fix: support for NodeJS 15, fixes #732

src/util/performance.spec.ts

@@ -0,0 +1,28 @@
+import { getPerformance } from './performance'
+
+describe('performance', () => {
+  let globalPerformance: Performance
+  beforeEach(() => {
+    globalPerformance = global.performance
+  })
+  afterEach(() => {
+    global.performance = globalPerformance
+    delete (global as any).window
+  })
+  it('should use global.performance if exist', () => {
+    const performance = {} as any as Performance
+    global.performance = performance
+    expect(getPerformance()).toEqual(performance)
+  })
+  it('should use window.performance if exist', () => {
+    const performance = {} as any as Performance
+    delete (global as any).performance
+    global.window = { performance } as any
+    expect(getPerformance()).toEqual(performance)
+  })
+  it('should use polyfill if no window/global.performance', () => {
+    delete (global as any).performance
+    const now = getPerformance().now()
+    expect(Number.isInteger(now)).toBeTruthy()
+  })
+})

src/util/performance.ts

@@ -0,0 +1,13 @@
+interface LiquidPerformance {
+  now: () => number
+}
+
+const polyfill: LiquidPerformance = {
+  now: () => Date.now()
+}
+
+export function getPerformance (): LiquidPerformance {
+  return (typeof global === 'object' && global.performance) ||
+    (typeof window === 'object' && window.performance) ||
+    polyfill
+}