fix: import("eslint") doesn't work (#9)

* fix: import("eslint") doesn't work

fixes #8

* fix: failing tests

* fix: safer import

* Update lib/init/config-file.js

Co-authored-by: Nicholas C. Zakas <nicholas@humanwhocodes.com>

Co-authored-by: Nicholas C. Zakas <nicholas@humanwhocodes.com>

Author: aladdin-add

.gitignore

@@ -6,101 +6,15 @@ yarn-debug.log*
 yarn-error.log*
 lerna-debug.log*
 
-# Diagnostic reports (https://nodejs.org/api/report.html)
-report.[0-9]*.[0-9]*.[0-9]*.[0-9]*.json
-
-# Runtime data
-pids
-*.pid
-*.seed
-*.pid.lock
-
-# Directory for instrumented libs generated by jscoverage/JSCover
-lib-cov
-
 # Coverage directory used by tools like istanbul
 coverage
 *.lcov
 
 # nyc test coverage
 .nyc_output
 
-# Grunt intermediate storage (https://gruntjs.com/creating-plugins#storing-task-files)
-.grunt
-
-# Bower dependency directory (https://bower.io/)
-bower_components
-
-# node-waf configuration
-.lock-wscript
-
-# Compiled binary addons (https://nodejs.org/api/addons.html)
-build/Release
-
 # Dependency directories
 node_modules/
-jspm_packages/
-
-# TypeScript v1 declaration files
-typings/
-
-# TypeScript cache
-*.tsbuildinfo
-
-# Optional npm cache directory
-.npm
-
-# Optional eslint cache
-.eslintcache
-
-# Microbundle cache
-.rpt2_cache/
-.rts2_cache_cjs/
-.rts2_cache_es/
-.rts2_cache_umd/
-
-# Optional REPL history
-.node_repl_history
-
-# Output of 'npm pack'
-*.tgz
-
-# Yarn Integrity file
-.yarn-integrity
-
-# dotenv environment variables file
-.env
-.env.test
-
-# parcel-bundler cache (https://parceljs.org/)
-.cache
-
-# Next.js build output
-.next
-
-# Nuxt.js build / generate output
-.nuxt
-dist
-
-# Gatsby files
-.cache/
-# Comment in the public line in if your project uses Gatsby and *not* Next.js
-# https://nextjs.org/blog/next-9-1#public-directory-support
-# public
-
-# vuepress build output
-.vuepress/dist
-
-# Serverless directories
-.serverless/
-
-# FuseBox cache
-.fusebox/
-
-# DynamoDB Local files
-.dynamodb/
-
-# TernJS port file
-.tern-port
 
-.vscode
+.vscode
+/tmp

lib/init/config-file.js

@@ -12,8 +12,11 @@ import fs from "fs";
 import path from "path";
 import stringify from "json-stable-stringify-without-jsonify";
 import debugEsm from "debug";
+import { pathToFileURL } from "url";
+import { createRequire } from "module";
 
 const debug = debugEsm("eslint:config-file");
+const require = createRequire(path.join(process.cwd(), "./__placeholder__"));
 
 //------------------------------------------------------------------------------
 // Helpers
@@ -31,6 +34,17 @@ function sortByKey(a, b) {
     return a.key > b.key ? 1 : -1;
 }
 
+/**
+ * import local-installed package
+ * @param {string} pkgName the package name to import
+ * @returns {Promise<*>} the exported module
+ */
+async function importLocalPackage(pkgName) {
+    const pkgPath = require.resolve(pkgName);
+
+    return await import(pathToFileURL(pkgPath)); // eslint-disable-line node/no-unsupported-features/es-syntax
+}
+
 //------------------------------------------------------------------------------
 // Private
 //------------------------------------------------------------------------------
@@ -84,8 +98,10 @@ async function writeJSConfigFile(config, filePath) {
     const stringifiedContent = `module.exports = ${stringify(config, { cmp: sortByKey, space: 4 })}\n`;
 
     try {
-        // eslint-disable-next-line node/no-unsupported-features/es-syntax
-        const eslint = (await import("eslint"));
+
+        // import("eslint") won't work when running npx.
+        // as `@eslint/create-config` was installed in npm-cache, while eslint was installed in cwd.
+        const eslint = (await importLocalPackage("eslint")).default;
         const linter = new eslint.ESLint({ baseConfig: config, fix: true, useEslintrc: false });
         const result = await linter.lintText(stringifiedContent);
 

tests/fixtures/eslint/index.js

@@ -0,0 +1,12 @@
+/**
+ * @fileoverview the file is to mock local-installed eslint for testing
+ */
+"use strict";
+const _module = require("module");
+const path = require("path");
+
+const { createRequire } = _module;
+const root = path.resolve(__dirname, "../../../../../../");
+
+const realEslintPath = createRequire(root).resolve("eslint");
+module.exports = require(realEslintPath);

tests/fixtures/eslint/lib/api.js

@@ -1,4 +1,5 @@
 {
     "name": "eslint",
-    "version": "3.18.0"
+    "version": "3.18.0",
+    "main": "./lib/api.js"
 }

tests/fixtures/eslint/package.json

@@ -146,7 +146,7 @@ describe("ConfigFile", () => {
 
             const StubbedConfigFile = await esmock.p("../../lib/init/config-file.js", {
                 fs: fakeFS,
-                eslint: { ESLint: fakeESLint }
+                eslint: { default: { ESLint: fakeESLint } }
             });
 
             nodeAssert.rejects(async () => {

tests/init/config-file.js

@@ -11,16 +11,15 @@
 import chai from "chai";
 import fs from "fs";
 import path from "path";
-import os from "os";
 import sinon from "sinon";
 import sh from "shelljs";
-import * as npmUtils from "../../lib/init/npm-utils.js";
 import esmock from "esmock";
+import { fileURLToPath } from "url";
+import * as npmUtils from "../../lib/init/npm-utils.js";
 
 const originalDir = process.cwd();
 const { assert } = chai;
 
-
 //------------------------------------------------------------------------------
 // Helpers
 //------------------------------------------------------------------------------
@@ -35,7 +34,13 @@ let localInstalledEslintDir;
  */
 function setLocalInstalledEslint(version) {
     const eslintPkgPath = path.join(localInstalledEslintDir, "./package.json");
-    const pkg = version ? { name: "eslint", version } : {};
+    let pkg = JSON.parse(fs.readFileSync(eslintPkgPath, "utf8"));
+
+    if (version) {
+        pkg.version = version;
+    } else {
+        pkg = {};
+    }
 
     fs.writeFileSync(eslintPkgPath, JSON.stringify(pkg, null, 2), "utf8");
 }
@@ -60,7 +65,9 @@ describe("configInitializer", () => {
 
     // copy into clean area so as not to get "infected" by this project's .eslintrc files
     before(() => {
-        fixtureDir = path.join(os.tmpdir(), "eslint/fixtures/config-initializer");
+        const __filename = fileURLToPath(import.meta.url); // eslint-disable-line no-underscore-dangle
+
+        fixtureDir = path.join(__filename, "../../../tmp/eslint/fixtures/config-initializer");
         localInstalledEslintDir = path.join(fixtureDir, "./node_modules/eslint");
         sh.mkdir("-p", localInstalledEslintDir);
         sh.cp("-r", "./tests/fixtures/config-initializer/.", fixtureDir);