feat: added ability to minimizer JSON using jsonMinify (#657)

Author: alexander-akait

README.md

@@ -815,6 +815,31 @@ module.exports = {
 };
 ```
 
+### JSON
+
+Uses `JSON.stringify()` to minify your JSON files during the build process.
+
+**webpack.config.js**
+
+```js
+module.exports = {
+  optimization: {
+    minimize: true,
+    minimizer: [
+      // Keeps original terser plugin to minify JS files
+      "...",
+      // Will minify JSON files (they can come from copy-webpack-plugin or when you are using asset modules)
+      new TerserPlugin({
+        test: /\.json$/,
+        minify: TerserPlugin.jsonMinify,
+        // We are supporting `space` and `replacer` options, you can set them below
+        terserOptions: {},
+      }),
+    ],
+  },
+};
+```
+
 ### Custom Minify Function
 
 Override the default minify function - use `uglify-js` for minification.

src/index.js

@@ -7,6 +7,7 @@ const { minify } = require("./minify");
 const schema = require("./options.json");
 const {
   esbuildMinify,
+  jsonMinify,
   memoize,
   swcMinify,
   terserMinify,
@@ -117,6 +118,7 @@ const {
  * @typedef {object} MinimizeFunctionHelpers
  * @property {() => string | undefined=} getMinimizerVersion function that returns version of minimizer
  * @property {() => boolean | undefined=} supportsWorkerThreads true when minimizer support worker threads, otherwise false
+ * @property {() => boolean | undefined=} supportsWorker true when minimizer support worker, otherwise false
  */
 
 /**
@@ -178,6 +180,7 @@ class TerserPlugin {
       baseDataPath: "options",
     });
 
+    // TODO handle json and etc in the next major release
     // TODO make `minimizer` option instead `minify` and `terserOptions` in the next major release, also rename `terserMinify` to `terserMinimize`
     const {
       minify = /** @type {MinimizerImplementation<T>} */ (terserMinify),
@@ -407,7 +410,15 @@ class TerserPlugin {
     /** @type {undefined | number} */
     let numberOfWorkers;
 
-    if (optimizeOptions.availableNumberOfCores > 0) {
+    const needCreateWorker =
+      optimizeOptions.availableNumberOfCores > 0 &&
+      (typeof this.options.minimizer.implementation.supportsWorker ===
+        "undefined" ||
+        (typeof this.options.minimizer.implementation.supportsWorker ===
+          "function" &&
+          this.options.minimizer.implementation.supportsWorker()));
+
+    if (needCreateWorker) {
       // Do not create unnecessary workers when the number of files is less than the available cores, it saves memory
       numberOfWorkers = Math.min(
         numberOfAssets,
@@ -908,5 +919,6 @@ TerserPlugin.terserMinify = terserMinify;
 TerserPlugin.uglifyJsMinify = uglifyJsMinify;
 TerserPlugin.swcMinify = swcMinify;
 TerserPlugin.esbuildMinify = esbuildMinify;
+TerserPlugin.jsonMinify = jsonMinify;
 
 module.exports = TerserPlugin;

src/utils.js

@@ -775,6 +775,32 @@ esbuildMinify.getMinimizerVersion = () => {
  */
 esbuildMinify.supportsWorkerThreads = () => false;
 
+/* istanbul ignore next */
+/**
+ * @param {Input} input input
+ * @param {RawSourceMap=} sourceMap source map
+ * @param {CustomOptions=} minimizerOptions options
+ * @returns {Promise<MinimizedResult>} minimized result
+ */
+async function jsonMinify(input, sourceMap, minimizerOptions) {
+  const options =
+    /** @type {{ replacer?: Parameters<typeof JSON.stringify>[1], space?: Parameters<typeof JSON.stringify>[2] }} */
+    (minimizerOptions);
+
+  const [[, code]] = Object.entries(input);
+  const result = JSON.stringify(
+    JSON.parse(code),
+    options.replacer,
+    options.space,
+  );
+
+  return { code: result };
+}
+
+jsonMinify.getMinimizerVersion = () => "1.0.0";
+jsonMinify.supportsWorker = () => false;
+jsonMinify.supportsWorkerThreads = () => false;
+
 /**
  * @template T
  * @typedef {() => T} FunctionReturning
@@ -806,6 +832,7 @@ function memoize(fn) {
 
 module.exports = {
   esbuildMinify,
+  jsonMinify,
   memoize,
   swcMinify,
   terserMinify,

test/__snapshots__/minify-option.test.js.snap

@@ -148,6 +148,35 @@ exports[`minify option should work using when the \`minify\` option is \`esbuild
 
 exports[`minify option should work using when the \`minify\` option is \`esbuildMinify\`: warnings 1`] = `Array []`;
 
+exports[`minify option should work using when the \`minify\` option is \`jsonMinify\` and allows to set \`JSON.stringify\` options: assets 1`] = `
+Object {
+  "71be2c5d019f14d29bdd.json": "{
+    \\"foo\\": \\"bar\\",
+    \\"bar\\": [
+        \\"baz\\"
+    ]
+}",
+  "main.js": "(()=>{var t={437(t,r,e){\\"use strict\\";t.exports=e.p+\\"71be2c5d019f14d29bdd.json\\"}},r={};function e(o){var n=r[o];if(void 0!==n)return n.exports;var c=r[o]={exports:{}};return t[o](c,c.exports,e),c.exports}e.m=t,e.g=function(){if(\\"object\\"==typeof globalThis)return globalThis;try{return this||new Function(\\"return this\\")()}catch(t){if(\\"object\\"==typeof window)return window}}(),e.o=(t,r)=>Object.prototype.hasOwnProperty.call(t,r),(()=>{var t;e.g.importScripts&&(t=e.g.location+\\"\\");var r=e.g.document;if(!t&&r&&(r.currentScript&&\\"SCRIPT\\"===r.currentScript.tagName.toUpperCase()&&(t=r.currentScript.src),!t)){var o=r.getElementsByTagName(\\"script\\");if(o.length)for(var n=o.length-1;n>-1&&(!t||!/^http(s?):/.test(t));)t=o[n--].src}if(!t)throw new Error(\\"Automatic publicPath is not supported in this browser\\");t=t.replace(/^blob:/,\\"\\").replace(/#.*$/,\\"\\").replace(/\\\\?.*$/,\\"\\").replace(/\\\\/[^\\\\/]+$/,\\"/\\"),e.p=t})(),e.b=\\"undefined\\"!=typeof document&&document.baseURI||self.location.href,console.log(new URL(e(437),e.b))})();",
+}
+`;
+
+exports[`minify option should work using when the \`minify\` option is \`jsonMinify\` and allows to set \`JSON.stringify\` options: errors 1`] = `Array []`;
+
+exports[`minify option should work using when the \`minify\` option is \`jsonMinify\` and allows to set \`JSON.stringify\` options: warnings 1`] = `Array []`;
+
+exports[`minify option should work using when the \`minify\` option is \`jsonMinify\` and output errors: warnings 1`] = `Array []`;
+
+exports[`minify option should work using when the \`minify\` option is \`jsonMinify\`: assets 1`] = `
+Object {
+  "60491a50c1e5dd7216b6.json": "{\\"foo\\":\\"bar\\",\\"bar\\":[\\"baz\\"]}",
+  "main.js": "(()=>{var t={437(t,r,e){\\"use strict\\";t.exports=e.p+\\"60491a50c1e5dd7216b6.json\\"}},r={};function e(o){var n=r[o];if(void 0!==n)return n.exports;var c=r[o]={exports:{}};return t[o](c,c.exports,e),c.exports}e.m=t,e.g=function(){if(\\"object\\"==typeof globalThis)return globalThis;try{return this||new Function(\\"return this\\")()}catch(t){if(\\"object\\"==typeof window)return window}}(),e.o=(t,r)=>Object.prototype.hasOwnProperty.call(t,r),(()=>{var t;e.g.importScripts&&(t=e.g.location+\\"\\");var r=e.g.document;if(!t&&r&&(r.currentScript&&\\"SCRIPT\\"===r.currentScript.tagName.toUpperCase()&&(t=r.currentScript.src),!t)){var o=r.getElementsByTagName(\\"script\\");if(o.length)for(var n=o.length-1;n>-1&&(!t||!/^http(s?):/.test(t));)t=o[n--].src}if(!t)throw new Error(\\"Automatic publicPath is not supported in this browser\\");t=t.replace(/^blob:/,\\"\\").replace(/#.*$/,\\"\\").replace(/\\\\?.*$/,\\"\\").replace(/\\\\/[^\\\\/]+$/,\\"/\\"),e.p=t})(),e.b=\\"undefined\\"!=typeof document&&document.baseURI||self.location.href,console.log(new URL(e(437),e.b))})();",
+}
+`;
+
+exports[`minify option should work using when the \`minify\` option is \`jsonMinify\`: errors 1`] = `Array []`;
+
+exports[`minify option should work using when the \`minify\` option is \`jsonMinify\`: warnings 1`] = `Array []`;
+
 exports[`minify option should work using when the \`minify\` option is \`swcMinify\` and ECMA modules output: assets 1`] = `
 Object {
   "main.js": "var e={};e.d=(o,t)=>{for(var r in t)e.o(t,r)&&!e.o(o,r)&&Object.defineProperty(o,r,{enumerable:!0,get:t[r]})},e.o=(e,o)=>Object.prototype.hasOwnProperty.call(e,o);var o={};function t(){console.log(11)}e.d(o,{A:()=>r}),t();let r=t,a=o.A;export{a as default};",

test/fixtures/file-error.json

@@ -0,0 +1,3 @@
+{
+  "foo":
+}

test/fixtures/file.json

@@ -0,0 +1,7 @@
+{
+  "foo":
+
+    "bar",
+
+  "bar": [ "baz" ]
+}

test/fixtures/json-error.js

@@ -0,0 +1 @@
+console.log(new URL("./file-error.json", import.meta.url));

test/fixtures/json.js

@@ -0,0 +1 @@
+console.log(new URL("./file.json", import.meta.url));

test/minify-option.test.js

@@ -819,6 +819,60 @@ describe("minify option", () => {
     expect(getWarnings(stats)).toMatchSnapshot("warnings");
   });
 
+  it("should work using when the `minify` option is `jsonMinify`", async () => {
+    const compiler = getCompiler({
+      entry: path.resolve(__dirname, "./fixtures/json.js"),
+    });
+
+    new TerserPlugin().apply(compiler);
+    new TerserPlugin({
+      test: /\.json$/i,
+      minify: TerserPlugin.jsonMinify,
+    }).apply(compiler);
+
+    const stats = await compile(compiler);
+
+    expect(readsAssets(compiler, stats)).toMatchSnapshot("assets");
+    expect(getErrors(stats)).toMatchSnapshot("errors");
+    expect(getWarnings(stats)).toMatchSnapshot("warnings");
+  });
+
+  it("should work using when the `minify` option is `jsonMinify` and allows to set `JSON.stringify` options", async () => {
+    const compiler = getCompiler({
+      entry: path.resolve(__dirname, "./fixtures/json.js"),
+    });
+
+    new TerserPlugin().apply(compiler);
+    new TerserPlugin({
+      test: /\.json$/i,
+      minify: TerserPlugin.jsonMinify,
+      terserOptions: { space: 4, replacer: null },
+    }).apply(compiler);
+
+    const stats = await compile(compiler);
+
+    expect(readsAssets(compiler, stats)).toMatchSnapshot("assets");
+    expect(getErrors(stats)).toMatchSnapshot("errors");
+    expect(getWarnings(stats)).toMatchSnapshot("warnings");
+  });
+
+  it("should work using when the `minify` option is `jsonMinify` and output errors", async () => {
+    const compiler = getCompiler({
+      entry: path.resolve(__dirname, "./fixtures/json-error.js"),
+    });
+
+    new TerserPlugin().apply(compiler);
+    new TerserPlugin({
+      test: /\.json$/i,
+      minify: TerserPlugin.jsonMinify,
+    }).apply(compiler);
+
+    const stats = await compile(compiler);
+
+    expect(stats.compilation.errors[0].message).toContain("Unexpected token");
+    expect(getWarnings(stats)).toMatchSnapshot("warnings");
+  });
+
   // Due `esbuild` doesn't support extract comments we keep legal comments by default
   it("should work using when the `minify` option is `esbuildMinify` and keep legal comments when extract comments is disabled", async () => {
     const compiler = getCompiler({

types/index.d.ts

@@ -71,6 +71,7 @@ declare namespace TerserPlugin {
     uglifyJsMinify,
     swcMinify,
     esbuildMinify,
+    jsonMinify,
     Schema,
     Compiler,
     Compilation,
@@ -112,6 +113,7 @@ import { terserMinify } from "./utils";
 import { uglifyJsMinify } from "./utils";
 import { swcMinify } from "./utils";
 import { esbuildMinify } from "./utils";
+import { jsonMinify } from "./utils";
 type Schema = import("schema-utils/declarations/validate").Schema;
 type Compiler = import("webpack").Compiler;
 type Compilation = import("webpack").Compilation;
@@ -250,6 +252,10 @@ type MinimizeFunctionHelpers = {
    * true when minimizer support worker threads, otherwise false
    */
   supportsWorkerThreads?: (() => boolean | undefined) | undefined;
+  /**
+   * true when minimizer support worker, otherwise false
+   */
+  supportsWorker?: (() => boolean | undefined) | undefined;
 };
 type MinimizerImplementation<T> = BasicMinimizerImplementation<T> &
   MinimizeFunctionHelpers;