feat: support running suites in parallel

Author: hi-ogawa

examples/basic/test/repro.test.ts

@@ -0,0 +1,40 @@
+import { describe, test } from 'vitest'
+
+const sleep = (ms: number) => new Promise(resolve => setTimeout(resolve, ms))
+
+// finishes in 3 sec
+// (1st and 2nd suites in parallel)
+describe('example-1', () => {
+  // finishes in 3 sec
+  // (1st and 2nd cases in serial)
+  describe('1st suite', { concurrentSuite: true }, () => {
+    test('1st case', async () => {
+      await sleep(1000)
+    })
+    test('2nd case', async () => {
+      await sleep(2000)
+    })
+  })
+
+  describe('2nd suite', { concurrentSuite: true }, () => {
+    test('1st case', async () => {
+      await sleep(1000)
+    })
+    test('2nd case', async () => {
+      await sleep(2000)
+    })
+  })
+})
+
+// finishes in 3 sec
+// (same as example-1 but implemented as describe.each)
+describe('example-2', () => {
+  describe.each(['1st suite', '2nd suite'])('%s', { concurrentSuite: true }, () => {
+    test('1st case', async () => {
+      await sleep(1000)
+    })
+    test('2nd case', async () => {
+      await sleep(2000)
+    })
+  })
+})

packages/runner/src/suite.ts

@@ -172,7 +172,8 @@ function createSuiteCollector(name: string, factory: SuiteFactory = () => { }, m
     if (typeof suiteOptions === 'object')
       options = Object.assign({}, suiteOptions, options)
 
-    // inherit concurrent / sequential from suite
+    // TODO: `this.concurrent/sequential` always undefined?
+    // inherit concurrent / sequential from current suite
     options.concurrent = this.concurrent || (!this.sequential && options?.concurrent)
     options.sequential = this.sequential || (!this.concurrent && options?.sequential)
 
@@ -215,6 +216,7 @@ function createSuiteCollector(name: string, factory: SuiteFactory = () => { }, m
       tasks: [],
       meta: Object.create(null),
       projectName: '',
+      concurrent: suiteOptions?.concurrentSuite,
     }
 
     if (runner && includeLocation && runner.config.includeTaskLocation) {
@@ -282,7 +284,8 @@ function createSuite() {
     if (currentSuite?.options)
       options = { ...currentSuite.options, ...options }
 
-    // inherit concurrent / sequential from current suite
+    // TODO: `this.concurrent/sequential` always undefined?
+    // inherit test concurrent / sequential from current suite
     options.concurrent = this.concurrent || (!this.sequential && options?.concurrent)
     options.sequential = this.sequential || (!this.concurrent && options?.sequential)
 

packages/runner/src/types/tasks.ts

@@ -185,6 +185,10 @@ export interface TestOptions {
    * Tests inherit `concurrent` from `describe()` and nested `describe()` will inherit from parent's `concurrent`.
    */
   concurrent?: boolean
+  /**
+   * wip
+   */
+  concurrentSuite?: boolean
   /**
    * Whether tests run sequentially.
    * Tests inherit `sequential` from `describe()` and nested `describe()` will inherit from parent's `sequential`.