8000 fix: new instance of FlatESLint should load latest config file versio… · eslint/eslint@87b2470 · GitHub
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mdjermanovicmdjermanovic
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fix: new instance of FlatESLint should load latest config file version (#16608)
* fix: new instance of FlatESLint should load latest config file version * clear require.cache * add delays
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‎lib/eslint/flat-eslint.js

Lines changed: 37 additions & 1 deletion
Original file line numberDiff line numberDiff line change
@@ -93,6 +93,7 @@ const FLAT_CONFIG_FILENAME = "eslint.config.js";
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const debug = require("debug")("eslint:flat-eslint");
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const removedFormatters = new Set(["table", "codeframe"]);
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const privateMembers = new WeakMap();
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const importedConfigFileModificationTime = new Map();
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/**
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* It will calculate the error and warning count for collection of messages per file
@@ -281,7 +282,42 @@ async function loadFlatConfigFile(filePath) {
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debug(`Config file URL is ${fileURL}`);
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return (await import(fileURL)).default;
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const mtime = (await fs.stat(filePath)).mtime.getTime();
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/*
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* Append a query with the config file's modification time (`mtime`) in order
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* to import the current version of the config file. Without the query, `import()` would
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* cache the config file module by the pathname only, and then always return
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* the same version (the one that was actual when the module was imported for the first time).
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*
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* This ensures that the config file module is loaded and executed again
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* if it has been changed since the last time it was imported.
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* If it hasn't been changed, `import()` will just return the cached version.
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*
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* Note that we should not overuse queries (e.g., by appending the current time
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* to always reload the config file module) as that could cause memory leaks
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* because entries are never removed from the import cache.
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*/
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fileURL.searchParams.append("mtime", mtime);
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/*
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* With queries, we can bypass the import cache. However, when import-ing a CJS module,
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* Node.js uses the require infrastructure under the hood. That includes the require cache,
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* which caches the config file module by its file path (queries have no effect).
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* Therefore, we also need to clear the require cache before importing the config file module.
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* In order to get the same behavior with ESM and CJS config files, in particular - to reload
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* the config file only if it has been changed, we track file modification times and clear
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* the require cache only if the file has been changed.
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*/
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if (importedConfigFileModificationTime.get(filePath) !== mtime) {
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delete require.cache[filePath];
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}
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const config = (await import(fileURL)).default;
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importedConfigFileModificationTime.set(filePath, mtime);
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return config;
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}
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/**

‎tests/lib/eslint/flat-eslint.js

Lines changed: 80 additions & 0 deletions
Original file line numberDiff line numberDiff line change
@@ -11,6 +11,7 @@
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//------------------------------------------------------------------------------
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const assert = require("assert");
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const util = require("util");
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const fs = require("fs");
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const fsp = fs.promises;
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const os = require("os");
@@ -41,6 +42,15 @@ function ensureDirectoryExists(dirPath) {
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}
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}
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/**
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* Does nothing for a given time.
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* @param {number} time Time in ms.
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* @returns {void}
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*/
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async function sleep(time) {
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await util.promisify(setTimeout)(time);
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}
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//------------------------------------------------------------------------------
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// Tests
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//------------------------------------------------------------------------------
@@ -5305,4 +5315,74 @@ describe("FlatESLint", () => {
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});
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});
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describe("config file", () => {
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it("new instance of FlatESLint should use the latest version of the config file (ESM)", async () => {
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const cwd = path.join(getFixturePath(), `config_file_${Date.now()}`);
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const configFileContent = "export default [{ rules: { semi: ['error', 'always'] } }];";
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const teardown = createCustomTeardown({
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cwd,
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files: {
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"package.json": '{ "type": "module" }',
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"eslint.config.js": configFileContent,
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"a.js": "foo\nbar;"
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}
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});
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await teardown.prepare();
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let eslint = new FlatESLint({ cwd });
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let [{ messages }] = await eslint.lintFiles(["a.js"]);
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assert.strictEqual(messages.length, 1);
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assert.strictEqual(messages[0].ruleId, "semi");
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assert.strictEqual(messages[0].messageId, "missingSemi");
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assert.strictEqual(messages[0].line, 1);
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await sleep(100);
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await fsp.writeFile(path.join(cwd, "eslint.config.js"), configFileContent.replace("always", "never"));
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eslint = new FlatESLint({ cwd });
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[{ messages }] = await eslint.lintFiles(["a.js"]);
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assert.strictEqual(messages.length, 1);
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assert.strictEqual(messages[0].ruleId, "semi");
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assert.strictEqual(messages[0].messageId, "extraSemi");
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assert.strictEqual(messages[0].line, 2);
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});
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it("new instance of FlatESLint should use the latest version of the config file (CJS)", async () => {
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const cwd = path.join(getFixturePath(), `config_file_${Date.now()}`);
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const configFileContent = "module.exports = [{ rules: { semi: ['error', 'always'] } }];";
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const teardown = createCustomTeardown({
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cwd,
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files: {
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"eslint.config.js": configFileContent,
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"a.js": "foo\nbar;"
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}
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});
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await teardown.prepare();
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let eslint = new FlatESLint({ cwd });
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let [{ messages }] = await eslint.lintFiles(["a.js"]);
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assert.strictEqual(messages.length, 1);
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assert.strictEqual(messages[0].ruleId, "semi");
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assert.strictEqual(messages[0].messageId, "missingSemi");
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assert.strictEqual(messages[0].line, 1);
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await sleep(100);
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await fsp.writeFile(path.join(cwd, "eslint.config.js"), configFileContent.replace("always", "never"));
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eslint = new FlatESLint({ cwd });
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[{ messages }] = await eslint.lintFiles(["a.js"]);
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assert.strictEqual(messages.length, 1);
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assert.strictEqual(messages[0].ruleId, "semi");
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assert.strictEqual(messages[0].messageId, "extraSemi");
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assert.strictEqual(messages[0].line, 2);
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});
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});
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});

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