perf: parse options only one time (#122)

Author: ricardogobbosouza

declarations/index.d.ts

@@ -10,8 +10,16 @@ declare class ESLintWebpackPlugin {
   options: import('./options').PluginOptions;
   /**
    * @param {Compiler} compiler
+   * @param {Options} options
+   * @param {string[]} wanted
+   * @param {string[]} exclude
    */
-  run(compiler: Compiler): Promise<void>;
+  run(
+    compiler: Compiler,
+    options: Options,
+    wanted: string[],
+    exclude: string[]
+  ): Promise<void>;
   /**
    * @param {Compiler} compiler
    * @returns {void}

src/index.js

@@ -31,10 +31,28 @@ class ESLintWebpackPlugin {
     // this differentiates one from the other when being cached.
     this.key = compiler.name || `${this.key}_${(counter += 1)}`;
 
+    const options = {
+      ...this.options,
+      exclude: parseFiles(
+        this.options.exclude || [],
+        this.getContext(compiler)
+      ),
+      extensions: arrify(this.options.extensions),
+      files: parseFiles(this.options.files || '', this.getContext(compiler)),
+    };
+
+    const wanted = parseFoldersToGlobs(options.files, options.extensions);
+    const exclude = parseFoldersToGlobs(
+      this.options.exclude ? options.exclude : '**/node_modules/**',
+      []
+    );
+
     // If `lintDirtyModulesOnly` is disabled,
     // execute the linter on the build
     if (!this.options.lintDirtyModulesOnly) {
-      compiler.hooks.run.tapPromise(this.key, this.run);
+      compiler.hooks.run.tapPromise(this.key, (c) =>
+        this.run(c, options, wanted, exclude)
+      );
     }
 
     let isFirstRun = this.options.lintDirtyModulesOnly;
@@ -45,14 +63,17 @@ class ESLintWebpackPlugin {
         return Promise.resolve();
       }
 
-      return this.run(c);
+      return this.run(c, options, wanted, exclude);
     });
   }
 
   /**
    * @param {Compiler} compiler
+   * @param {Options} options
+   * @param {string[]} wanted
+   * @param {string[]} exclude
    */
-  async run(compiler) {
+  async run(compiler, options, wanted, exclude) {
     // Do not re-hook
     if (
       // @ts-ignore
@@ -61,22 +82,6 @@ class ESLintWebpackPlugin {
       return;
     }
 
-    const options = {
-      ...this.options,
-      exclude: parseFiles(
-        this.options.exclude || [],
-        this.getContext(compiler)
-      ),
-      extensions: arrify(this.options.extensions),
-      files: parseFiles(this.options.files || '', this.getContext(compiler)),
-    };
-
-    const wanted = parseFoldersToGlobs(options.files, options.extensions);
-    const exclude = parseFoldersToGlobs(
-      this.options.exclude ? options.exclude : '**/node_modules/**',
-      []
-    );
-
     compiler.hooks.thisCompilation.tap(this.key, (compilation) => {
       /** @type {import('./linter').Linter} */
       let lint;

src/utils.js

@@ -19,6 +19,7 @@ import normalizePath from 'normalize-path';
            : [T]
  }
  */
+/* istanbul ignore next */
 export function arrify(value) {
   // eslint-disable-next-line no-undefined
   if (value === null || value === undefined) {