From af6598aa95f915f74f8a2a9d4fd787d8b0e698ed Mon Sep 17 00:00:00 2001 From: Lauren Tan Date: Wed, 17 Sep 2025 11:48:56 -0400 Subject: [PATCH] Add local eslint rule to validate markdown codeblocks with React Compiler MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit In https://github.com/facebook/react/pull/34462 for example, we found an issue where the compiler was incorrectly validating an example straight from the docs. In order to find more issues like this + also provide more feedback to doc authors on valid/invalid patterns, this PR adds a new local eslint rule which validates all markdown codeblocks containing components/hooks with React Compiler. An autofixer is also provided. To express that a codeblock has an expected error, we can use the following metadata: ```ts // pseudo type def type MarkdownCodeBlockMetadata = { expectedErrors?: { 'react-compiler'?: number[]; }; }; ``` and can be used like so: ```` ```js {expectedErrors: {'react-compiler': [4]}} // ❌ setState directly in render function Component({value}) { const [count, setCount] = useState(0); setCount(value); // error on L4 return
{count}
; } ``` ```` Because this is defined as a local rule, we don't have the same granular reporting that `eslint-plugin-react-hooks` yet. I can look into that later but for now this first PR just sets us up with something basic. --- .eslintrc | 26 +- .../fixtures/src/content/basic-error.md | 8 + .../src/content/duplicate-metadata.md | 8 + .../src/content/malformed-metadata.md | 8 + .../fixtures/src/content/mixed-language.md | 7 + .../src/content/stale-expected-error.md | 5 + .../fixtures/src/content/suppressed-error.md | 8 + .../lint-markdown-code-blocks.test.js | 124 ++++++ eslint-local-rules/index.js | 47 +++ eslint-local-rules/package.json | 9 + eslint-local-rules/rules/diagnostics.js | 70 ++++ .../rules/lint-markdown-code-blocks.js | 179 +++++++++ eslint-local-rules/rules/markdown.js | 100 +++++ eslint-local-rules/rules/metadata.js | 377 ++++++++++++++++++ eslint-local-rules/rules/react-compiler.js | 115 ++++++ package.json | 8 +- yarn.lock | 4 + 17 files changed, 1097 insertions(+), 6 deletions(-) create mode 100644 eslint-local-rules/__tests__/fixtures/src/content/basic-error.md create mode 100644 eslint-local-rules/__tests__/fixtures/src/content/duplicate-metadata.md create mode 100644 eslint-local-rules/__tests__/fixtures/src/content/malformed-metadata.md create mode 100644 eslint-local-rules/__tests__/fixtures/src/content/mixed-language.md create mode 100644 eslint-local-rules/__tests__/fixtures/src/content/stale-expected-error.md create mode 100644 eslint-local-rules/__tests__/fixtures/src/content/suppressed-error.md create mode 100644 eslint-local-rules/__tests__/lint-markdown-code-blocks.test.js create mode 100644 eslint-local-rules/index.js create mode 100644 eslint-local-rules/package.json create mode 100644 eslint-local-rules/rules/diagnostics.js create mode 100644 eslint-local-rules/rules/lint-markdown-code-blocks.js create mode 100644 eslint-local-rules/rules/markdown.js create mode 100644 eslint-local-rules/rules/metadata.js create mode 100644 eslint-local-rules/rules/react-compiler.js diff --git a/.eslintrc b/.eslintrc index f8b03f98a..5bf9d4067 100644 --- a/.eslintrc +++ b/.eslintrc @@ -2,18 +2,38 @@ "root": true, "extends": "next/core-web-vitals", "parser": "@typescript-eslint/parser", - "plugins": ["@typescript-eslint", "eslint-plugin-react-compiler"], + "plugins": ["@typescript-eslint", "eslint-plugin-react-compiler", "local-rules"], "rules": { "no-unused-vars": "off", "@typescript-eslint/no-unused-vars": ["error", {"varsIgnorePattern": "^_"}], "react-hooks/exhaustive-deps": "error", "react/no-unknown-property": ["error", {"ignore": ["meta"]}], - "react-compiler/react-compiler": "error" + "react-compiler/react-compiler": "error", + "local-rules/lint-markdown-code-blocks": "error" }, "env": { "node": true, "commonjs": true, "browser": true, "es6": true - } + }, + "overrides": [ + { + "files": ["src/content/**/*.md"], + "processor": "local-rules/markdown", + "parser": "espree", + "parserOptions": { + "ecmaVersion": "latest", + "sourceType": "script" + }, + "rules": { + "no-unused-vars": "off", + "@typescript-eslint/no-unused-vars": "off", + "react-hooks/exhaustive-deps": "off", + "react/no-unknown-property": "off", + "react-compiler/react-compiler": "off", + "local-rules/lint-markdown-code-blocks": "error" + } + } + ] } diff --git a/eslint-local-rules/__tests__/fixtures/src/content/basic-error.md b/eslint-local-rules/__tests__/fixtures/src/content/basic-error.md new file mode 100644 index 000000000..8e7670fdc --- /dev/null +++ b/eslint-local-rules/__tests__/fixtures/src/content/basic-error.md @@ -0,0 +1,8 @@ +```jsx +import {useState} from 'react'; +function Counter() { + const [count, setCount] = useState(0); + setCount(count + 1); + return
{count}
; +} +``` diff --git a/eslint-local-rules/__tests__/fixtures/src/content/duplicate-metadata.md b/eslint-local-rules/__tests__/fixtures/src/content/duplicate-metadata.md new file mode 100644 index 000000000..67d6b62bb --- /dev/null +++ b/eslint-local-rules/__tests__/fixtures/src/content/duplicate-metadata.md @@ -0,0 +1,8 @@ +```jsx title="Counter" {expectedErrors: {'react-compiler': [99]}} {expectedErrors: {'react-compiler': [2]}} +import {useState} from 'react'; +function Counter() { + const [count, setCount] = useState(0); + setCount(count + 1); + return
{count}
; +} +``` diff --git a/eslint-local-rules/__tests__/fixtures/src/content/malformed-metadata.md b/eslint-local-rules/__tests__/fixtures/src/content/malformed-metadata.md new file mode 100644 index 000000000..fd542bf03 --- /dev/null +++ b/eslint-local-rules/__tests__/fixtures/src/content/malformed-metadata.md @@ -0,0 +1,8 @@ +```jsx {expectedErrors: {'react-compiler': 'invalid'}} +import {useState} from 'react'; +function Counter() { + const [count, setCount] = useState(0); + setCount(count + 1); + return
{count}
; +} +``` diff --git a/eslint-local-rules/__tests__/fixtures/src/content/mixed-language.md b/eslint-local-rules/__tests__/fixtures/src/content/mixed-language.md new file mode 100644 index 000000000..313b0e30f --- /dev/null +++ b/eslint-local-rules/__tests__/fixtures/src/content/mixed-language.md @@ -0,0 +1,7 @@ +```bash +setCount() +``` + +```txt +import {useState} from 'react'; +``` diff --git a/eslint-local-rules/__tests__/fixtures/src/content/stale-expected-error.md b/eslint-local-rules/__tests__/fixtures/src/content/stale-expected-error.md new file mode 100644 index 000000000..46e330ac0 --- /dev/null +++ b/eslint-local-rules/__tests__/fixtures/src/content/stale-expected-error.md @@ -0,0 +1,5 @@ +```jsx {expectedErrors: {'react-compiler': [3]}} +function Hello() { + return

Hello

; +} +``` diff --git a/eslint-local-rules/__tests__/fixtures/src/content/suppressed-error.md b/eslint-local-rules/__tests__/fixtures/src/content/suppressed-error.md new file mode 100644 index 000000000..ecefa8495 --- /dev/null +++ b/eslint-local-rules/__tests__/fixtures/src/content/suppressed-error.md @@ -0,0 +1,8 @@ +```jsx {expectedErrors: {'react-compiler': [4]}} +import {useState} from 'react'; +function Counter() { + const [count, setCount] = useState(0); + setCount(count + 1); + return
{count}
; +} +``` diff --git a/eslint-local-rules/__tests__/lint-markdown-code-blocks.test.js b/eslint-local-rules/__tests__/lint-markdown-code-blocks.test.js new file mode 100644 index 000000000..90fa1c518 --- /dev/null +++ b/eslint-local-rules/__tests__/lint-markdown-code-blocks.test.js @@ -0,0 +1,124 @@ +const assert = require('assert'); +const fs = require('fs'); +const path = require('path'); +const {ESLint} = require('eslint'); +const plugin = require('..'); + +const FIXTURES_DIR = path.join( + __dirname, + 'fixtures', + 'src', + 'content' +); + +function createESLint({fix = false} = {}) { + return new ESLint({ + useEslintrc: false, + fix, + plugins: { + 'local-rules': plugin, + }, + overrideConfig: { + processor: 'local-rules/markdown', + plugins: ['local-rules'], + rules: { + 'local-rules/lint-markdown-code-blocks': 'error', + }, + parserOptions: { + ecmaVersion: 2020, + sourceType: 'module', + }, + }, + }); +} + +function readFixture(name) { + return fs.readFileSync(path.join(FIXTURES_DIR, name), 'utf8'); +} + +async function lintFixture(name, {fix = false} = {}) { + const eslint = createESLint({fix}); + const filePath = path.join(FIXTURES_DIR, name); + const markdown = readFixture(name); + const [result] = await eslint.lintText(markdown, {filePath}); + return result; +} + +async function run() { + const basicResult = await lintFixture('basic-error.md'); + assert.strictEqual( + basicResult.messages.length, + 1, + 'expected one diagnostic' + ); + assert( + basicResult.messages[0].message.includes('Calling setState during render'), + 'expected message to mention setState during render' + ); + + const suppressedResult = await lintFixture('suppressed-error.md'); + assert.strictEqual( + suppressedResult.messages.length, + 0, + 'expected suppression metadata to silence diagnostic' + ); + + const staleResult = await lintFixture('stale-expected-error.md'); + assert.strictEqual( + staleResult.messages.length, + 1, + 'expected stale metadata error' + ); + assert.strictEqual( + staleResult.messages[0].message, + 'React Compiler expected error on line 3 was not triggered' + ); + + const duplicateResult = await lintFixture('duplicate-metadata.md'); + assert.strictEqual( + duplicateResult.messages.length, + 2, + 'expected duplicate metadata to surface compiler diagnostic and stale metadata notice' + ); + const duplicateFixed = await lintFixture('duplicate-metadata.md', { + fix: true, + }); + assert( + duplicateFixed.output.includes( + "{expectedErrors: {'react-compiler': [4]}}" + ), + 'expected duplicates to be rewritten to a single canonical block' + ); + assert( + !duplicateFixed.output.includes('[99]'), + 'expected stale line numbers to be removed from metadata' + ); + + const mixedLanguageResult = await lintFixture('mixed-language.md'); + assert.strictEqual( + mixedLanguageResult.messages.length, + 0, + 'expected non-js code fences to be ignored' + ); + + const malformedResult = await lintFixture('malformed-metadata.md'); + assert.strictEqual( + malformedResult.messages.length, + 1, + 'expected malformed metadata to fall back to compiler diagnostics' + ); + const malformedFixed = await lintFixture('malformed-metadata.md', { + fix: true, + }); + assert( + malformedFixed.output.includes( + "{expectedErrors: {'react-compiler': [4]}}" + ), + 'expected malformed metadata to be replaced with canonical form' + ); +} + +run().catch(error => { + console.error(error); + process.exitCode = 1; +}); diff --git a/eslint-local-rules/index.js b/eslint-local-rules/index.js new file mode 100644 index 000000000..1566b0ccb --- /dev/null +++ b/eslint-local-rules/index.js @@ -0,0 +1,47 @@ +const lintMarkdownCodeBlocks = require('./rules/lint-markdown-code-blocks'); + +module.exports = { + rules: { + 'lint-markdown-code-blocks': lintMarkdownCodeBlocks, + }, + processors: { + markdown: { + preprocess(text) { + // Hack: wrap the markdown file in a dummy JS comment so ESLint feeds it + // through our custom rule without needing a real markdown parser here. + return [ + `// Markdown content for processing\n/* ${text.replace( + /\*\//g, + '*\\/' + )} */`, + ]; + }, + postprocess(messages) { + const processedMessages = messages.flat().map((message) => { + if (message.suggestions) { + const processedSuggestions = message.suggestions.map( + (suggestion) => { + if (suggestion.fix) { + // Unescape */ in fix text + const fixedText = suggestion.fix.text.replace( + /\*\\\//g, + '*/' + ); + return { + ...suggestion, + fix: {...suggestion.fix, text: fixedText}, + }; + } + return suggestion; + } + ); + return {...message, suggestions: processedSuggestions}; + } + return message; + }); + return processedMessages; + }, + supportsAutofix: true, + }, + }, +}; diff --git a/eslint-local-rules/package.json b/eslint-local-rules/package.json new file mode 100644 index 000000000..5fd9939a9 --- /dev/null +++ b/eslint-local-rules/package.json @@ -0,0 +1,9 @@ +{ + "name": "eslint-plugin-local-rules", + "version": "0.0.0", + "main": "index.js", + "private": "true", + "scripts": { + "test": "node __tests__/lint-markdown-code-blocks.test.js" + } +} diff --git a/eslint-local-rules/rules/diagnostics.js b/eslint-local-rules/rules/diagnostics.js new file mode 100644 index 000000000..886120ae8 --- /dev/null +++ b/eslint-local-rules/rules/diagnostics.js @@ -0,0 +1,70 @@ +function getRelativeLine(loc) { + return loc?.start?.line ?? loc?.line ?? 1; +} + +function getRelativeColumn(loc) { + return loc?.start?.column ?? loc?.column ?? 0; +} + +function getRelativeEndLine(loc, fallbackLine) { + if (loc?.end?.line != null) { + return loc.end.line; + } + if (loc?.line != null) { + return loc.line; + } + return fallbackLine; +} + +function getRelativeEndColumn(loc, fallbackColumn) { + if (loc?.end?.column != null) { + return loc.end.column; + } + if (loc?.column != null) { + return loc.column; + } + return fallbackColumn; +} + +/** + * @param {import('./markdown').MarkdownCodeBlock} block + * @param {Array<{detail: any, loc: any, message: string}>} diagnostics + * @returns {Array<{detail: any, message: string, relativeStartLine: number, markdownLoc: {start: {line: number, column: number}, end: {line: number, column: number}}}>} + */ +function normalizeDiagnostics(block, diagnostics) { + return diagnostics.map(({detail, loc, message}) => { + const relativeStartLine = Math.max(getRelativeLine(loc), 1); + const relativeStartColumn = Math.max(getRelativeColumn(loc), 0); + const relativeEndLine = Math.max( + getRelativeEndLine(loc, relativeStartLine), + relativeStartLine + ); + const relativeEndColumn = Math.max( + getRelativeEndColumn(loc, relativeStartColumn), + relativeStartColumn + ); + + const markdownStartLine = block.codeStartLine + relativeStartLine - 1; + const markdownEndLine = block.codeStartLine + relativeEndLine - 1; + + return { + detail, + message, + relativeStartLine, + markdownLoc: { + start: { + line: markdownStartLine, + column: relativeStartColumn, + }, + end: { + line: markdownEndLine, + column: relativeEndColumn, + }, + }, + }; + }); +} + +module.exports = { + normalizeDiagnostics, +}; diff --git a/eslint-local-rules/rules/lint-markdown-code-blocks.js b/eslint-local-rules/rules/lint-markdown-code-blocks.js new file mode 100644 index 000000000..a3e50c999 --- /dev/null +++ b/eslint-local-rules/rules/lint-markdown-code-blocks.js @@ -0,0 +1,179 @@ +const { + buildFenceLine, + getCompilerExpectedLines, + getSortedUniqueNumbers, + hasCompilerEntry, + metadataEquals, + metadataHasExpectedErrorsToken, + removeCompilerExpectedLines, + setCompilerExpectedLines, +} = require('./metadata'); +const {normalizeDiagnostics} = require('./diagnostics'); +const {parseMarkdownFile} = require('./markdown'); +const {runReactCompiler} = require('./react-compiler'); + +module.exports = { + meta: { + type: 'problem', + docs: { + description: 'Run React Compiler on markdown code blocks', + category: 'Possible Errors', + }, + fixable: 'code', + hasSuggestions: true, + schema: [], + }, + + create(context) { + return { + Program(node) { + const filename = context.getFilename(); + if (!filename.endsWith('.md') || !filename.includes('src/content')) { + return; + } + + const sourceCode = context.getSourceCode(); + let content = sourceCode.text; + + // Extract the markdown from eslint-local-rules/index.js hack + const commentMatch = content.match(/\/\* ([\s\S]*) \*\/$/); + if (commentMatch) { + content = commentMatch[1].replace(/\*\\\//g, '*/'); + } + + const {blocks} = parseMarkdownFile(content, filename); + // For each supported code block, run the compiler and reconcile metadata. + for (const block of blocks) { + const compilerResult = runReactCompiler( + block.code, + `${filename}#codeblock` + ); + + const expectedLines = getCompilerExpectedLines(block.metadata); + const expectedLineSet = new Set(expectedLines); + const diagnostics = normalizeDiagnostics( + block, + compilerResult.diagnostics + ); + + const errorLines = new Set(); + const unexpectedDiagnostics = []; + + for (const diagnostic of diagnostics) { + const line = diagnostic.relativeStartLine; + errorLines.add(line); + if (!expectedLineSet.has(line)) { + unexpectedDiagnostics.push(diagnostic); + } + } + + const normalizedErrorLines = getSortedUniqueNumbers( + Array.from(errorLines) + ); + const missingExpectedLines = expectedLines.filter( + (line) => !errorLines.has(line) + ); + + const desiredMetadata = normalizedErrorLines.length + ? setCompilerExpectedLines(block.metadata, normalizedErrorLines) + : removeCompilerExpectedLines(block.metadata); + + // Compute canonical metadata and attach an autofix when it differs. + const metadataChanged = !metadataEquals( + block.metadata, + desiredMetadata + ); + const replacementLine = buildFenceLine(block.lang, desiredMetadata); + const replacementDiffers = block.fence.rawText !== replacementLine; + const applyReplacementFix = replacementDiffers + ? (fixer) => + fixer.replaceTextRange(block.fence.range, replacementLine) + : null; + + const hasDuplicateMetadata = + block.metadata.hadDuplicateExpectedErrors; + const hasExpectedErrorsMetadata = metadataHasExpectedErrorsToken( + block.metadata + ); + + const shouldFixUnexpected = + Boolean(applyReplacementFix) && + normalizedErrorLines.length > 0 && + (metadataChanged || + hasDuplicateMetadata || + !hasExpectedErrorsMetadata); + + let fixAlreadyAttached = false; + + for (const diagnostic of unexpectedDiagnostics) { + const reportData = { + node, + loc: diagnostic.markdownLoc, + message: diagnostic.message, + }; + + if ( + shouldFixUnexpected && + applyReplacementFix && + !fixAlreadyAttached + ) { + reportData.fix = applyReplacementFix; + reportData.suggest = [ + { + desc: 'Add expectedErrors metadata to suppress these errors', + fix: applyReplacementFix, + }, + ]; + fixAlreadyAttached = true; + } + + context.report(reportData); + } + + // Assert that expectedErrors is actually needed + if ( + Boolean(applyReplacementFix) && + missingExpectedLines.length > 0 && + hasCompilerEntry(block.metadata) + ) { + const plural = missingExpectedLines.length > 1; + const message = plural + ? `React Compiler expected errors on lines ${missingExpectedLines.join( + ', ' + )} were not triggered` + : `React Compiler expected error on line ${missingExpectedLines[0]} was not triggered`; + + const reportData = { + node, + loc: { + start: { + line: block.position.start.line, + column: 0, + }, + end: { + line: block.position.start.line, + column: block.fence.rawText.length, + }, + }, + message, + }; + + if (!fixAlreadyAttached && applyReplacementFix) { + reportData.fix = applyReplacementFix; + fixAlreadyAttached = true; + } else if (applyReplacementFix) { + reportData.suggest = [ + { + desc: 'Remove stale expectedErrors metadata', + fix: applyReplacementFix, + }, + ]; + } + + context.report(reportData); + } + } + }, + }; + }, +}; diff --git a/eslint-local-rules/rules/markdown.js b/eslint-local-rules/rules/markdown.js new file mode 100644 index 000000000..7ca5a936f --- /dev/null +++ b/eslint-local-rules/rules/markdown.js @@ -0,0 +1,100 @@ +const {parseFenceMetadata} = require('./metadata'); + +/** + * @typedef {Object} MarkdownCodeBlock + * @property {string} code + * @property {number} codeStartLine + * @property {{start: {line: number, column: number}, end: {line: number, column: number}}} position + * @property {{lineIndex: number, rawText: string, metaText: string, range: [number, number]}} fence + * @property {string} filePath + * @property {string} lang + * @property {import('./metadata').FenceMetadata} metadata + */ + +const SUPPORTED_LANGUAGES = new Set([ + 'js', + 'jsx', + 'javascript', + 'ts', + 'tsx', + 'typescript', +]); + +function computeLineOffsets(lines) { + const offsets = []; + let currentOffset = 0; + + for (const line of lines) { + offsets.push(currentOffset); + currentOffset += line.length + 1; + } + + return offsets; +} + +function parseMarkdownFile(content, filePath) { + const lines = content.split('\n'); + const lineOffsets = computeLineOffsets(lines); + const blocks = []; + + let currentBlock = null; + + for (let index = 0; index < lines.length; index++) { + const line = lines[index]; + const fenceMatch = line.match(/^```(\w+)(.*)$/); + + if (fenceMatch) { + const lang = fenceMatch[1]; + if (!SUPPORTED_LANGUAGES.has(lang)) { + currentBlock = null; + continue; + } + + const metaPortion = fenceMatch[2] || ''; + const metadata = parseFenceMetadata(metaPortion); + currentBlock = { + lang, + metadata, + filePath, + codeLines: [], + codeStartLine: index + 2, + position: { + start: {line: index + 1, column: 0}, + end: {line: index + 1, column: 0}, + }, + fence: { + lineIndex: index, + rawText: line, + metaText: metaPortion, + range: [lineOffsets[index] || 0, (lineOffsets[index] || 0) + line.length], + }, + }; + continue; + } + + if (line === '```' && currentBlock) { + currentBlock.position.end = {line: index + 1, column: 0}; + currentBlock.code = currentBlock.codeLines.join('\n'); + delete currentBlock.codeLines; + blocks.push(currentBlock); + currentBlock = null; + continue; + } + + if (currentBlock) { + currentBlock.codeLines.push(line); + } + } + + return { + blocks, + lines, + lineOffsets, + }; +} + +module.exports = { + SUPPORTED_LANGUAGES, + computeLineOffsets, + parseMarkdownFile, +}; diff --git a/eslint-local-rules/rules/metadata.js b/eslint-local-rules/rules/metadata.js new file mode 100644 index 000000000..c86741247 --- /dev/null +++ b/eslint-local-rules/rules/metadata.js @@ -0,0 +1,377 @@ +/** + * Utilities for parsing and rewriting markdown code fence metadata. + * + * The rule keeps metadata as structured objects while editing so we only + * stringify at the boundary where we need to emit a replacement fence line. + */ + +/** + * @typedef {{type: 'text', raw: string}} TextToken + * @typedef {{ + * type: 'expectedErrors', + * entries: Record>, + * raw?: string, + * }} ExpectedErrorsToken + * @typedef {TextToken | ExpectedErrorsToken} MetadataToken + * + * @typedef {{ + * leading: string, + * trailing: string, + * tokens: Array, + * parseError: boolean, + * hadDuplicateExpectedErrors: boolean, + * }} FenceMetadata + */ + +const EXPECTED_ERRORS_BLOCK_REGEX = /\{\s*expectedErrors\s*:/; +const REACT_COMPILER_KEY = 'react-compiler'; + +function getSortedUniqueNumbers(values) { + return Array.from(new Set(values)) + .filter((value) => typeof value === 'number' && !Number.isNaN(value)) + .sort((a, b) => a - b); +} + +function tokenizeMeta(body) { + if (!body) { + return []; + } + + const tokens = []; + let current = ''; + let depth = 0; + + for (let i = 0; i < body.length; i++) { + const char = body[i]; + if (char === '{') { + depth++; + } else if (char === '}') { + depth = Math.max(depth - 1, 0); + } + + if (char === ' ' && depth === 0) { + if (current) { + tokens.push(current); + current = ''; + } + continue; + } + + current += char; + } + + if (current) { + tokens.push(current); + } + + return tokens; +} + +function normalizeEntryValues(values) { + if (!Array.isArray(values)) { + return []; + } + return getSortedUniqueNumbers(values); +} + +function parseExpectedErrorsEntries(rawEntries) { + const normalized = rawEntries + .replace(/([{,]\s*)([a-zA-Z_$][\w$]*)\s*:/g, '$1"$2":') + .replace(/'([^']*)'/g, '"$1"'); + + const parsed = JSON.parse(normalized); + const entries = {}; + + if (parsed && typeof parsed === 'object') { + for (const [key, value] of Object.entries(parsed)) { + entries[key] = normalizeEntryValues(Array.isArray(value) ? value.flat() : value); + } + } + + return entries; +} + +function parseExpectedErrorsToken(tokenText) { + const match = tokenText.match(/^\{\s*expectedErrors\s*:\s*(\{[\s\S]*\})\s*\}$/); + if (!match) { + return null; + } + + const entriesSource = match[1]; + let parseError = false; + let entries; + + try { + entries = parseExpectedErrorsEntries(entriesSource); + } catch (error) { + parseError = true; + entries = {}; + } + + return { + token: { + type: 'expectedErrors', + entries, + raw: tokenText, + }, + parseError, + }; +} + +function parseFenceMetadata(metaText) { + if (!metaText) { + return { + leading: '', + trailing: '', + tokens: [], + parseError: false, + hadDuplicateExpectedErrors: false, + }; + } + + const leading = metaText.match(/^\s*/)?.[0] ?? ''; + const trailing = metaText.match(/\s*$/)?.[0] ?? ''; + const bodyStart = leading.length; + const bodyEnd = metaText.length - trailing.length; + const body = metaText.slice(bodyStart, bodyEnd).trim(); + + if (!body) { + return { + leading, + trailing, + tokens: [], + parseError: false, + hadDuplicateExpectedErrors: false, + }; + } + + const tokens = []; + let parseError = false; + let sawExpectedErrors = false; + let hadDuplicateExpectedErrors = false; + + for (const rawToken of tokenizeMeta(body)) { + const normalizedToken = rawToken.trim(); + if (!normalizedToken) { + continue; + } + + if (EXPECTED_ERRORS_BLOCK_REGEX.test(normalizedToken)) { + const parsed = parseExpectedErrorsToken(normalizedToken); + if (parsed) { + if (sawExpectedErrors) { + hadDuplicateExpectedErrors = true; + // Drop duplicates. We'll rebuild the canonical block on write. + continue; + } + tokens.push(parsed.token); + parseError = parseError || parsed.parseError; + sawExpectedErrors = true; + continue; + } + } + + tokens.push({type: 'text', raw: normalizedToken}); + } + + return { + leading, + trailing, + tokens, + parseError, + hadDuplicateExpectedErrors, + }; +} + +function cloneMetadata(metadata) { + return { + leading: metadata.leading, + trailing: metadata.trailing, + parseError: metadata.parseError, + hadDuplicateExpectedErrors: metadata.hadDuplicateExpectedErrors, + tokens: metadata.tokens.map((token) => { + if (token.type === 'expectedErrors') { + const clonedEntries = {}; + for (const [key, value] of Object.entries(token.entries)) { + clonedEntries[key] = [...value]; + } + return {type: 'expectedErrors', entries: clonedEntries}; + } + return {type: 'text', raw: token.raw}; + }), + }; +} + +function findExpectedErrorsToken(metadata) { + return metadata.tokens.find((token) => token.type === 'expectedErrors') || null; +} + +function getCompilerExpectedLines(metadata) { + const token = findExpectedErrorsToken(metadata); + if (!token) { + return []; + } + return getSortedUniqueNumbers(token.entries[REACT_COMPILER_KEY] || []); +} + +function hasCompilerEntry(metadata) { + const token = findExpectedErrorsToken(metadata); + return Boolean(token && token.entries[REACT_COMPILER_KEY]?.length); +} + +function metadataHasExpectedErrorsToken(metadata) { + return Boolean(findExpectedErrorsToken(metadata)); +} + +function stringifyExpectedErrorsToken(token) { + const entries = token.entries || {}; + const keys = Object.keys(entries).filter((key) => entries[key].length > 0); + if (keys.length === 0) { + return ''; + } + + keys.sort(); + + const segments = keys.map((key) => { + const values = entries[key]; + return `'${key}': [${values.join(', ')}]`; + }); + + return `{expectedErrors: {${segments.join(', ')}}}`; +} + +function stringifyFenceMetadata(metadata) { + if (!metadata.tokens.length) { + return ''; + } + + const parts = metadata.tokens + .map((token) => { + if (token.type === 'expectedErrors') { + return stringifyExpectedErrorsToken(token); + } + return token.raw; + }) + .filter(Boolean); + + if (!parts.length) { + return ''; + } + + const leading = metadata.leading || ' '; + const trailing = metadata.trailing ? metadata.trailing.trimEnd() : ''; + const body = parts.join(' '); + return `${leading}${body}${trailing}`; +} + +function buildFenceLine(lang, metadata) { + const meta = stringifyFenceMetadata(metadata); + return meta ? `\`\`\`${lang}${meta}` : `\`\`\`${lang}`; +} + +function metadataEquals(a, b) { + if (a.leading !== b.leading || a.trailing !== b.trailing) { + return false; + } + + if (a.tokens.length !== b.tokens.length) { + return false; + } + + for (let i = 0; i < a.tokens.length; i++) { + const left = a.tokens[i]; + const right = b.tokens[i]; + if (left.type !== right.type) { + return false; + } + if (left.type === 'text') { + if (left.raw !== right.raw) { + return false; + } + } else { + const leftKeys = Object.keys(left.entries).sort(); + const rightKeys = Object.keys(right.entries).sort(); + if (leftKeys.length !== rightKeys.length) { + return false; + } + for (let j = 0; j < leftKeys.length; j++) { + if (leftKeys[j] !== rightKeys[j]) { + return false; + } + const lValues = getSortedUniqueNumbers(left.entries[leftKeys[j]]); + const rValues = getSortedUniqueNumbers(right.entries[rightKeys[j]]); + if (lValues.length !== rValues.length) { + return false; + } + for (let k = 0; k < lValues.length; k++) { + if (lValues[k] !== rValues[k]) { + return false; + } + } + } + } + } + + return true; +} + +function normalizeMetadata(metadata) { + const normalized = cloneMetadata(metadata); + normalized.hadDuplicateExpectedErrors = false; + normalized.parseError = false; + if (!normalized.tokens.length) { + normalized.leading = ''; + normalized.trailing = ''; + } + return normalized; +} + +function setCompilerExpectedLines(metadata, lines) { + const normalizedLines = getSortedUniqueNumbers(lines); + if (normalizedLines.length === 0) { + return removeCompilerExpectedLines(metadata); + } + + const next = cloneMetadata(metadata); + let token = findExpectedErrorsToken(next); + if (!token) { + token = {type: 'expectedErrors', entries: {}}; + next.tokens = [token, ...next.tokens]; + } + + token.entries[REACT_COMPILER_KEY] = normalizedLines; + return normalizeMetadata(next); +} + +function removeCompilerExpectedLines(metadata) { + const next = cloneMetadata(metadata); + const token = findExpectedErrorsToken(next); + if (!token) { + return normalizeMetadata(next); + } + + delete token.entries[REACT_COMPILER_KEY]; + + const hasEntries = Object.values(token.entries).some( + (value) => Array.isArray(value) && value.length > 0 + ); + + if (!hasEntries) { + next.tokens = next.tokens.filter((item) => item !== token); + } + + return normalizeMetadata(next); +} + +module.exports = { + buildFenceLine, + getCompilerExpectedLines, + getSortedUniqueNumbers, + hasCompilerEntry, + metadataEquals, + metadataHasExpectedErrorsToken, + parseFenceMetadata, + removeCompilerExpectedLines, + setCompilerExpectedLines, + stringifyFenceMetadata, +}; diff --git a/eslint-local-rules/rules/react-compiler.js b/eslint-local-rules/rules/react-compiler.js new file mode 100644 index 000000000..1ea002f50 --- /dev/null +++ b/eslint-local-rules/rules/react-compiler.js @@ -0,0 +1,115 @@ +const {transformFromAstSync} = require('@babel/core'); +const {parse: babelParse} = require('@babel/parser'); +const BabelPluginReactCompiler = require('babel-plugin-react-compiler').default; +const { + parsePluginOptions, + validateEnvironmentConfig, +} = require('babel-plugin-react-compiler'); + +const COMPILER_OPTIONS = { + noEmit: true, + panicThreshold: 'none', + environment: validateEnvironmentConfig({ + validateRefAccessDuringRender: true, + validateNoSetStateInRender: true, + validateNoSetStateInEffects: true, + validateNoJSXInTryStatements: true, + validateNoImpureFunctionsInRender: true, + validateStaticComponents: true, + validateNoFreezingKnownMutableFunctions: true, + validateNoVoidUseMemo: true, + validateNoCapitalizedCalls: [], + validateHooksUsage: true, + validateNoDerivedComputationsInEffects: true, + }), +}; + +function hasRelevantCode(code) { + const functionPattern = /^(export\s+)?(default\s+)?function\s+\w+/m; + const arrowPattern = + /^(export\s+)?(const|let|var)\s+\w+\s*=\s*(\([^)]*\)|\w+)\s*=>/m; + const hasImports = /^import\s+/m.test(code); + + return functionPattern.test(code) || arrowPattern.test(code) || hasImports; +} + +function runReactCompiler(code, filename) { + const result = { + sourceCode: code, + events: [], + }; + + if (!hasRelevantCode(code)) { + return {...result, diagnostics: []}; + } + + const options = parsePluginOptions({ + ...COMPILER_OPTIONS, + }); + + options.logger = { + logEvent: (_, event) => { + if (event.kind === 'CompileError') { + const category = event.detail?.category; + if (category === 'Todo' || category === 'Invariant') { + return; + } + result.events.push(event); + } + }, + }; + + try { + const ast = babelParse(code, { + sourceFilename: filename, + sourceType: 'module', + plugins: ['jsx', 'typescript'], + }); + + transformFromAstSync(ast, code, { + filename, + highlightCode: false, + retainLines: true, + plugins: [[BabelPluginReactCompiler, options]], + sourceType: 'module', + configFile: false, + babelrc: false, + }); + } catch (error) { + return {...result, diagnostics: []}; + } + + const diagnostics = []; + + for (const event of result.events) { + if (event.kind !== 'CompileError') { + continue; + } + + const detail = event.detail; + if (!detail) { + continue; + } + + const loc = typeof detail.primaryLocation === 'function' + ? detail.primaryLocation() + : null; + + if (loc == null || typeof loc === 'symbol') { + continue; + } + + const message = typeof detail.printErrorMessage === 'function' + ? detail.printErrorMessage(result.sourceCode, {eslint: true}) + : detail.description || 'Unknown React Compiler error'; + + diagnostics.push({detail, loc, message}); + } + + return {...result, diagnostics}; +} + +module.exports = { + hasRelevantCode, + runReactCompiler, +}; diff --git a/package.json b/package.json index 61d6cd5e4..2367a98f0 100644 --- a/package.json +++ b/package.json @@ -7,8 +7,8 @@ "analyze": "ANALYZE=true next build", "dev": "next-remote-watch ./src/content", "build": "next build && node --experimental-modules ./scripts/downloadFonts.mjs", - "lint": "next lint", - "lint:fix": "next lint --fix", + "lint": "next lint && eslint \"src/content/**/*.md\"", + "lint:fix": "next lint --fix && eslint \"src/content/**/*.md\" --fix", "format:source": "prettier --config .prettierrc --write \"{plugins,src}/**/*.{js,ts,jsx,tsx,css}\"", "nit:source": "prettier --config .prettierrc --list-different \"{plugins,src}/**/*.{js,ts,jsx,tsx,css}\"", "prettier": "yarn format:source", @@ -21,7 +21,8 @@ "postinstall": "is-ci || husky install .husky", "check-all": "npm-run-all prettier lint:fix tsc rss", "rss": "node scripts/generateRss.js", - "deadlinks": "node scripts/deadLinkChecker.js" + "deadlinks": "node scripts/deadLinkChecker.js", + "test:eslint-local-rules": "yarn --cwd eslint-local-rules test" }, "dependencies": { "@codesandbox/sandpack-react": "2.13.5", @@ -69,6 +70,7 @@ "eslint-plugin-flowtype": "4.x", "eslint-plugin-import": "2.x", "eslint-plugin-jsx-a11y": "6.x", + "eslint-plugin-local-rules": "link:eslint-local-rules", "eslint-plugin-react": "7.x", "eslint-plugin-react-compiler": "^19.0.0-beta-e552027-20250112", "eslint-plugin-react-hooks": "^0.0.0-experimental-fabef7a6b-20221215", diff --git a/yarn.lock b/yarn.lock index cc7843bb8..b8480f1c5 100644 --- a/yarn.lock +++ b/yarn.lock @@ -3405,6 +3405,10 @@ eslint-plugin-jsx-a11y@^6.4.1: safe-regex-test "^1.0.3" string.prototype.includes "^2.0.0" +"eslint-plugin-local-rules@link:eslint-local-rules": + version "0.0.0" + uid "" + eslint-plugin-react-compiler@^19.0.0-beta-e552027-20250112: version "19.0.0-beta-e552027-20250112" resolved "https://registry.yarnpkg.com/eslint-plugin-react-compiler/-/eslint-plugin-react-compiler-19.0.0-beta-e552027-20250112.tgz#f4ad9cebe47615ebf6097a8084a30d761ee164f4"