Add lintFiles() tests

lib/eslint/eslint.js

@@ -136,10 +136,10 @@ function processOptions({
     ignore = true,
     ignorePath = null,
     ignorePattern = [],
-    parser = "espree",
+    parser = null, // Question: if this is set to a default value it ends up overriding the value set in the config. That seems like unexpected behavior to me.
     parserOptions = {}, // TODO: Is this correct?
     plugins = [],
-    reportUnusedDisableDirectives = false,
+    reportUnusedDisableDirectives = null,
     resolvePluginsRelativeTo = cwd,
     rulePaths = [],
     rules = {}, // TODO: Is this correct?
@@ -214,8 +214,8 @@ function processOptions({
         throw new Error("ignorePattern must be a string or an array of strings.");
     }
 
-    if (typeof parser !== "string") {
-        throw new Error("parser must be a string.");
+    if (typeof parser !== "string" && parser !== null) {
+        throw new Error("parser must be a string or null.");
     }
 
     if (typeof parserOptions !== "object" && parserOptions !== null) {
@@ -226,8 +226,8 @@ function processOptions({
         throw new Error("plugins must be an array.");
     }
 
-    if (typeof reportUnusedDisableDirectives !== "boolean") {
-        throw new Error("reportUnusedDisableDirectives must be a boolean.");
+    if (typeof reportUnusedDisableDirectives !== "boolean" && reportUnusedDisableDirectives !== null) {
+        throw new Error("reportUnusedDisableDirectives must be a boolean or null.");
     }
 
     if (typeof resolvePluginsRelativeTo !== "string") {

tests/lib/cli-engine/_utils.js → tests/_utils/in-memory-fs.js

@@ -2,12 +2,13 @@
  * @fileoverview Define classes what use the in-memory file system.
  *
  * This provides utilities to test `ConfigArrayFactory`,
- * `CascadingConfigArrayFactory`, `FileEnumerator`, and `CLIEngine`.
+ * `CascadingConfigArrayFactory`, `FileEnumerator`, `CLIEngine`, and `ESLint`.
  *
  * - `defineConfigArrayFactoryWithInMemoryFileSystem({ cwd, files })`
  * - `defineCascadingConfigArrayFactoryWithInMemoryFileSystem({ cwd, files })`
  * - `defineFileEnumeratorWithInMemoryFileSystem({ cwd, files })`
  * - `defineCLIEngineWithInMemoryFileSystem({ cwd, files })`
+ * - `defineESLintWithInMemoryFileSystem({ cwd, files })`
  *
  * Those functions define correspond classes with the in-memory file system.
  * Those search config files, parsers, and plugins in the `files` option via the
@@ -55,30 +56,33 @@
 
 const path = require("path");
 const vm = require("vm");
+const { Volume, createFsFromVolume } = require("memfs");
 const Proxyquire = require("proxyquire/lib/proxyquire");
-const { defineInMemoryFs } = require("../_utils");
 
 const CascadingConfigArrayFactoryPath =
-    require.resolve("../../../lib/cli-engine/cascading-config-array-factory");
+    require.resolve("../../lib/cli-engine/cascading-config-array-factory");
 const CLIEnginePath =
-    require.resolve("../../../lib/cli-engine/cli-engine");
+    require.resolve("../../lib/cli-engine/cli-engine");
 const ConfigArrayFactoryPath =
-    require.resolve("../../../lib/cli-engine/config-array-factory");
+    require.resolve("../../lib/cli-engine/config-array-factory");
 const FileEnumeratorPath =
-    require.resolve("../../../lib/cli-engine/file-enumerator");
+    require.resolve("../../lib/cli-engine/file-enumerator");
 const LoadRulesPath =
-    require.resolve("../../../lib/cli-engine/load-rules");
+    require.resolve("../../lib/cli-engine/load-rules");
+const ESLintPath =
+    require.resolve("../../lib/eslint/eslint");
 const ESLintAllPath =
-    require.resolve("../../../conf/eslint-all");
+    require.resolve("../../conf/eslint-all");
 const ESLintRecommendedPath =
-    require.resolve("../../../conf/eslint-recommended");
+    require.resolve("../../conf/eslint-recommended");
 
 // Ensure the needed files has been loaded and cached.
 require(CascadingConfigArrayFactoryPath);
 require(CLIEnginePath);
 require(ConfigArrayFactoryPath);
 require(FileEnumeratorPath);
 require(LoadRulesPath);
+require(ESLintPath);
 require("js-yaml");
 require("espree");
 
@@ -236,12 +240,57 @@ function fsImportFresh(fs, stubs, absolutePath) {
     );
 }
 
+/**
+ * Define in-memory file system.
+ * @param {Object} options The options.
+ * @param {() => string} [options.cwd] The current working directory.
+ * @param {Object} [options.files] The initial files definition in the in-memory file system.
+ * @returns {import("fs")} The stubbed `ConfigArrayFactory` class.
+ */
+function defineInMemoryFs({
+    cwd = process.cwd,
+    files = {}
+} = {}) {
+
+    /**
+     * The in-memory file system for this mock.
+     * @type {import("fs")}
+     */
+    const fs = createFsFromVolume(new Volume());
+
+    fs.mkdirSync(cwd(), { recursive: true });
+
+    /*
+     * Write all files to the in-memory file system and compile all JavaScript
+     * files then set to `stubs`.
+     */
+    (function initFiles(directoryPath, definition) {
+        for (const [filename, content] of Object.entries(definition)) {
+            const filePath = path.resolve(directoryPath, filename);
+            const parentPath = path.dirname(filePath);
+
+            if (typeof content === "object") {
+                initFiles(filePath, content);
+            } else if (typeof content === "string") {
+                if (!fs.existsSync(parentPath)) {
+                    fs.mkdirSync(parentPath, { recursive: true });
+                }
+                fs.writeFileSync(filePath, content);
+            } else {
+                throw new Error(`Invalid content: ${typeof content}`);
+            }
+        }
+    }(cwd(), files));
+
+    return fs;
+}
+
 /**
  * Define stubbed `ConfigArrayFactory` class what uses the in-memory file system.
  * @param {Object} options The options.
  * @param {() => string} [options.cwd] The current working directory.
  * @param {Object} [options.files] The initial files definition in the in-memory file system.
- * @returns {{ fs: import("fs"), RelativeModuleResolver: import("../../../lib/shared/relative-module-resolver"), ConfigArrayFactory: import("../../../lib/cli-engine/config-array-factory")["ConfigArrayFactory"] }} The stubbed `ConfigArrayFactory` class.
+ * @returns {{ fs: import("fs"), RelativeModuleResolver: import("../../lib/shared/relative-module-resolver"), ConfigArrayFactory: import("../../lib/cli-engine/config-array-factory")["ConfigArrayFactory"] }} The stubbed `ConfigArrayFactory` class.
  */
 function defineConfigArrayFactoryWithInMemoryFileSystem({
     cwd = process.cwd,
@@ -438,9 +487,52 @@ function defineCLIEngineWithInMemoryFileSystem({
     };
 }
 
+/**
+ * Define stubbed `ESLint` class that uses the in-memory file system.
+ * @param {Object} options The options.
+ * @param {() => string} [options.cwd] The current working directory.
+ * @param {Object} [options.files] The initial files definition in the in-memory file system.
+ * @returns {{ fs: import("fs"), RelativeModuleResolver: import("../../lib/shared/relative-module-resolver"), ConfigArrayFactory: import("../../lib/cli-engine/config-array-factory")["ConfigArrayFactory"], CascadingConfigArrayFactory: import("../../lib/cli-engine/cascading-config-array-factory")["CascadingConfigArrayFactory"], FileEnumerator: import("../../lib/cli-engine/file-enumerator")["FileEnumerator"], ESLint: import("../../lib/eslint/eslint")["ESLint"], getCLIEngineInternalSlots: import("../../lib//eslint/eslint")["getESLintInternalSlots"] }} The stubbed `ESLint` class.
+ */
+function defineESLintWithInMemoryFileSystem({
+    cwd = process.cwd,
+    files = {}
+} = {}) {
+    const {
+        fs,
+        RelativeModuleResolver,
+        ConfigArrayFactory,
+        CascadingConfigArrayFactory,
+        FileEnumerator,
+        CLIEngine
+    } = defineCLIEngineWithInMemoryFileSystem({ cwd, files });
+    const { ESLint, getESLintInternalSlots } = proxyquire(ESLintPath, {
+        "../cli-engine": { CLIEngine }
+    });
+
+    // Override the default cwd.
+    return {
+        fs,
+        RelativeModuleResolver,
+        ConfigArrayFactory,
+        CascadingConfigArrayFactory,
+        FileEnumerator,
+        ESLint: cwd === process.cwd
+            ? ESLint
+            : class extends ESLint {
+                constructor(options) {
+                    super({ cwd: cwd(), ...options });
+                }
+            },
+        getESLintInternalSlots
+    };
+}
+
 module.exports = {
+    defineInMemoryFs,
     defineConfigArrayFactoryWithInMemoryFileSystem,
     defineCascadingConfigArrayFactoryWithInMemoryFileSystem,
     defineFileEnumeratorWithInMemoryFileSystem,
-    defineCLIEngineWithInMemoryFileSystem
+    defineCLIEngineWithInMemoryFileSystem,
+    defineESLintWithInMemoryFileSystem
 };

tests/_utils/index.js

@@ -0,0 +1,39 @@
+"use strict";
+
+const {
+    defineInMemoryFs,
+    defineConfigArrayFactoryWithInMemoryFileSystem,
+    defineCascadingConfigArrayFactoryWithInMemoryFileSystem,
+    defineFileEnumeratorWithInMemoryFileSystem,
+    defineCLIEngineWithInMemoryFileSystem,
+    defineESLintWithInMemoryFileSystem
+} = require("./in-memory-fs");
+
+
+/**
+ * Prevents leading spaces in a multiline template literal from appearing in the resulting string
+ * @param {string[]} strings The strings in the template literal
+ * @param {any[]} values The interpolation values in the template literal.
+ * @returns {string} The template literal, with spaces removed from all lines
+ */
+function unIndent(strings, ...values) {
+    const text = strings
+        .map((s, i) => (i === 0 ? s : values[i - 1] + s))
+        .join("");
+    const lines = text.replace(/^\n/u, "").replace(/\n\s*$/u, "").split("\n");
+    const lineIndents = lines.filter(line => line.trim()).map(line => line.match(/ */u)[0].length);
+    const minLineIndent = Math.min(...lineIndents);
+
+    return lines.map(line => line.slice(minLineIndent)).join("\n");
+}
+
+
+module.exports = {
+    unIndent,
+    defineInMemoryFs,
+    defineConfigArrayFactoryWithInMemoryFileSystem,
+    defineCascadingConfigArrayFactoryWithInMemoryFileSystem,
+    defineFileEnumeratorWithInMemoryFileSystem,
+    defineCLIEngineWithInMemoryFileSystem,
+    defineESLintWithInMemoryFileSystem
+};

tests/lib/cli-engine/cascading-config-array-factory.js

@@ -12,7 +12,7 @@ const sh = require("shelljs");
 const sinon = require("sinon");
 const { ConfigArrayFactory } = require("../../../lib/cli-engine/config-array-factory");
 const { ExtractedConfig } = require("../../../lib/cli-engine/config-array/extracted-config");
-const { defineCascadingConfigArrayFactoryWithInMemoryFileSystem } = require("./_utils");
+const { defineCascadingConfigArrayFactoryWithInMemoryFileSystem } = require("../../_utils");
 
 /** @typedef {InstanceType<ReturnType<defineCascadingConfigArrayFactoryWithInMemoryFileSystem>["CascadingConfigArrayFactory"]>} CascadingConfigArrayFactory */
 /** @typedef {ReturnType<CascadingConfigArrayFactory["getConfigArrayForFile"]>} ConfigArray */

tests/lib/cli-engine/cli-engine.js

@@ -18,8 +18,7 @@ const assert = require("chai").assert,
     os = require("os"),
     hash = require("../../../lib/cli-engine/hash"),
     { CascadingConfigArrayFactory } = require("../../../lib/cli-engine/cascading-config-array-factory"),
-    { unIndent } = require("../_utils"),
-    { defineCLIEngineWithInMemoryFileSystem } = require("./_utils");
+    { unIndent, defineCLIEngineWithInMemoryFileSystem } = require("../../_utils");
 
 const proxyquire = require("proxyquire").noCallThru().noPreserveCache();
 const fCache = require("file-entry-cache");

tests/lib/cli-engine/config-array-factory.js

@@ -10,7 +10,7 @@ const { assert } = require("chai");
 const { spy } = require("sinon");
 const { ConfigArray } = require("../../../lib/cli-engine/config-array");
 const { OverrideTester } = require("../../../lib/cli-engine/config-array");
-const { defineConfigArrayFactoryWithInMemoryFileSystem } = require("./_utils");
+const { defineConfigArrayFactoryWithInMemoryFileSystem } = require("../../_utils");
 
 const tempDir = path.join(os.tmpdir(), "eslint/config-array-factory");
 

tests/lib/cli-engine/file-enumerator.js

@@ -11,7 +11,7 @@ const { assert } = require("chai");
 const sh = require("shelljs");
 const { CascadingConfigArrayFactory } =
     require("../../../lib/cli-engine/cascading-config-array-factory");
-const { defineFileEnumeratorWithInMemoryFileSystem } = require("./_utils");
+const { defineFileEnumeratorWithInMemoryFileSystem } = require("../../_utils");
 
 describe("FileEnumerator", () => {
     describe("'iterateFiles(patterns)' method should iterate files and configs.", () => {