feat: accept a precompiled check in the worker's getOptions

src/worker.js

@@ -210,7 +210,7 @@ const queue = asyncQueue(({ id, data }, taskCallback) => {
             }
           },
           // Not an arrow function because it uses this
-          getOptions(schema) {
+          getOptions(schema, check) {
             // loaders, loaderIndex will be defined by runLoaders
             const loader = this.loaders[this.loaderIndex];
 
@@ -240,7 +240,10 @@ const queue = asyncQueue(({ id, data }, taskCallback) => {
               options = {};
             }
 
-            if (schema) {
+            // A precompiled check that passes skips the schema, as webpack's own
+            // `getOptions` does; one that fails still gets the full validation
+            // and its error messages.
+            if (schema && !(typeof check === 'function' && check(options))) {
               let name = 'Loader';
               let baseDataPath = 'options';
               let match;

test/options-check.test.js

@@ -0,0 +1,57 @@
+import os from 'os';
+import path from 'path';
+
+import webpack from 'webpack';
+
+const threadLoader = require('../dist');
+
+const loader = require.resolve('./options-check/options-check-loader');
+
+const run = (options) =>
+  new Promise((resolve, reject) => {
+    webpack(
+      {
+        mode: 'none',
+        context: path.resolve(__dirname, 'options-check'),
+        devtool: false,
+        entry: './file.js',
+        output: {
+          path: path.join(os.tmpdir(), 'thread-loader-options-check'),
+        },
+        module: {
+          rules: [
+            {
+              test: /file\.js$/,
+              use: [
+                {
+                  loader: path.resolve(__dirname, '../dist/index.js'),
+                  options: { workers: 1, poolTimeout: 2000 },
+                },
+                { loader, options },
+              ],
+            },
+          ],
+        },
+      },
+      (err, stats) => (err ? reject(err) : resolve(stats)),
+    );
+  });
+
+beforeAll(() => {
+  threadLoader.warmup({ workers: 1, poolTimeout: 2000 }, [loader]);
+});
+
+test('skips the schema when the precompiled check passes', async () => {
+  const stats = await run({ trusted: true });
+
+  expect(stats.compilation.errors).toHaveLength(0);
+});
+
+test('validates against the schema when the precompiled check fails', async () => {
+  const stats = await run({ name: 1 });
+
+  expect(stats.compilation.errors).toHaveLength(1);
+  expect(stats.compilation.errors[0].message).toMatch(
+    /options\.name should be a string/,
+  );
+});

test/options-check/file.js

@@ -0,0 +1 @@
+module.exports = 'file';

test/options-check/options-check-loader.js

@@ -0,0 +1,11 @@
+const schema = {
+  type: 'object',
+  properties: { name: { type: 'string' } },
+  additionalProperties: false,
+};
+
+module.exports = function optionsCheckLoader() {
+  const options = this.getOptions(schema, (value) => value.trusted === true);
+
+  return `module.exports = ${JSON.stringify(options)};`;
+};