Make concurrency change opt-in, but can only go lower

packages/artifact/__tests__/config.test.ts

@@ -1,4 +1,10 @@
 import * as config from '../src/internal/shared/config'
+import os from 'os'
+
+// Mock the 'os' module
+jest.mock('os', () => ({
+  cpus: jest.fn()
+}))
 
 beforeEach(() => {
   jest.resetModules()
@@ -35,10 +41,12 @@ describe('uploadChunkTimeoutEnv', () => {
   it('should return default 300000 when no env set', () => {
     expect(config.getUploadChunkTimeout()).toBe(300000)
   })
+
   it('should return value set in ACTIONS_UPLOAD_TIMEOUT_MS', () => {
     process.env.ACTIONS_UPLOAD_TIMEOUT_MS = '150000'
     expect(config.getUploadChunkTimeout()).toBe(150000)
   })
+
   it('should throw if value set in ACTIONS_UPLOAD_TIMEOUT_MS is invalid', () => {
     process.env.ACTIONS_UPLOAD_TIMEOUT_MS = 'abc'
     expect(() => {
@@ -46,3 +54,40 @@ describe('uploadChunkTimeoutEnv', () => {
     }).toThrow()
   })
 })
+
+describe('uploadConcurrencyEnv', () => {
+  it('should return default 32 when cpu num is <= 4', () => {
+    ;(os.cpus as jest.Mock).mockReturnValue(new Array(4))
+    expect(config.getConcurrency()).toBe(32)
+  })
+
+  it('should return 16 * num of cpu when cpu num is > 4', () => {
+    ;(os.cpus as jest.Mock).mockReturnValue(new Array(6))
+    expect(config.getConcurrency()).toBe(96)
+  })
+
+  it('should return up to 300 max value', () => {
+    ;(os.cpus as jest.Mock).mockReturnValue(new Array(32))
+    expect(config.getConcurrency()).toBe(300)
+  })
+
+  it('should return override value when ACTIONS_UPLOAD_CONCURRENCY is set', () => {
+    ;(os.cpus as jest.Mock).mockReturnValue(new Array(4))
+    process.env.ACTIONS_UPLOAD_CONCURRENCY = '10'
+    expect(config.getConcurrency()).toBe(10)
+  })
+
+  it('should throw with invalid value of ACTIONS_UPLOAD_CONCURRENCY', () => {
+    ;(os.cpus as jest.Mock).mockReturnValue(new Array(4))
+    process.env.ACTIONS_UPLOAD_CONCURRENCY = 'abc'
+    expect(() => {
+      config.getConcurrency()
+    }).toThrow()
+  })
+
+  it('cannot go over currency cap when override value is greater', () => {
+    ;(os.cpus as jest.Mock).mockReturnValue(new Array(4))
+    process.env.ACTIONS_UPLOAD_CONCURRENCY = '40'
+    expect(config.getConcurrency()).toBe(32)
+  })
+})