fix: use finishModules if thread is less than or equal 1 (#95)

Author: ricardogobbosouza

src/index.js

@@ -88,9 +88,11 @@ class ESLintWebpackPlugin {
       let lint;
       /** @type {import('./linter').Reporter} */
       let report;
+      /** @type number */
+      let threads;
 
       try {
-        ({ lint, report } = linter(this.key, options, compilation));
+        ({ lint, report, threads } = linter(this.key, options, compilation));
       } catch (e) {
         compilation.errors.push(e);
         return;
@@ -112,13 +114,17 @@ class ESLintWebpackPlugin {
             !isMatch(file, exclude, { dot: true })
           ) {
             files.push(file);
+
+            if (threads > 1) {
+              lint(file);
+            }
           }
         }
       });
 
       // Lint all files added
       compilation.hooks.finishModules.tap(this.key, () => {
-        if (files.length > 0) {
+        if (files.length > 0 && threads <= 1) {
           lint(files);
         }
       });

src/linter.js

@@ -24,7 +24,7 @@ const resultStorage = new WeakMap();
  * @param {string|undefined} key
  * @param {Options} options
  * @param {Compilation} compilation
- * @returns {{lint: Linter, report: Reporter}}
+ * @returns {{lint: Linter, report: Reporter, threads: number}}
  */
 export default function linter(key, options, compilation) {
   /** @type {ESLint} */
@@ -36,20 +36,24 @@ export default function linter(key, options, compilation) {
   /** @type {() => Promise<void>} */
   let cleanup;
 
+  /** @type number */
+  let threads;
+
   /** @type {Promise<LintResult[]>[]} */
   const rawResults = [];
 
   const crossRunResultStorage = getResultStorage(compilation);
 
   try {
-    ({ eslint, lintFiles, cleanup } = getESLint(key, options));
+    ({ eslint, lintFiles, cleanup, threads } = getESLint(key, options));
   } catch (e) {
     throw new ESLintError(e.message);
   }
 
   return {
     lint,
     report,
+    threads,
   };
 
   /**