Add possibility to set watcher options and provide default aggregateTimeout

package.json

@@ -35,6 +35,7 @@
     },
     "devDependencies": {
         "@types/webpack": "*",
+        "@types/watchpack": "*",
         "prettier": "^2.4.1"
     }
 }

plugin.d.ts

@@ -1,4 +1,5 @@
 import { Compiler } from 'webpack'
+import { WatchOptions } from 'watchpack'
 
 export interface WasmPackPluginOptions {
     crateDirectory: string
@@ -9,6 +10,7 @@ export interface WasmPackPluginOptions {
     outDir?: string
     outName?: string
     watchDirectories?: string[]
+    watchOptions?: WatchOptions
     /** Controls plugin output verbosity. Defaults to 'info'. */
     pluginLogLevel?: 'info' | 'error'
 }

plugin.js

@@ -61,7 +61,11 @@ class WasmPackPlugin {
             info = () => {}
         }
 
-        this.wp = new Watchpack()
+        // May need to adjust this default since this is potentialy computation heavy
+        this.watchOptions = Object.assign(
+            { aggregateTimeout: 300 },
+            options.watchOptions
+        )
         this.isDebug = true
         this.error = null
     }
@@ -71,10 +75,18 @@ class WasmPackPlugin {
             ? this.forceMode === 'development'
             : compiler.options.mode === 'development'
 
+        this.watchOptions = Object.assign(
+            compiler.options.watchOptions,
+            this.watchOptions
+        )
+
         // This fixes an error in Webpack where it cannot find
         // the `pkg/index.js` file if Rust compilation errors.
         this._makeEmpty()
 
+        // Move Watchpack initialization here so we can pass watchOptions to it
+        this.wp = new Watchpack(this.watchOptions)
+
         // force first compilation
         compiler.hooks.beforeCompile.tapPromise('WasmPackPlugin', () => {
             if (this._ranInitialCompilation === true) {