From 764ee19029f1abc0458a70f9587c70dcd806b0c0 Mon Sep 17 00:00:00 2001
From: Patrik Oldsberg <poldsberg@gmail.com>
Date: Mon, 7 Feb 2022 17:42:32 +0100
Subject: [PATCH] cli: switch to looping parallel workers + fix bump test log
 ordering

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>
---
 .../cli/src/commands/versions/bump.test.ts    | 22 ++++++++---------
 packages/cli/src/lib/parallel.ts              | 24 +++++++++----------
 2 files changed, 22 insertions(+), 24 deletions(-)

diff --git a/packages/cli/src/commands/versions/bump.test.ts b/packages/cli/src/commands/versions/bump.test.ts
index 2dadd06d1d..ae1a4c4627 100644
--- a/packages/cli/src/commands/versions/bump.test.ts
+++ b/packages/cli/src/commands/versions/bump.test.ts
@@ -127,8 +127,8 @@ describe('bump', () => {
     });
     expect(logs.filter(Boolean)).toEqual([
       'Using default pattern glob @backstage/*',
-      'Checking for updates of @backstage/theme',
       'Checking for updates of @backstage/core',
+      'Checking for updates of @backstage/theme',
       'Checking for updates of @backstage/core-api',
       'Some packages are outdated, updating',
       'unlocking @backstage/core@^1.0.3 ~> 1.0.6',
@@ -252,19 +252,19 @@ describe('bump', () => {
     });
     expect(logs.filter(Boolean)).toEqual([
       'Using custom pattern glob @{backstage,backstage-extra}/*',
-      'Checking for updates of @backstage/theme',
-      'Checking for updates of @backstage-extra/custom-two',
-      'Checking for updates of @backstage-extra/custom',
       'Checking for updates of @backstage/core',
+      'Checking for updates of @backstage-extra/custom',
+      'Checking for updates of @backstage-extra/custom-two',
+      'Checking for updates of @backstage/theme',
       'Checking for updates of @backstage/core-api',
       'Some packages are outdated, updating',
-      'unlocking @backstage-extra/custom@^1.0.1 ~> 1.1.0',
       'unlocking @backstage/core@^1.0.3 ~> 1.0.6',
+      'unlocking @backstage-extra/custom@^1.0.1 ~> 1.1.0',
       'unlocking @backstage/core-api@^1.0.6 ~> 1.0.7',
       'unlocking @backstage/core-api@^1.0.3 ~> 1.0.7',
       'bumping @backstage-extra/custom-two in a to ^2.0.0',
-      'bumping @backstage/theme in b to ^2.0.0',
       'bumping @backstage-extra/custom-two in b to ^2.0.0',
+      'bumping @backstage/theme in b to ^2.0.0',
       'Running yarn install to install new versions',
       '⚠️  The following packages may have breaking changes:',
       '  @backstage-extra/custom-two : 1.0.0 ~> 2.0.0',
@@ -348,14 +348,14 @@ describe('bump', () => {
     });
     expect(logs.filter(Boolean)).toEqual([
       'Using default pattern glob @backstage/*',
-      'Checking for updates of @backstage/theme',
       'Checking for updates of @backstage/core',
-      'Package info not found, ignoring package @backstage/theme',
-      'Package info not found, ignoring package @backstage/core',
       'Checking for updates of @backstage/theme',
-      'Checking for updates of @backstage/core',
-      'Package info not found, ignoring package @backstage/theme',
       'Package info not found, ignoring package @backstage/core',
+      'Package info not found, ignoring package @backstage/theme',
+      'Checking for updates of @backstage/core',
+      'Checking for updates of @backstage/theme',
+      'Package info not found, ignoring package @backstage/core',
+      'Package info not found, ignoring package @backstage/theme',
       'All Backstage packages are up to date!',
     ]);
 
diff --git a/packages/cli/src/lib/parallel.ts b/packages/cli/src/lib/parallel.ts
index e1a56770fd..f8af967d22 100644
--- a/packages/cli/src/lib/parallel.ts
+++ b/packages/cli/src/lib/parallel.ts
@@ -72,21 +72,19 @@ export async function runParallelWorkers<TItem>(
     ? parseParallelismOption(parallelismSetting)
     : getEnvironmentParallelism();
 
-  const iterator = items[Symbol.iterator]();
-
-  async function pop() {
-    const el = iterator.next();
-    if (el.done) {
-      return;
-    }
-
-    await worker(el.value);
-    await pop();
-  }
+  const sharedIterator = items[Symbol.iterator]();
+  const sharedIterable = {
+    [Symbol.iterator]: () => sharedIterator,
+  };
 
+  const workerCount = Math.max(Math.floor(parallelismFactor * parallelism), 1);
   return Promise.all(
-    Array(Math.max(Math.floor(parallelismFactor * parallelism), 1))
+    Array(workerCount)
       .fill(0)
-      .map(() => pop()),
+      .map(async () => {
+        for (const value of sharedIterable) {
+          await worker(value);
+        }
+      }),
   );
 }