From 73fc0a897904a6b19e45abb45ce0a14a79f7ddd6 Mon Sep 17 00:00:00 2001
From: Nico Jansen <jansennico@gmail.com>
Date: Fri, 26 Apr 2019 18:04:19 +0200
Subject: [PATCH] fix(clean up): prevent sandbox creation after dispose (#1527)

---
 packages/core/src/SandboxPool.ts            | 16 +++++++++---
 packages/core/test/unit/SandboxPool.spec.ts | 28 +++++++++++++++++++++
 2 files changed, 40 insertions(+), 4 deletions(-)

diff --git a/packages/core/src/SandboxPool.ts b/packages/core/src/SandboxPool.ts
index fa1877e8cd..498cdef801 100644
--- a/packages/core/src/SandboxPool.ts
+++ b/packages/core/src/SandboxPool.ts
@@ -1,6 +1,6 @@
 import * as os from 'os';
 import { range, Subject, Observable } from 'rxjs';
-import { flatMap, tap, zip, merge, map } from 'rxjs/operators';
+import { flatMap, tap, zip, merge, map, filter } from 'rxjs/operators';
 import { File, StrykerOptions } from '@stryker-mutator/api/core';
 import { TestFramework } from '@stryker-mutator/api/test_framework';
 import Sandbox from './Sandbox';
@@ -60,9 +60,15 @@ export class SandboxPool implements Disposable {
     const concurrency = this.determineConcurrency();
 
     return range(0, concurrency).pipe(
-      flatMap(n => {
-        return this.registerSandbox(Sandbox.create(this.options, n, this.initialFiles, this.testFramework, this.overheadTimeMS, this.loggingContext));
-      }, MAX_CONCURRENT_INITIALIZING_SANDBOXES)
+      flatMap(async n => {
+        if (this.isDisposed) {
+          return null;
+        } else {
+          return this.registerSandbox(Sandbox.create(this.options, n, this.initialFiles, this.testFramework, this.overheadTimeMS, this.loggingContext));
+        }
+      }, MAX_CONCURRENT_INITIALIZING_SANDBOXES),
+      filter(sandboxOrNull => !!sandboxOrNull),
+      map(sandbox => sandbox as Sandbox)
     );
   }
 
@@ -89,7 +95,9 @@ export class SandboxPool implements Disposable {
     return promisedSandbox;
   }
 
+  private isDisposed = false;
   public async dispose() {
+    this.isDisposed = true;
     const sandboxes = await Promise.all(this.allSandboxes);
     return Promise.all(sandboxes.map(sandbox => sandbox.dispose()));
   }
diff --git a/packages/core/test/unit/SandboxPool.spec.ts b/packages/core/test/unit/SandboxPool.spec.ts
index ca75355da4..65c30b84f7 100644
--- a/packages/core/test/unit/SandboxPool.spec.ts
+++ b/packages/core/test/unit/SandboxPool.spec.ts
@@ -178,6 +178,7 @@ describe(SandboxPool.name, () => {
       await expect(actRunMutants()).rejectedWith(expectedError);
     });
   });
+
   describe('dispose', () => {
     it('should have disposed all sandboxes', async () => {
       sut = createSut();
@@ -216,5 +217,32 @@ describe(SandboxPool.name, () => {
       await disposePromise;
       expect(secondSandbox.dispose).called;
     });
+
+    it('should halt creating of new sandboxes', async () => {
+      // Arrange
+      sut = createSut();
+      sinon.stub(os, 'cpus').returns([1, 2, 3]); // stub 3 cpus
+      const task = new Task<Sandbox>();
+      const task2 = new Task<Sandbox>();
+      createStub.reset();
+      createStub
+        .onCall(0).returns(task.promise)
+        .onCall(1).returns(task2.promise)
+        .onCall(2).resolves(genericSandboxForAllSubsequentCallsToNewSandbox); // promise is not yet resolved
+      inputMutants.push(transpiledMutant(), transpiledMutant()); // 3 mutants
+
+      // Act
+      const runPromise = sut.runMutants(from(inputMutants))
+        .pipe(toArray())
+        .toPromise();
+      const disposePromise = sut.dispose();
+      task.resolve(firstSandbox as unknown as Sandbox);
+      task2.resolve(secondSandbox as unknown as Sandbox);
+      await disposePromise;
+      await runPromise;
+
+      // Assert
+      expect(createStub).calledTwice;
+    });
   });
 });