Eliminate recursion from candidatePermutations

tailwindlabs · Feb 4, 2022 · 66d6313 · 66d6313
1 parent 9f23bb3
commit 66d6313
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Showing 2 changed files with 36 additions and 20 deletions.
diff --git a/src/lib/generateRules.js b/src/lib/generateRules.js
@@ -25,33 +25,33 @@ function getClassNameFromSelector(selector) {
 // Example with dynamic classes:
 // ['grid-cols', '[[linename],1fr,auto]']
 // ['grid', 'cols-[[linename],1fr,auto]']
-function* candidatePermutations(candidate, lastIndex = Infinity) {
-  if (lastIndex < 0) {
-    return
-  }
+function* candidatePermutations(candidate) {
+  let lastIndex = Infinity
 
-  let dashIdx
+  while (lastIndex >= 0) {
+    let dashIdx
 
-  if (lastIndex === Infinity && candidate.endsWith(']')) {
-    let bracketIdx = candidate.indexOf('[')
+    if (lastIndex === Infinity && candidate.endsWith(']')) {
+      let bracketIdx = candidate.indexOf('[')
 
-    // If character before `[` isn't a dash or a slash, this isn't a dynamic class
-    // eg. string[]
-    dashIdx = ['-', '/'].includes(candidate[bracketIdx - 1]) ? bracketIdx - 1 : -1
-  } else {
-    dashIdx = candidate.lastIndexOf('-', lastIndex)
-  }
+      // If character before `[` isn't a dash or a slash, this isn't a dynamic class
+      // eg. string[]
+      dashIdx = ['-', '/'].includes(candidate[bracketIdx - 1]) ? bracketIdx - 1 : -1
+    } else {
+      dashIdx = candidate.lastIndexOf('-', lastIndex)
+    }
 
-  if (dashIdx < 0) {
-    return
-  }
+    if (dashIdx < 0) {
+      break
+    }
 
-  let prefix = candidate.slice(0, dashIdx)
-  let modifier = candidate.slice(dashIdx + 1)
+    let prefix = candidate.slice(0, dashIdx)
+    let modifier = candidate.slice(dashIdx + 1)
 
-  yield [prefix, modifier]
+    yield [prefix, modifier]
 
-  yield* candidatePermutations(candidate, dashIdx - 1)
+    lastIndex = dashIdx - 1
+  }
 }
 
 function applyPrefix(matches, context) {

diff --git a/tests/basic-usage.test.js b/tests/basic-usage.test.js
@@ -172,3 +172,19 @@ it('shadows support values without a leading zero', () => {
     `)
   })
 })
+
+it('can scan extremely long classes without crashing', () => {
+  let val = 'cols-' + "-a".repeat(4000)
+  let config = {
+    content: [{ raw: html`<div class="${val}"></div>` }],
+    corePlugins: { preflight: false },
+  }
+
+  let input = css`
+    @tailwind utilities;
+  `
+
+  return run(input, config).then((result) => {
+    expect(result.css).toMatchFormattedCss(css``)
+  })
+})