feat: support ECMA modules for the executableFile option (#66)

.gitignore

@@ -7,7 +7,6 @@ Thumbs.db
 *.sublime-project
 *.sublime-workspace
 
-/jest*
 /dist
 /local
 /reports

.husky/.gitignore

@@ -1 +1 @@
-_
+_

jest.config.js

@@ -0,0 +1,7 @@
+module.exports = {
+  transformIgnorePatterns: [
+    "/node_modules/",
+    "\\.pnp\\.[^\\/]+$",
+    "/test/fixtures/",
+  ],
+};

package.json

@@ -25,14 +25,13 @@
     "lint:prettier": "prettier --list-different .",
     "lint:js": "eslint --cache .",
     "lint": "npm-run-all -l -p \"lint:**\"",
-    "test:only": "cross-env NODE_ENV=test jest",
+    "test:only": "cross-env NODE_ENV=test NODE_OPTIONS=--experimental-vm-modules jest",
     "test:watch": "npm run test:only -- --watch",
     "test:coverage": "npm run test:only -- --collectCoverageFrom=\"src/**/*.js\" --coverage",
     "pretest": "npm run lint",
     "test": "npm run test:coverage",
     "prepare": "npm run build",
     "release": "standard-version",
-    "defaults": "webpack-defaults",
     "postinstall": "husky install",
     "prepublishOnly": "pinst --disable",
     "postpublish": "pinst --enable"
@@ -44,31 +43,29 @@
     "webpack": "^5.0.0"
   },
   "devDependencies": {
-    "@babel/cli": "^7.12.16",
-    "@babel/core": "^7.12.16",
-    "@babel/preset-env": "^7.12.16",
-    "@commitlint/cli": "^11.0.0",
-    "@commitlint/config-conventional": "^11.0.0",
-    "@webpack-contrib/defaults": "^6.3.0",
+    "@babel/cli": "^7.13.0",
+    "@babel/core": "^7.13.8",
+    "@babel/preset-env": "^7.13.8",
+    "@commitlint/cli": "^12.0.1",
+    "@commitlint/config-conventional": "^12.0.1",
     "@webpack-contrib/eslint-config-webpack": "^3.0.0",
-    "babel-jest": "^26.6.3",
     "cross-env": "^7.0.3",
     "del": "^6.0.0",
     "del-cli": "^3.0.1",
-    "eslint": "^7.20.0",
-    "eslint-config-prettier": "^7.2.0",
+    "eslint": "^7.21.0",
+    "eslint-config-prettier": "^8.1.0",
     "eslint-plugin-import": "^2.22.1",
     "figlet": "^1.5.0",
-    "husky": "^5.0.9",
+    "husky": "^5.1.2",
     "jest": "^26.6.3",
     "lint-staged": "^10.5.4",
     "memfs": "^3.2.0",
     "modernizr": "^3.11.4",
     "npm-run-all": "^4.1.5",
-    "pinst": "^2.1.4",
+    "pinst": "^2.1.6",
     "prettier": "^2.2.1",
-    "standard-version": "^9.1.0",
-    "webpack": "^5.22.0"
+    "standard-version": "^9.1.1",
+    "webpack": "^5.24.2"
   },
   "keywords": [
     "webpack",

src/index.js

@@ -1,20 +1,19 @@
 import Module from "module";
+import { pathToFileURL } from "url";
 
 import schema from "./options.json";
 
 const parentModule = module;
 
-function exec(code, loaderContext) {
-  const { resource, context } = loaderContext;
-
-  const module = new Module(resource, parentModule);
+function execute(code, loaderContext) {
+  const module = new Module(loaderContext.resource, parentModule);
 
   // eslint-disable-next-line no-underscore-dangle
-  module.paths = Module._nodeModulePaths(context);
-  module.filename = resource;
+  module.paths = Module._nodeModulePaths(loaderContext.context);
+  module.filename = loaderContext.resource;
 
   // eslint-disable-next-line no-underscore-dangle
-  module._compile(code, resource);
+  module._compile(code, loaderContext.resource);
 
   return module.exports;
 }
@@ -67,7 +66,7 @@ function processResult(loaderContext, result) {
   );
 }
 
-export default function loader(content) {
+export default async function loader(content) {
   const options = this.getOptions(schema);
   const { executableFile } = options;
   const callback = this.async();
@@ -78,15 +77,40 @@ export default function loader(content) {
     try {
       // eslint-disable-next-line global-require,import/no-dynamic-require
       exports = require(executableFile);
-    } catch (error) {
-      callback(new Error(`Unable to require "${executableFile}": ${error}`));
-      return;
+    } catch (requireError) {
+      try {
+        let importESM;
+
+        try {
+          // eslint-disable-next-line no-new-func
+          importESM = new Function("id", "return import(id);");
+        } catch (e) {
+          importESM = null;
+        }
+
+        if (
+          requireError.code === "ERR_REQUIRE_ESM" &&
+          pathToFileURL &&
+          importESM
+        ) {
+          const urlForConfig = pathToFileURL(executableFile);
+
+          exports = await importESM(urlForConfig);
+        } else {
+          throw requireError;
+        }
+      } catch (error) {
+        callback(new Error(`Unable to require "${executableFile}": ${error}`));
+
+        return;
+      }
     }
   } else {
     try {
-      exports = exec(content, this);
+      exports = execute(content, this);
     } catch (error) {
       callback(new Error(`Unable to execute "${this.resource}": ${error}`));
+
       return;
     }
   }

test/__snapshots__/executableFile.test.js.snap

@@ -10,9 +10,9 @@ Error: Unable to require \\"/test/fixtures/error-require.js\\": Error: This is a
 
 exports[`executableFile option should emit error: warnings 1`] = `Array []`;
 
-exports[`executableFile option should work: errors 1`] = `Array []`;
+exports[`executableFile option should work with commonjs format: errors 1`] = `Array []`;
 
-exports[`executableFile option should work: result 1`] = `
+exports[`executableFile option should work with commonjs format: result 1`] = `
 "{
   \\"content\\": \\"module.exports = 315360000000\\",
   \\"map\\": null,
@@ -25,4 +25,4 @@ exports[`executableFile option should work: result 1`] = `
 }"
 `;
 
-exports[`executableFile option should work: warnings 1`] = `Array []`;
+exports[`executableFile option should work with commonjs format: warnings 1`] = `Array []`;

test/__snapshots__/loader.test.js.snap

@@ -388,6 +388,27 @@ exports[`loader should work the same if a promise is returned: result 1`] = `
 
 exports[`loader should work the same if a promise is returned: warnings 1`] = `Array []`;
 
+exports[`loader should work with ES modules code: errors 1`] = `Array []`;
+
+exports[`loader should work with ES modules code: result 1`] = `
+"{
+  \\"content\\": \\"module.exports = \\\\\\"hello world\\\\\\";\\",
+  \\"map\\": {
+    \\"isASourceMap\\": true
+  },
+  \\"meta\\": {
+    \\"isAnAst\\": true
+  },
+  \\"dependencies\\": [
+    \\"test/fixtures/code-commonjs.js\\"
+  ],
+  \\"contextDependencies\\": [],
+  \\"buildDependencies\\": []
+}"
+`;
+
+exports[`loader should work with ES modules code: warnings 1`] = `Array []`;
+
 exports[`loader should work with async function: errors 1`] = `Array []`;
 
 exports[`loader should work with async function: result 1`] = `
@@ -408,3 +429,24 @@ exports[`loader should work with async function: result 1`] = `
 `;
 
 exports[`loader should work with async function: warnings 1`] = `Array []`;
+
+exports[`loader should work with commonjs code: errors 1`] = `Array []`;
+
+exports[`loader should work with commonjs code: result 1`] = `
+"{
+  \\"content\\": \\"export default \\\\\\"hello world\\\\\\";\\",
+  \\"map\\": {
+    \\"isASourceMap\\": true
+  },
+  \\"meta\\": {
+    \\"isAnAst\\": true
+  },
+  \\"dependencies\\": [
+    \\"test/fixtures/code-es.js\\"
+  ],
+  \\"contextDependencies\\": [],
+  \\"buildDependencies\\": []
+}"
+`;
+
+exports[`loader should work with commonjs code: warnings 1`] = `Array []`;

test/executableFile.test.js

@@ -3,7 +3,7 @@ import path from "path";
 import { getCompiler, compile, readAsset, normalizeErrors } from "./helpers";
 
 describe("executableFile option", () => {
-  it("should work", async () => {
+  it("should work with commonjs format", async () => {
     const compiler = getCompiler(
       "executableFileEntry.js",
       {},
@@ -47,6 +47,51 @@ describe("executableFile option", () => {
     expect(normalizeErrors(stats.compilation.errors)).toMatchSnapshot("errors");
   });
 
+  // TODO jest have not good support for ES modules for testing it, tested manually
+  it.skip("should work with ES modules format", async () => {
+    const compiler = getCompiler(
+      "executableFileEntry.js",
+      {},
+      {
+        module: {
+          rules: [
+            {
+              test: /\.(json)$/i,
+              rules: [
+                {
+                  loader: require.resolve("./helpers/helperLoader.js"),
+                },
+                {
+                  loader: require.resolve("../src"),
+                  options: {
+                    executableFile: path.resolve(
+                      __dirname,
+                      "fixtures",
+                      "executableFileES.mjs"
+                    ),
+                  },
+                },
+              ],
+            },
+            {
+              test: /\.json$/i,
+              type: "asset/resource",
+            },
+          ],
+        },
+      }
+    );
+    const stats = await compile(compiler);
+
+    expect(readAsset("val-loader.js", compiler, stats)).toMatchSnapshot(
+      "result"
+    );
+    expect(normalizeErrors(stats.compilation.warnings)).toMatchSnapshot(
+      "warnings"
+    );
+    expect(normalizeErrors(stats.compilation.errors)).toMatchSnapshot("errors");
+  });
+
   it("should emit error", async () => {
     const compiler = getCompiler(
       "executableFileEntry.js",

test/fixtures/code-commonjs.js

@@ -0,0 +1,9 @@
+function codeES() {
+  return {
+    code: 'module.exports = "hello world";',
+    sourceMap: { isASourceMap: true },
+    ast: { isAnAst: true },
+  };
+}
+
+module.exports = codeES;

test/fixtures/code-es.js

@@ -0,0 +1,9 @@
+function codeES() {
+  return {
+    code: 'export default "hello world";',
+    sourceMap: { isASourceMap: true },
+    ast: { isAnAst: true },
+  };
+}
+
+module.exports = codeES;

test/fixtures/executableFileES.mjs

@@ -0,0 +1,9 @@
+export default function yearsInMs(options, loaderContext, content) {
+  const {years} = JSON.parse(content);
+  const value = years * 365 * 24 * 60 * 60 * 1000;
+
+  return {
+    cacheable: true,
+    code: "export default " + value,
+  };
+};

test/loader.test.js

@@ -312,4 +312,30 @@ describe("loader", () => {
     );
     expect(normalizeErrors(stats.compilation.errors)).toMatchSnapshot("errors");
   });
+
+  it("should work with commonjs code", async () => {
+    const compiler = getCompiler("code-es.js");
+    const stats = await compile(compiler);
+
+    expect(readAsset("val-loader.js", compiler, stats)).toMatchSnapshot(
+      "result"
+    );
+    expect(normalizeErrors(stats.compilation.warnings)).toMatchSnapshot(
+      "warnings"
+    );
+    expect(normalizeErrors(stats.compilation.errors)).toMatchSnapshot("errors");
+  });
+
+  it("should work with ES modules code", async () => {
+    const compiler = getCompiler("code-commonjs.js");
+    const stats = await compile(compiler);
+
+    expect(readAsset("val-loader.js", compiler, stats)).toMatchSnapshot(
+      "result"
+    );
+    expect(normalizeErrors(stats.compilation.warnings)).toMatchSnapshot(
+      "warnings"
+    );
+    expect(normalizeErrors(stats.compilation.errors)).toMatchSnapshot("errors");
+  });
 });