feat: added the executableFile option (#65)

README.md

@@ -71,6 +71,71 @@ const answer = require("target-file");
 
 And run `webpack` via your preferred method.
 
+## Options
+
+|                  Name                   |    Type    |   Default   | Description                                   |
+| :-------------------------------------: | :--------: | :---------: | :-------------------------------------------- |
+| **[`executableFile`](#executableFile)** | `{String}` | `undefined` | Allows to specify path to the executable file |
+
+### executableFile
+
+Type: `String`
+Default: `undefined`
+
+Allows to specify path to the executable file
+
+**data.json**
+
+```json
+{
+  "years": "10"
+}
+```
+
+**executable-file.js**
+
+```js
+module.exports = function yearsInMs(options, loaderContext, content) {
+  const { years } = JSON.parse(content);
+  const value = years * 365 * 24 * 60 * 60 * 1000;
+
+  return {
+    cacheable: true,
+    code: "module.exports = " + value,
+  };
+};
+```
+
+**webpack.config.js**
+
+```js
+module.exports = {
+  module: {
+    rules: [
+      {
+        test: /\.(json)$/i,
+        rules: [
+          {
+            loader: "val-loader",
+            options: {
+              executableFile: path.resolve(
+                __dirname,
+                "fixtures",
+                "executableFile.js"
+              ),
+            },
+          },
+        ],
+      },
+      {
+        test: /\.json$/i,
+        type: "asset/resource",
+      },
+    ],
+  },
+};
+```
+
 ## Return Object Properties
 
 Targeted modules of this loader must export a `Function` that returns an object,

src/index.js

@@ -69,34 +69,49 @@ function processResult(loaderContext, result) {
 
 export default function loader(content) {
   const options = this.getOptions(schema);
+  const { executableFile } = options;
+  const callback = this.async();
 
   let exports;
 
-  try {
-    exports = exec(content, this);
-  } catch (error) {
-    throw new Error(`Unable to execute "${this.resource}": ${error}`);
+  if (executableFile) {
+    try {
+      // eslint-disable-next-line global-require,import/no-dynamic-require
+      exports = require(executableFile);
+    } catch (error) {
+      callback(new Error(`Unable to require "${executableFile}": ${error}`));
+      return;
+    }
+  } else {
+    try {
+      exports = exec(content, this);
+    } catch (error) {
+      callback(new Error(`Unable to execute "${this.resource}": ${error}`));
+      return;
+    }
   }
 
   const func = exports && exports.default ? exports.default : exports;
 
   if (typeof func !== "function") {
-    throw new Error(
-      `Module "${this.resource}" does not export a function as default`
+    callback(
+      new Error(
+        `Module "${this.resource}" does not export a function as default`
+      )
     );
+    return;
   }
 
   let result;
 
   try {
-    result = func(options, this);
+    result = func(options, this, content);
   } catch (error) {
-    throw new Error(`Module "${this.resource}" throw error: ${error}`);
+    callback(new Error(`Module "${this.resource}" throw error: ${error}`));
+    return;
   }
 
   if (result && typeof result.then === "function") {
-    const callback = this.async();
-
     result
       .then((res) => processResult(this, res))
       .catch((error) => {

test/__snapshots__/executableFile.test.js.snap

@@ -0,0 +1,28 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`executableFile option should emit error: errors 1`] = `
+Array [
+  "ModuleBuildError: Module build failed (from \`replaced original path\`):
+Error: Unable to require \\"/test/fixtures/error-require.js\\": Error: This is a typical require() error",
+  "ChunkRenderError: Cannot read property 'get' of undefined",
+]
+`;
+
+exports[`executableFile option should emit error: warnings 1`] = `Array []`;
+
+exports[`executableFile option should work: errors 1`] = `Array []`;
+
+exports[`executableFile option should work: result 1`] = `
+"{
+  \\"content\\": \\"module.exports = 315360000000\\",
+  \\"map\\": null,
+  \\"meta\\": null,
+  \\"dependencies\\": [
+    \\"test/fixtures/data.json\\"
+  ],
+  \\"contextDependencies\\": [],
+  \\"buildDependencies\\": []
+}"
+`;
+
+exports[`executableFile option should work: warnings 1`] = `Array []`;

test/executableFile.test.js

@@ -0,0 +1,90 @@
+import path from "path";
+
+import { getCompiler, compile, readAsset, normalizeErrors } from "./helpers";
+
+describe("executableFile option", () => {
+  it("should work", async () => {
+    const compiler = getCompiler(
+      "executableFileEntry.js",
+      {},
+      {
+        module: {
+          rules: [
+            {
+              test: /\.(json)$/i,
+              rules: [
+                {
+                  loader: require.resolve("./helpers/helperLoader.js"),
+                },
+                {
+                  loader: require.resolve("../src"),
+                  options: {
+                    executableFile: path.resolve(
+                      __dirname,
+                      "fixtures",
+                      "executableFile.js"
+                    ),
+                  },
+                },
+              ],
+            },
+            {
+              test: /\.json$/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",
+      {},
+      {
+        module: {
+          rules: [
+            {
+              test: /\.(json)$/i,
+              rules: [
+                {
+                  loader: require.resolve("./helpers/helperLoader.js"),
+                },
+                {
+                  loader: require.resolve("../src"),
+                  options: {
+                    executableFile: path.resolve(
+                      __dirname,
+                      "fixtures",
+                      "error-require.js"
+                    ),
+                  },
+                },
+              ],
+            },
+            {
+              test: /\.json$/i,
+              type: "asset/resource",
+            },
+          ],
+        },
+      }
+    );
+    const stats = await compile(compiler);
+
+    expect(normalizeErrors(stats.compilation.warnings)).toMatchSnapshot(
+      "warnings"
+    );
+    expect(normalizeErrors(stats.compilation.errors)).toMatchSnapshot("errors");
+  });
+});

test/fixtures/data.json

@@ -0,0 +1,3 @@
+{
+  "years": "10"
+}

test/fixtures/executableFile.js

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

test/fixtures/executableFileEntry.js

@@ -0,0 +1,3 @@
+const data = require('./data.json');
+
+module.exports = {data};