From faf44745f2023158275f3a2139e73f8e225b579d Mon Sep 17 00:00:00 2001
From: Zak Henry <zak@cloudnc.com>
Date: Sun, 18 Aug 2019 17:32:20 +0100
Subject: [PATCH] fix(Safari): Add default hardware concurrency value when one
 is not set

---
 package.json                                  |  2 +-
 .../src/lib/from-worker-pool.spec.ts          | 30 +++++++++++++++++++
 .../src/lib/from-worker-pool.ts               |  8 +++--
 3 files changed, 37 insertions(+), 3 deletions(-)

diff --git a/package.json b/package.json
index b984802..819130d 100644
--- a/package.json
+++ b/package.json
@@ -31,7 +31,7 @@
     "report-coverage": "codecov",
     "------------------ QUICK COMMANDS ------------------": "",
     "lint:fix": "yarn demo:lint:fix && yarn prettier:write",
-    "test": "yarn lib:test:watch",
+    "test": "yarn lib:test:watch --code-coverage",
     "start": "yarn demo:start",
     "commit": "git add . && git-cz"
   },
diff --git a/projects/observable-webworker/src/lib/from-worker-pool.spec.ts b/projects/observable-webworker/src/lib/from-worker-pool.spec.ts
index 9e6f169..5d6945c 100644
--- a/projects/observable-webworker/src/lib/from-worker-pool.spec.ts
+++ b/projects/observable-webworker/src/lib/from-worker-pool.spec.ts
@@ -205,6 +205,36 @@ describe('fromWorkerPool', () => {
     });
   });
 
+  describe('with undefined navigator.hardwareConcurrency', () => {
+    it('runs a default fallback number of workers', () => {
+      spyOnProperty(window.navigator, 'hardwareConcurrency').and.returnValue(undefined);
+
+      const input = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
+
+      const testWorkerStream$ = fromWorkerPool<number, number>(workerFactorySpy, input);
+      const subscriptionSpy = jasmine.createSpy('subscriptionSpy');
+      const sub = testWorkerStream$.subscribe(subscriptionSpy);
+
+      expect(workerFactorySpy).toHaveBeenCalledTimes(3);
+
+      sub.unsubscribe();
+    });
+
+    it('runs a configured fallback number of workers', () => {
+      spyOnProperty(window.navigator, 'hardwareConcurrency').and.returnValue(undefined);
+
+      const input = [0, 1, 2, 3, 4, 5, 6, 7, 8, 9];
+
+      const testWorkerStream$ = fromWorkerPool<number, number>(workerFactorySpy, input, { fallbackWorkerCount: 2 });
+      const subscriptionSpy = jasmine.createSpy('subscriptionSpy');
+      const sub = testWorkerStream$.subscribe(subscriptionSpy);
+
+      expect(workerFactorySpy).toHaveBeenCalledTimes(2);
+
+      sub.unsubscribe();
+    });
+  });
+
   describe('output strategy', () => {
     it('[default] outputs results as they are available', fakeAsync(() => {
       const workerCount = 7;
diff --git a/projects/observable-webworker/src/lib/from-worker-pool.ts b/projects/observable-webworker/src/lib/from-worker-pool.ts
index dc06cc6..2a58a72 100644
--- a/projects/observable-webworker/src/lib/from-worker-pool.ts
+++ b/projects/observable-webworker/src/lib/from-worker-pool.ts
@@ -12,6 +12,7 @@ interface LazyWorker {
 
 export interface WorkerPoolOptions<I, O> {
   workerCount?: number;
+  fallbackWorkerCount?: number;
   flattenOperator?: (input$: Observable<Observable<O>>) => Observable<O>;
   selectTransferables?: (input: I) => Transferable[];
 }
@@ -24,7 +25,8 @@ export function fromWorkerPool<I, O>(
   const {
     // tslint:disable-next-line:no-unnecessary-initializer
     selectTransferables = undefined,
-    workerCount = navigator.hardwareConcurrency - 1,
+    workerCount = navigator.hardwareConcurrency ? navigator.hardwareConcurrency - 1 : null,
+    fallbackWorkerCount = 3,
     flattenOperator = mergeAll<O>(),
   } = options || {};
 
@@ -35,7 +37,9 @@ export function fromWorkerPool<I, O>(
     let sent = 0;
     let finished = false;
 
-    const lazyWorkers: LazyWorker[] = Array.from({ length: workerCount }).map((_, index) => {
+    const lazyWorkers: LazyWorker[] = Array.from({
+      length: workerCount !== null ? workerCount : fallbackWorkerCount,
+    }).map((_, index) => {
       return {
         _cachedWorker: null,
         factory() {