Ignore regex literals when analyzing language boundaries

packages/tailwindcss-language-server/tests/env/v4.test.js

@@ -791,3 +791,51 @@ defineTest({
     })
   },
 })
+
+defineTest({
+  options: { only: true },
+  name: 'regex literals do not break language boundaries',
+  fs: {
+    'app.css': css`
+      @import 'tailwindcss';
+    `,
+  },
+  prepare: async ({ root }) => ({ client: await createClient({ root }) }),
+  handle: async ({ client }) => {
+    let doc = await client.open({
+      lang: 'javascriptreact',
+      text: js`
+        export default function Page() {
+          let styles = "str".match(/<style>[\s\S]*?<\/style>/m)
+          return <div className="bg-[#000]">{styles}</div>
+        }
+      `,
+    })
+
+    expect(await client.project()).toMatchObject({
+      tailwind: {
+        version: '4.0.6',
+        isDefaultVersion: true,
+      },
+    })
+
+    //   return <div className="bg-[#000]">{styles}</div>
+    //                          ^
+    let hover = await doc.hover({ line: 2, character: 26 })
+
+    expect(hover).toEqual({
+      contents: {
+        language: 'css',
+        value: dedent`
+          .bg-\[\#000\] {
+            background-color: #000;
+          }
+        `,
+      },
+      range: {
+        start: { line: 2, character: 25 },
+        end: { line: 2, character: 34 },
+      },
+    })
+  },
+})

packages/tailwindcss-language-service/src/util/doc.ts

@@ -127,5 +127,155 @@ function getJsWithoutComments(text: string): string {
     }
   }
 
+  str = stripRegexLiterals(str)
+
   return str
 }
+
+function stripRegexLiterals(input: string) {
+  const BACKSLASH = 0x5c // \
+  const SLASH = 0x2f // /
+  const LINE_BREAK = 0x0a // \n
+  const COMMA = 0x2c // ,
+  const COLON = 0x3a // :
+  const EQUALS = 0x3d // =
+  const SEMICOLON = 0x3b // ;
+  const BRACKET_OPEN = 0x5b // [
+  const BRACKET_CLOSE = 0x5d // ]
+  const QUESTION_MARK = 0x3f // ?
+  const PAREN_OPEN = 0x28 // (
+  const CURLY_OPEN = 0x7b // {
+  const DOUBLE_QUOTE = 0x22 // "
+  const SINGLE_QUOTE = 0x27 // '
+  const BACKTICK = 0x60 // `
+
+  let SPACE = 0x20 // " "
+  let TAB = 0x09 // \t
+
+  // Top level; or
+  // after comma
+  // after colon
+  // after equals
+  // after semicolon
+  // after square bracket (arrays, object property expressions)
+  // after question mark
+  // after open paren
+  // after curly (jsx only)
+
+  let inRegex = false
+  let inEscape = false
+  let inCharacterClass = false
+
+  let regexStart = -1
+  let regexEnd = -1
+
+  // Based on the oxc_parser crate
+  // https://github.com/oxc-project/oxc/blob/5f97f28ddbd2cd303a306f7fb0092b0e54bda43c/crates/oxc_parser/src/lexer/regex.rs#L29
+  let prev = null
+  for (let i = 0; i < input.length; ++i) {
+    let c = input.charCodeAt(i)
+
+    if (inRegex) {
+      if (c === LINE_BREAK) {
+        break
+      } else if (inEscape) {
+        inEscape = false
+      } else if (c === SLASH && !inCharacterClass) {
+        inRegex = false
+        regexEnd = i
+        break
+      } else if (c === BRACKET_OPEN) {
+        inCharacterClass = true
+      } else if (c === BACKSLASH) {
+        inEscape = true
+      } else if (c === BRACKET_CLOSE) {
+        inCharacterClass = false
+      }
+
+      continue
+    }
+
+    // Skip over strings
+    if (c === SINGLE_QUOTE) {
+      for (let j = i; j < input.length; ++j) {
+        let peekChar = input.charCodeAt(j)
+
+        if (peekChar === BACKSLASH) {
+          j += 1
+        } else if (peekChar === SINGLE_QUOTE) {
+          i = j
+          break
+        } else if (peekChar === LINE_BREAK) {
+          i = j
+          break
+        }
+      }
+    }
+    //
+    else if (c === DOUBLE_QUOTE) {
+      for (let j = i; j < input.length; ++j) {
+        let peekChar = input.charCodeAt(j)
+
+        if (peekChar === BACKSLASH) {
+          j += 1
+        } else if (peekChar === DOUBLE_QUOTE) {
+          i = j
+          break
+        } else if (peekChar === LINE_BREAK) {
+          i = j
+          break
+        }
+      }
+    }
+    //
+    else if (c === BACKTICK) {
+      for (let j = i; j < input.length; ++j) {
+        let peekChar = input.charCodeAt(j)
+
+        if (peekChar === BACKSLASH) {
+          j += 1
+        } else if (peekChar === BACKTICK) {
+          i = j
+          break
+        } else if (peekChar === LINE_BREAK) {
+          i = j
+          break
+        }
+      }
+    }
+    //
+    else if (c === SPACE || c === TAB) {
+      // do nothing
+    }
+    //
+    else if (c === SLASH) {
+      if (
+        prev === COMMA ||
+        prev === COLON ||
+        prev === EQUALS ||
+        prev === SEMICOLON ||
+        prev === BRACKET_OPEN ||
+        prev === QUESTION_MARK ||
+        prev === PAREN_OPEN ||
+        prev === CURLY_OPEN ||
+        prev === LINE_BREAK
+      ) {
+        inRegex = true
+        regexStart = i
+      }
+    }
+    //
+    else {
+      prev = c
+    }
+  }
+
+  // Unterminated regex literal
+  if (inRegex) return input
+
+  if (regexStart === -1 || regexEnd === -1) return input
+
+  return (
+    input.slice(0, regexStart) + ' '.repeat(regexEnd - regexStart + 1) + input.slice(regexEnd + 1)
+  )
+}

packages/tailwindcss-language-service/src/util/find.test.ts

@@ -1,12 +1,6 @@
-import { createState, getDefaultTailwindSettings, Settings, type DocumentClassList } from './state'
 import { test } from 'vitest'
-import { TextDocument } from 'vscode-languageserver-textdocument'
 import { findClassListsInHtmlRange } from './find'
-import type { DeepPartial } from '../types'
-import dedent from 'dedent'
-
-const js = dedent
-const html = dedent
+import { js, html, createDocument } from './test-utils'
 
 test('class regex works in astro', async ({ expect }) => {
   let file = createDocument({
@@ -688,56 +682,3 @@ test('classFunctions should only match in JS-like contexts', async ({ expect })
     },
   ])
 })
-
-function createDocument({
-  name,
-  lang,
-  content,
-  settings,
-}: {
-  name: string
-  lang: string
-  content: string | string[]
-  settings: DeepPartial<Settings>
-}) {
-  let doc = TextDocument.create(
-    `file://${name}`,
-    lang,
-    1,
-    typeof content === 'string' ? content : content.join('\n'),
-  )
-  let defaults = getDefaultTailwindSettings()
-  let state = createState({
-    editor: {
-      getConfiguration: async () => ({
-        ...defaults,
-        ...settings,
-        tailwindCSS: {
-          ...defaults.tailwindCSS,
-          ...settings.tailwindCSS,
-          lint: {
-            ...defaults.tailwindCSS.lint,
-            ...(settings.tailwindCSS?.lint ?? {}),
-          },
-          experimental: {
-            ...defaults.tailwindCSS.experimental,
-            ...(settings.tailwindCSS?.experimental ?? {}),
-          },
-          files: {
-            ...defaults.tailwindCSS.files,
-            ...(settings.tailwindCSS?.files ?? {}),
-          },
-        },
-        editor: {
-          ...defaults.editor,
-          ...settings.editor,
-        },
-      }),
-    },
-  })
-
-  return {
-    doc,
-    state,
-  }
-}