fix: improved support for .cts and .mts extensions

Author: alexander-akait

packages/webpack-cli/src/webpack-cli.ts

@@ -322,37 +322,83 @@ class WebpackCLI implements IWebpackCLI {
     process.exit(2);
   }
 
-  async tryRequireThenImport<T>(module: ModuleName, handleError = true): Promise<T> {
+  async tryRequireThenImport<T>(
+    module: ModuleName,
+    handleError = true,
+    moduleType: "unknown" | "commonjs" | "esm" = "unknown",
+  ): Promise<T> {
     let result;
 
-    try {
-      result = require(module);
-    } catch (error) {
-      const dynamicImportLoader: null | DynamicImport<T> =
-        require("./utils/dynamic-import-loader")();
-      if (
-        ((error as ImportLoaderError).code === "ERR_REQUIRE_ESM" ||
-          process.env.WEBPACK_CLI_FORCE_LOAD_ESM_CONFIG) &&
-        pathToFileURL &&
-        dynamicImportLoader
-      ) {
-        const urlForConfig = pathToFileURL(module);
-
-        result = await dynamicImportLoader(urlForConfig);
-        result = result.default;
+    switch (moduleType) {
+      case "unknown": {
+        try {
+          result = require(module);
+        } catch (error) {
+          const dynamicImportLoader: null | DynamicImport<T> =
+            require("./utils/dynamic-import-loader")();
+          if (
+            ((error as ImportLoaderError).code === "ERR_REQUIRE_ESM" ||
+              process.env.WEBPACK_CLI_FORCE_LOAD_ESM_CONFIG) &&
+            pathToFileURL &&
+            dynamicImportLoader
+          ) {
+            const urlForConfig = pathToFileURL(module);
+
+            result = await dynamicImportLoader(urlForConfig);
+            result = result.default;
+
+            return result;
+          }
 
-        return result;
+          if (handleError) {
+            this.logger.error(error);
+            process.exit(2);
+          } else {
+            throw error;
+          }
+        }
+        break;
       }
+      case "commonjs": {
+        try {
+          result = require(module);
+        } catch (error) {
+          if (handleError) {
+            this.logger.error(error);
+            process.exit(2);
+          } else {
+            throw error;
+          }
+        }
+        break;
+      }
+      case "esm": {
+        try {
+          const dynamicImportLoader: null | DynamicImport<T> =
+            require("./utils/dynamic-import-loader")();
 
-      if (handleError) {
-        this.logger.error(error);
-        process.exit(2);
-      } else {
-        throw error;
+          if (pathToFileURL && dynamicImportLoader) {
+            const urlForConfig = pathToFileURL(module);
+
+            result = await dynamicImportLoader(urlForConfig);
+            result = result.default;
+
+            return result;
+          }
+        } catch (error) {
+          if (handleError) {
+            this.logger.error(error);
+            process.exit(2);
+          } else {
+            throw error;
+          }
+        }
+
+        break;
       }
     }
 
-    // For babel/typescript
+    // For babel and other, only commonjs
     if (result && typeof result === "object" && "default" in result) {
       result = result.default || {};
     }
@@ -1749,8 +1795,15 @@ class WebpackCLI implements IWebpackCLI {
 
     const interpret = require("interpret");
     const loadConfigByPath = async (configPath: string, argv: Argv = {}) => {
-      const ext = path.extname(configPath);
-      const interpreted = Object.keys(interpret.jsVariants).find((variant) => variant === ext);
+      const ext = path.extname(configPath).toLowerCase();
+      let interpreted = interpret.jsVariants[ext];
+
+      // Fallback `.cts` to `.ts`
+      // TODO implement good `.mts` support after https://github.com/gulpjs/rechoir/issues/43
+      // For ESM and `.mts` you need to use: 'NODE_OPTIONS="--loader ts-node/esm" webpack-cli --config ./webpack.config.mts'
+      if (!interpreted && /\.cts$/.test(ext)) {
+        interpreted = interpret.jsVariants[".ts"];
+      }
 
       if (interpreted && !disableInterpret) {
         const rechoir: Rechoir = require("rechoir");
@@ -1777,10 +1830,24 @@ class WebpackCLI implements IWebpackCLI {
 
       type LoadConfigOption = PotentialPromise<WebpackConfiguration>;
 
+      let moduleType: "unknown" | "commonjs" | "esm" = "unknown";
+
+      switch (ext) {
+        case ".cjs":
+        case ".cts":
+          moduleType = "commonjs";
+          break;
+        case ".mjs":
+        case ".mts":
+          moduleType = "esm";
+          break;
+      }
+
       try {
         options = await this.tryRequireThenImport<LoadConfigOption | LoadConfigOption[]>(
           configPath,
           false,
+          moduleType,
         );
         // @ts-expect-error error type assertion
       } catch (error: Error) {
@@ -1897,14 +1964,15 @@ class WebpackCLI implements IWebpackCLI {
         ".cjs",
         ".ts",
         ".cts",
+        ".mts",
         ...Object.keys(interpret.extensions),
       ];
       // Order defines the priority, in decreasing order
-      const defaultConfigFiles = [
-        "webpack.config",
-        ".webpack/webpack.config",
-        ".webpack/webpackfile",
-      ].flatMap((filename) => extensions.map((ext) => path.resolve(filename + ext)));
+      const defaultConfigFiles = new Set(
+        ["webpack.config", ".webpack/webpack.config", ".webpack/webpackfile"].flatMap((filename) =>
+          extensions.map((ext) => path.resolve(filename + ext)),
+        ),
+      );
 
       let foundDefaultConfigFile;
 

test/build/config-format/coffee/webpack.config.coffee

@@ -1,7 +1,7 @@
 path = require 'path'
 
 config =
-    mode: 'production'
+    mode: 'development'
     entry: './main.js'
     output:
         path: path.resolve(__dirname, 'dist')

test/build/config-format/commonjs-default/webpack.config.cjs

@@ -1,7 +1,7 @@
 const path = require("path");
 
 const config = {
-  mode: "production",
+  mode: "development",
   entry: "./main.js",
   output: {
     path: path.resolve(__dirname, "dist"),

test/build/config-format/commonjs/webpack.config.cjs

@@ -1,7 +1,7 @@
 const path = require("path");
 
 const config = {
-  mode: "production",
+  mode: "development",
   entry: "./main.js",
   output: {
     path: path.resolve(__dirname, "dist"),

test/build/config-format/disable-interpret/webpack.config.ts

@@ -2,7 +2,7 @@
 import * as path from "path";
 
 const config = {
-  mode: "production",
+  mode: "development",
   entry: "./main.ts",
   output: {
     path: path.resolve(__dirname, "dist"),

test/build/config-format/mjs/main.js test/build/config-format/esm/main.js

@@ -0,0 +1,11 @@
+const { run } = require("../../../utils/test-utils");
+
+describe("webpack cli", () => {
+  it("should support mjs config format", async () => {
+    const { exitCode, stderr, stdout } = await run(__dirname, ["-c", "webpack.config.mjs"]);
+
+    expect(exitCode).toBe(0);
+    expect(stderr).toBeFalsy();
+    expect(stdout).toBeTruthy();
+  });
+});

test/build/config-format/esm/mjs.test.js

@@ -2,7 +2,7 @@ import { fileURLToPath } from "url";
 import path from "path";
 
 export default {
-  mode: "production",
+  mode: "development",
   entry: "./main.js",
   output: {
     path: path.resolve(path.dirname(fileURLToPath(import.meta.url)), "dist"),

test/build/config-format/mjs/webpack.config.mjs test/build/config-format/esm/webpack.config.mjs

@@ -1,7 +1,7 @@
 path = require 'path'
 
 config =
-    mode: 'production'
+    mode: 'development'
     entry: './main.js'
     output:
         path: path.resolve(__dirname, 'dist')

test/build/config-format/failure/webpack.config.iced

@@ -0,0 +1 @@
+console.log("Main typescript file");

test/build/config-format/mjs/mjs.test.js

@@ -0,0 +1,5 @@
+{
+  "compilerOptions": {
+    "module": "commonjs"
+  }
+}

test/build/config-format/typescript-commonjs/main.ts

@@ -0,0 +1,14 @@
+const { run } = require("../../../utils/test-utils");
+const { existsSync } = require("fs");
+const { resolve } = require("path");
+
+describe("webpack cli", () => {
+  it("should support typescript file", async () => {
+    const { exitCode, stderr, stdout } = await run(__dirname, ["-c", "./webpack.config.cts"]);
+
+    expect(stderr).toBeFalsy();
+    expect(stdout).toBeTruthy();
+    expect(exitCode).toBe(0);
+    expect(existsSync(resolve(__dirname, "dist/foo.bundle.js"))).toBeTruthy();
+  });
+});

test/build/config-format/typescript-commonjs/tsconfig.json

@@ -0,0 +1,16 @@
+/* eslint-disable node/no-unsupported-features/es-syntax */
+/** eslint-disable **/
+import * as path from "path";
+
+// cspell:ignore elopment
+const mode: string = "dev" + "elopment";
+const config = {
+  mode,
+  entry: "./main.ts",
+  output: {
+    path: path.resolve(__dirname, "dist"),
+    filename: "foo.bundle.js",
+  },
+};
+
+export = config;

test/build/config-format/typescript-commonjs/typescript.test.js

@@ -0,0 +1 @@
+console.log("Rimuru Tempest");

test/build/config-format/typescript-commonjs/webpack.config.cts

@@ -0,0 +1,6 @@
+{
+  "type": "module",
+  "engines": {
+    "node": ">=14.15.0"
+  }
+}

test/build/config-format/typescript-esnext-mjs/main.ts

@@ -0,0 +1,6 @@
+{
+  "compilerOptions": {
+    "module": "esnext",
+    "allowSyntheticDefaultImports": true
+  }
+}

test/build/config-format/typescript-esnext-mjs/package.json

@@ -0,0 +1,20 @@
+// eslint-disable-next-line node/no-unpublished-require
+const { run } = require("../../../utils/test-utils");
+const { existsSync } = require("fs");
+const { resolve } = require("path");
+
+describe("webpack cli", () => {
+  it("should support typescript esnext file", async () => {
+    const env = { ...process.env };
+
+    const { exitCode, stderr, stdout } = await run(__dirname, ["-c", "./webpack.config.mts"], {
+      nodeOptions: ["--experimental-loader=ts-node/esm"],
+      env,
+    });
+
+    expect(stderr).not.toBeFalsy(); // Deprecation warning logs on stderr
+    expect(stdout).toBeTruthy();
+    expect(exitCode).toBe(0);
+    expect(existsSync(resolve(__dirname, "dist/foo.bundle.js"))).toBeTruthy();
+  });
+});

test/build/config-format/typescript-esnext-mjs/tsconfig.json

@@ -0,0 +1,15 @@
+/* eslint-disable node/no-unsupported-features/es-syntax */
+import * as path from "path";
+
+// cspell:ignore elopment
+const mode: string = "dev" + "elopment";
+const config = {
+  mode,
+  entry: "./main.ts",
+  output: {
+    path: path.resolve("dist"),
+    filename: "foo.bundle.js",
+  },
+};
+
+export default config;

test/build/config-format/typescript-esnext-mjs/typescript.test.js

@@ -6,13 +6,6 @@ const { resolve } = require("path");
 describe("webpack cli", () => {
   it("should support typescript esnext file", async () => {
     const majorNodeVersion = process.version.slice(1, 3);
-
-    if (majorNodeVersion < 14) {
-      expect(true).toBe(true);
-
-      return;
-    }
-
     const env = { ...process.env };
 
     if (majorNodeVersion >= 20) {

test/build/config-format/typescript-esnext-mjs/webpack.config.mts

@@ -1,8 +1,10 @@
 /* eslint-disable node/no-unsupported-features/es-syntax */
 import * as path from "path";
 
+// cspell:ignore elopment
+const mode: string = "dev" + "elopment";
 const config = {
-  mode: "production",
+  mode,
   entry: "./main.ts",
   output: {
     path: path.resolve("dist"),

test/build/config-format/typescript-esnext/typescript.test.js

@@ -5,6 +5,7 @@ const { resolve } = require("path");
 describe("webpack cli", () => {
   it("should support typescript file", async () => {
     const { exitCode, stderr, stdout } = await run(__dirname, ["-c", "./webpack.config.ts"], {
+      // For `nyc`, remove it when we drop `nyc` usage
       nodeOptions: ["--require=ts-node/register"],
     });
 

test/build/config-format/typescript-esnext/webpack.config.ts

@@ -2,8 +2,10 @@
 /** eslint-disable **/
 import * as path from "path";
 
+// cspell:ignore elopment
+const mode: string = "dev" + "elopment";
 const config = {
-  mode: "production",
+  mode,
   entry: "./main.ts",
   output: {
     path: path.resolve(__dirname, "dist"),