Allow to pass not string values to worker

index.js

@@ -1,16 +1,19 @@
 const { codeFrameColumns } = require("@babel/code-frame");
 const Worker = require("jest-worker").default;
+const serialize = require("serialize-javascript");
 
 function uglify(userOptions = {}) {
   if (userOptions.sourceMap != null) {
     throw Error("sourceMap option is removed, use sourcemap instead");
   }
 
-  const minifierOptions = Object.assign({}, userOptions, {
-    sourceMap: userOptions.sourcemap !== false,
-    sourcemap: undefined,
-    numWorkers: undefined
-  });
+  const minifierOptions = serialize(
+    Object.assign({}, userOptions, {
+      sourceMap: userOptions.sourcemap !== false,
+      sourcemap: undefined,
+      numWorkers: undefined
+    })
+  );
 
   return {
     name: "uglify",

package.json

@@ -26,6 +26,7 @@
   "dependencies": {
     "@babel/code-frame": "^7.0.0",
     "jest-worker": "^23.2.0",
+    "serialize-javascript": "^1.5.0",
     "uglify-js": "^3.4.9"
   },
   "peerDependencies": {

test/test.js

@@ -90,3 +90,14 @@ test("works with code splitting", async () => {
   });
   expect(newOutput).toMatchSnapshot();
 });
+
+test("allow to pass not string values to worker", async () => {
+  const bundle = await rollup({
+    input: "test/fixtures/unminified.js",
+    plugins: [uglify({ mangle: { properties: { regex: /^_/ } } })]
+  });
+  const result = await bundle.generate({ format: "cjs" });
+  expect(result.code).toEqual(
+    '"use strict";window.a=5,window.a<3&&console.log(4);\n'
+  );
+});

transform.js

@@ -1,6 +1,7 @@
 const { minify } = require("uglify-js");
 
-const transform = (code, options) => {
+const transform = (code, optionsString) => {
+  const options = eval(`(${optionsString})`)
   const result = minify(code, options);
   if (result.error) {
     throw result.error;

yarn.lock

@@ -3115,6 +3115,10 @@ semver@^5.5.0:
   version "5.5.1"
   resolved "https://registry.yarnpkg.com/semver/-/semver-5.5.1.tgz#7dfdd8814bdb7cabc7be0fb1d734cfb66c940477"
 
+serialize-javascript@^1.5.0:
+  version "1.5.0"
+  resolved "https://registry.yarnpkg.com/serialize-javascript/-/serialize-javascript-1.5.0.tgz#1aa336162c88a890ddad5384baebc93a655161fe"
+
 set-blocking@^2.0.0, set-blocking@~2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/set-blocking/-/set-blocking-2.0.0.tgz#045f9782d011ae9a6803ddd382b24392b3d890f7"