[eslint-patch] Allow for extended shareable ESLint configurations to use any name

common/changes/@rushstack/eslint-patch/user-danade-EslintResolverTweaks_2022-01-07-22-37.json

@@ -0,0 +1,10 @@
+{
+  "changes": [
+    {
+      "packageName": "@rushstack/eslint-patch",
+      "comment": "Allow consumption of non-\"eslint-config-\" prefixed shareable configs",
+      "type": "minor"
+    }
+  ],
+  "packageName": "@rushstack/eslint-patch"
+}

eslint/eslint-patch/src/_patch-base.ts

@@ -0,0 +1,202 @@
+// Copyright (c) Microsoft Corporation. All rights reserved. Licensed under the MIT license.
+// See LICENSE in the project root for license information.
+
+const path = require('path');
+const fs = require('fs');
+
+const isModuleResolutionError: (ex: unknown) => boolean = (ex) =>
+  typeof ex === 'object' && !!ex && 'code' in ex && (ex as { code: unknown }).code === 'MODULE_NOT_FOUND';
+
+// Module path for eslintrc.cjs
+// Example: ".../@eslint/eslintrc/dist/eslintrc.cjs"
+let eslintrcBundlePath: string | undefined = undefined;
+
+// Module path for config-array-factory.js
+// Example: ".../@eslint/eslintrc/lib/config-array-factory"
+let configArrayFactoryPath: string | undefined = undefined;
+
+// Module path for naming.js
+// Example: ".../@eslint/eslintrc/lib/shared/naming"
+let namingPath: string | undefined = undefined;
+
+// Module path for relative-module-resolver.js
+// Example: ".../@eslint/eslintrc/lib/shared/relative-module-resolver"
+let moduleResolverPath: string | undefined = undefined;
+
+// Folder path where ESLint's package.json can be found
+// Example: ".../node_modules/eslint"
+let eslintFolder: string | undefined = undefined;
+
+// Probe for the ESLint >=8.0.0 layout:
+for (let currentModule = module; ; ) {
+  if (!eslintrcBundlePath) {
+    // For ESLint >=8.0.0, all @eslint/eslintrc code is bundled at this path:
+    //   .../@eslint/eslintrc/dist/eslintrc.cjs
+    try {
+      const eslintrcFolder = path.dirname(
+        require.resolve('@eslint/eslintrc/package.json', { paths: [currentModule.path] })
+      );
+
+      // Make sure we actually resolved the module in our call path
+      // and not some other spurious dependency.
+      if (path.join(eslintrcFolder, 'dist/eslintrc.cjs') === currentModule.filename) {
+        eslintrcBundlePath = path.join(eslintrcFolder, 'dist/eslintrc.cjs');
+      }
+    } catch (ex: unknown) {
+      // Module resolution failures are expected, as we're walking
+      // up our require stack to look for eslint. All other errors
+      // are rethrown.
+      if (!isModuleResolutionError(ex)) {
+        throw ex;
+      }
+    }
+  } else {
+    // Next look for a file in ESLint's folder
+    //   .../eslint/lib/cli-engine/cli-engine.js
+    try {
+      const eslintCandidateFolder = path.dirname(
+        require.resolve('eslint/package.json', {
+          paths: [currentModule.path]
+        })
+      );
+
+      // Make sure we actually resolved the module in our call path
+      // and not some other spurious dependency.
+      if (path.join(eslintCandidateFolder, 'lib/cli-engine/cli-engine.js') === currentModule.filename) {
+        eslintFolder = eslintCandidateFolder;
+        break;
+      }
+    } catch (ex: unknown) {
+      // Module resolution failures are expected, as we're walking
+      // up our require stack to look for eslint. All other errors
+      // are rethrown.
+      if (!isModuleResolutionError(ex)) {
+        throw ex;
+      }
+    }
+  }
+
+  if (!currentModule.parent) {
+    break;
+  }
+  currentModule = currentModule.parent;
+}
+
+if (!eslintFolder) {
+  // Probe for the ESLint >=7.8.0 layout:
+  for (let currentModule = module; ; ) {
+    if (!configArrayFactoryPath) {
+      // For ESLint >=7.8.0, config-array-factory.js is at this path:
+      //   .../@eslint/eslintrc/lib/config-array-factory.js
+      try {
+        const eslintrcFolder = path.dirname(
+          require.resolve('@eslint/eslintrc/package.json', {
+            paths: [currentModule.path]
+          })
+        );
+
+        if (path.join(eslintrcFolder, '/lib/config-array-factory.js') == currentModule.filename) {
+          configArrayFactoryPath = path.join(eslintrcFolder, 'lib/config-array-factory.js');
+          moduleResolverPath = path.join(eslintrcFolder, 'lib/shared/relative-module-resolver');
+          namingPath = path.join(eslintrcFolder, 'lib/shared/naming');
+        }
+      } catch (ex: unknown) {
+        // Module resolution failures are expected, as we're walking
+        // up our require stack to look for eslint. All other errors
+        // are rethrown.
+        if (!isModuleResolutionError(ex)) {
+          throw ex;
+        }
+      }
+    } else {
+      // Next look for a file in ESLint's folder
+      //   .../eslint/lib/cli-engine/cli-engine.js
+      try {
+        const eslintCandidateFolder = path.dirname(
+          require.resolve('eslint/package.json', {
+            paths: [currentModule.path]
+          })
+        );
+
+        if (path.join(eslintCandidateFolder, 'lib/cli-engine/cli-engine.js') == currentModule.filename) {
+          eslintFolder = eslintCandidateFolder;
+          break;
+        }
+      } catch (ex: unknown) {
+        // Module resolution failures are expected, as we're walking
+        // up our require stack to look for eslint. All other errors
+        // are rethrown.
+        if (!isModuleResolutionError(ex)) {
+          throw ex;
+        }
+      }
+    }
+
+    if (!currentModule.parent) {
+      break;
+    }
+    currentModule = currentModule.parent;
+  }
+}
+
+if (!eslintFolder) {
+  // Probe for the <7.8.0 layout:
+  for (let currentModule = module; ; ) {
+    // For ESLint <7.8.0, config-array-factory.js was at this path:
+    //   .../eslint/lib/cli-engine/config-array-factory.js
+    if (/[\\/]eslint[\\/]lib[\\/]cli-engine[\\/]config-array-factory\.js$/i.test(currentModule.filename)) {
+      eslintFolder = path.join(path.dirname(currentModule.filename), '../..');
+      configArrayFactoryPath = path.join(eslintFolder, 'lib/cli-engine/config-array-factory');
+      moduleResolverPath = path.join(eslintFolder, 'lib/shared/relative-module-resolver');
+      namingPath = path.join(eslintFolder, 'lib/shared/naming');
+      break;
+    }
+
+    if (!currentModule.parent) {
+      // This was tested with ESLint 6.1.0 .. 7.12.1.
+      throw new Error(
+        'Failed to patch ESLint because the calling module was not recognized.\n' +
+          'If you are using a newer ESLint version that may be unsupported, please create a GitHub issue:\n' +
+          'https://github.com/microsoft/rushstack/issues'
+      );
+    }
+    currentModule = currentModule.parent;
+  }
+}
+
+// Detect the ESLint package version
+const eslintPackageJson = fs.readFileSync(path.join(eslintFolder, 'package.json')).toString();
+const eslintPackageObject = JSON.parse(eslintPackageJson);
+const eslintPackageVersion = eslintPackageObject.version;
+const versionMatch = /^([0-9]+)\./.exec(eslintPackageVersion); // parse the SemVer MAJOR part
+if (!versionMatch) {
+  throw new Error('Unable to parse ESLint version: ' + eslintPackageVersion);
+}
+const eslintMajorVersion = Number(versionMatch[1]);
+if (!(eslintMajorVersion >= 6 && eslintMajorVersion <= 8)) {
+  throw new Error(
+    'The patch-eslint.js script has only been tested with ESLint version 6.x, 7.x, and 8.x.' +
+      ` (Your version: ${eslintPackageVersion})\n` +
+      'Consider reporting a GitHub issue:\n' +
+      'https://github.com/microsoft/rushstack/issues'
+  );
+}
+
+let ConfigArrayFactory: any;
+if (eslintMajorVersion === 8) {
+  ConfigArrayFactory = require(eslintrcBundlePath!).Legacy.ConfigArrayFactory;
+} else {
+  ConfigArrayFactory = require(configArrayFactoryPath!).ConfigArrayFactory;
+}
+
+let ModuleResolver: { resolve: any };
+let Naming: { normalizePackageName: any };
+if (eslintMajorVersion === 8) {
+  ModuleResolver = require(eslintrcBundlePath!).Legacy.ModuleResolver;
+  Naming = require(eslintrcBundlePath!).Legacy.naming;
+} else {
+  ModuleResolver = require(moduleResolverPath!);
+  Naming = require(namingPath!);
+}
+
+export { ConfigArrayFactory, ModuleResolver, Naming, eslintMajorVersion as EslintMajorVersion };

eslint/eslint-patch/src/custom-config-package-names.ts

@@ -0,0 +1,43 @@
+// Copyright (c) Microsoft Corporation. All rights reserved. Licensed under the MIT license.
+// See LICENSE in the project root for license information.
+
+// This is a workaround for ESLint's requirement to consume shareable configurations from package names prefixed
+// with "eslint-config".
+//
+// To remove this requirement, add this line to the top of your project's .eslintrc.js file:
+//
+//    require("@rushstack/eslint-patch/custom-config-package-names");
+//
+import { ConfigArrayFactory, ModuleResolver, Naming } from './_patch-base';
+
+if (!ConfigArrayFactory.__loadExtendedShareableConfigPatched) {
+  ConfigArrayFactory.__loadExtendedShareableConfigPatched = true;
+  const originalLoadExtendedShareableConfig = ConfigArrayFactory.prototype._loadExtendedShareableConfig;
+
+  ConfigArrayFactory.prototype._loadExtendedShareableConfig = function (extendName: string) {
+    const originalResolve = ModuleResolver.resolve;
+    try {
+      ModuleResolver.resolve = function (moduleName: string, relativeToPath: string) {
+        try {
+          return originalResolve.call(this, moduleName, relativeToPath);
+        } catch (e) {
+          // Only change the name we resolve if we cannot find the normalized module, since it is
+          // valid to rely on the normalized package name. Use the originally provided module path
+          // instead of the normalized module path.
+          if (
+            (e as NodeJS.ErrnoException)?.code === 'MODULE_NOT_FOUND' &&
+            moduleName !== extendName &&
+            moduleName === Naming.normalizePackageName(extendName, 'eslint-config')
+          ) {
+            return originalResolve.call(this, extendName, relativeToPath);
+          } else {
+            throw e;
+          }
+        }
+      };
+      return originalLoadExtendedShareableConfig.apply(this, arguments);
+    } finally {
+      ModuleResolver.resolve = originalResolve;
+    }
+  };
+}