feat(cacheDir): add caching independent of webpack's caching

.cspell.json

@@ -43,7 +43,8 @@
     "libvips",
     "hspace",
     "commitlint",
-    "nodenext"
+    "nodenext",
+    "eslintcache"
   ],
 
   "ignorePaths": [

.gitignore

@@ -1,4 +1,5 @@
 node_modules
+.cache
 coverage
 .vscode
 logs

README.md

@@ -40,6 +40,7 @@ with option `"markdown.extension.toc.levels": "2..6"`
 - [Plugin Options](#plugin-options)
   - [`test`](#test)
   - [`include`](#include)
+  - [`cacheDir`](#cachedir)
   - [`exclude`](#exclude)
   - [`minimizer`](#minimizer)
     - [Available minimizers](#available-minimizers)
@@ -76,6 +77,7 @@ with option `"markdown.extension.toc.levels": "2..6"`
   - [`generator`](#generator-1)
     - [Loader generator example for `imagemin`](#loader-generator-example-for-imagemin)
   - [`severityError`](#severityerror-1)
+  - [`cacheDir`](#cachedir-1)
 - [Additional API](#additional-api)
   - [`imageminNormalizeConfig(config)`](#imageminnormalizeconfigconfig)
 - [Examples](#examples)
@@ -699,6 +701,64 @@ module.exports = {
 };
 ```
 
+### `cacheDir`
+
+Type:
+
+```ts
+type cacheDir = string;
+```
+
+Default: `undefined`
+
+If provided, ensures all image transformations are done only once and cached within this folder. (Sharp only)
+
+**webpack.config.js**
+
+```js
+const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");
+
+module.exports = {
+  optimization: {
+    minimizer: [
+      "...",
+      new ImageMinimizerPlugin({
+        cacheDir: ".cache/image-minimizer",
+      }),
+    ],
+  },
+};
+```
+
+### `bypassWebpackCache`
+
+Type:
+
+```ts
+type bypassWebpackCache = string;
+```
+
+Default: `undefined`
+
+If `true`, skips using Webpack's cache. (Typically useful if you're using the `cacheDir` and therefore don't need to double-up on caching with Webpack's cache.)
+
+**webpack.config.js**
+
+```js
+const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");
+
+module.exports = {
+  optimization: {
+    minimizer: [
+      "...",
+      new ImageMinimizerPlugin({
+        bypassWebpackCache: true,
+      }),
+    ],
+  },
+};
+```
+
 ### `minimizer`
 
 Type:
@@ -2356,6 +2416,49 @@ module.exports = {
 };
 ```
 
+### `cacheDir`
+
+Type:
+
+```ts
+type cacheDir = string;
+```
+
+Default: `undefined`
+
+If provided, ensures all image transformations are done only once and cached within this folder. (Sharp only)
+
+**webpack.config.js**
+
+```js
+const ImageMinimizerPlugin = require("image-minimizer-webpack-plugin");
+
+module.exports = {
+  module: {
+    rules: [
+      {
+        test: /\.(jpe?g|png|gif|svg)$/i,
+        type: "asset",
+      },
+      {
+        test: /\.(jpe?g|png|gif|svg)$/i,
+        use: [
+          {
+            loader: ImageMinimizerPlugin.loader,
+            options: {
+              cacheDir: ".cache/image-minimizer",
+              minimizerOptions: {
+                plugins: ["gifsicle"],
+              },
+            },
+          },
+        ],
+      },
+    ],
+  },
+};
+```
+
 ## Additional API
 
 ### `imageminNormalizeConfig(config)`

package.json

@@ -17,12 +17,15 @@
     "node": ">= 18.12.0"
   },
   "scripts": {
-    "start": "npm run build -- -w",
+    "start": "npm-run-all -p \"watch:**\"",
     "clean": "del-cli dist types",
     "prebuild": "npm run clean",
-    "build:types": "tsc --declaration --emitDeclarationOnly && prettier \"types/**/*.ts\" --write",
+    "build:types": "tsc --declaration --emitDeclarationOnly",
+    "postbuild:types": "prettier \"types/**/*.ts\" --write",
     "build:code": "cross-env NODE_ENV=production babel src -d dist --copy-files",
     "build": "npm-run-all -p \"build:**\"",
+    "watch:types": "npm run build:types -- -w",
+    "watch:code": "npm run build:code -- -w",
     "commitlint": "commitlint --from=master",
     "security": "npm audit --production",
     "lint:prettier": "prettier --cache --list-different .",
@@ -69,8 +72,12 @@
     }
   },
   "dependencies": {
+    "graceful-fs": "^4.2.11",
+    "mkdirp": "^3.0.1",
+    "proper-lockfile": "^4.1.2",
     "schema-utils": "^4.2.0",
-    "serialize-javascript": "^6.0.2"
+    "serialize-javascript": "^6.0.2",
+    "stream-buffers": "^3.0.3"
   },
   "devDependencies": {
     "@babel/cli": "^7.24.7",
@@ -79,10 +86,13 @@
     "@commitlint/cli": "^19.3.0",
     "@commitlint/config-conventional": "^19.2.2",
     "@squoosh/lib": "^0.5.3",
+    "@types/graceful-fs": "^4.1.9",
     "@types/imagemin": "^9.0.0",
     "@types/node": "^20.14.9",
+    "@types/proper-lockfile": "^4.1.4",
     "@types/serialize-javascript": "^5.0.4",
     "@types/sharp": "^0.32.0",
+    "@types/stream-buffers": "^3.0.7",
     "@webpack-contrib/eslint-config-webpack": "^3.0.0",
     "babel-jest": "^29.7.0",
     "copy-webpack-plugin": "^12.0.2",