fix #155: reuse subprocess

src/main/mocha.ts

@@ -50,6 +50,7 @@ export default class MochaWrapper extends Mocha {
 
   setMaxParallel(maxParallel: number) {
     this.maxParallel = maxParallel;
+    return this;
   }
 
   enableExitMode() {

test/index.sh

@@ -76,6 +76,7 @@ test 'TESTCASE: --retries and --bail should work well together' test/bail-and-re
 test 'TESTCASE: subprocess exits before sending an end message' test/no-subprocess-end/index.js
 test 'TESTCASE: unhandled rejections should not force subprocess to exit' test/q-promises/index.js
 test 'TESTCASE: uncaught exceptions should not force subprocess to exit' test/uncaught-exception/index.js
+test 'TESTCASE: subprocess reusage' test/subprocess-reuse/index.js
 
 echo "Passes: $PASSES Failes: $FAILES"
 echo ""

test/subprocess-reuse/.gitignore

@@ -0,0 +1 @@
+counter.json

test/subprocess-reuse/README

@@ -0,0 +1 @@
+Check that subprocesses are reused

test/subprocess-reuse/index.js

@@ -0,0 +1,32 @@
+#!/usr/bin/env node
+
+const assert = require('assert');
+const { writeFileSync } = require('fs');
+const { resolve } = require('path');
+const MochaParallelTests = require('../../dist/main/mocha').default;
+
+const counterFilePath = resolve(__dirname, 'counter.json');
+const reporterPath = resolve(__dirname, '../util/silent-reporter.js');
+
+process.on('unhandledRejection', (reason) => {
+    console.error(reason.stack);
+    process.exit(1);
+});
+
+// initialize counter file
+writeFileSync(counterFilePath, '[]');
+
+const mocha = new MochaParallelTests();
+mocha
+    .reporter(reporterPath)
+    .addFile(`${__dirname}/spec/1.spec.js`)
+    .addFile(`${__dirname}/spec/2.spec.js`)
+    .addFile(`${__dirname}/spec/3.spec.js`)
+    .addFile(`${__dirname}/spec/4.spec.js`)
+    .slow(5000)
+    .setMaxParallel(2)
+    .run()
+    .on('end', function () {
+        const pidsUsed = require(counterFilePath);
+        assert.strictEqual(pidsUsed.length, 2, `Number of processes is wrong: ${pidsUsed.length}`);
+    });

test/subprocess-reuse/spec/1.spec.js

@@ -0,0 +1,17 @@
+const { writeFileSync } = require('fs');
+const { resolve } = require('path');
+
+const updateCounterWithOwnPid = () => {
+    const counterFilePath = resolve(__dirname, '../counter.json');
+    const pids = new Set(require(counterFilePath));
+
+    pids.add(process.pid);
+    writeFileSync(counterFilePath, JSON.stringify([...pids]));
+};
+
+describe('suite', () => {
+    it('case', (done) => {
+        updateCounterWithOwnPid();
+        setTimeout(done, 1000);
+    });
+});

test/subprocess-reuse/spec/2.spec.js

@@ -0,0 +1,17 @@
+const { writeFileSync } = require('fs');
+const { resolve } = require('path');
+
+const updateCounterWithOwnPid = () => {
+    const counterFilePath = resolve(__dirname, '../counter.json');
+    const pids = new Set(require(counterFilePath));
+
+    pids.add(process.pid);
+    writeFileSync(counterFilePath, JSON.stringify([...pids]));
+};
+
+describe('suite', () => {
+    it('case', (done) => {
+        updateCounterWithOwnPid();
+        setTimeout(done, 1000);
+    });
+});

test/subprocess-reuse/spec/3.spec.js

@@ -0,0 +1,17 @@
+const { writeFileSync } = require('fs');
+const { resolve } = require('path');
+
+const updateCounterWithOwnPid = () => {
+    const counterFilePath = resolve(__dirname, '../counter.json');
+    const pids = new Set(require(counterFilePath));
+
+    pids.add(process.pid);
+    writeFileSync(counterFilePath, JSON.stringify([...pids]));
+};
+
+describe('suite', () => {
+    it('case', (done) => {
+        updateCounterWithOwnPid();
+        setTimeout(done, 1000);
+    });
+});

test/subprocess-reuse/spec/4.spec.js

@@ -0,0 +1,17 @@
+const { writeFileSync } = require('fs');
+const { resolve } = require('path');
+
+const updateCounterWithOwnPid = () => {
+    const counterFilePath = resolve(__dirname, '../counter.json');
+    const pids = new Set(require(counterFilePath));
+
+    pids.add(process.pid);
+    writeFileSync(counterFilePath, JSON.stringify([...pids]));
+};
+
+describe('suite', () => {
+    it('case', (done) => {
+        updateCounterWithOwnPid();
+        setTimeout(done, 1000);
+    });
+});