal` -->')
+
+  expect(extractions).toContain('font-bold')
+  expect(extractions).toContain('font-normal')
+  expect(extractions).not.toContain('.font-bold')
+  expect(extractions).not.toContain('.font-normal')
+})
+
+test('classes in slim templates', async () => {
+  const extractions = defaultExtractor(`
+    p.bg-red-500.text-sm
+      'This is a paragraph
+        small.italic.text-gray-500
+          '(Look mom, no closing tag!)
+  `)
+
+  expect(extractions).toContain('bg-red-500')
+  expect(extractions).toContain('text-sm')
+  expect(extractions).toContain('italic')
+  expect(extractions).toContain('text-gray-500')
+})