test: jest warning assert utils

packages/runtime-test/src/index.ts

@@ -10,4 +10,5 @@ export const render = createRenderer({
 export { serialize } from './serialize'
 export { triggerEvent } from './triggerEvent'
 export * from './nodeOps'
+export * from './jestUtils'
 export * from '@vue/runtime-core'

packages/runtime-test/src/jestUtils.ts

@@ -0,0 +1,83 @@
+declare global {
+  namespace jest {
+    interface Matchers<R> {
+      toHaveBeenWarned(): R
+      toHaveBeenWarnedLast(): R
+      toHaveBeenWarnedTimes(n: number): R
+    }
+  }
+}
+
+export function mockWarn() {
+  expect.extend({
+    toHaveBeenWarned(received: string) {
+      const passed = warn.mock.calls.some(
+        args => args[0].indexOf(received) > -1
+      )
+      if (passed) {
+        return {
+          pass: true,
+          message: () => `expected "${received}" not to have been warned.`
+        }
+      } else {
+        const msgs = warn.mock.calls.map(args => args[0]).join('\n - ')
+        return {
+          pass: false,
+          message: () =>
+            `expected "${received}" to have been warned.\n\nActual messages:\n\n - ${msgs}`
+        }
+      }
+    },
+
+    toHaveBeenWarnedLast(received: string) {
+      const passed =
+        warn.mock.calls[warn.mock.calls.length - 1][0].indexOf(received) > -1
+      if (passed) {
+        return {
+          pass: true,
+          message: () => `expected "${received}" not to have been warned last.`
+        }
+      } else {
+        const msgs = warn.mock.calls.map(args => args[0]).join('\n - ')
+        return {
+          pass: false,
+          message: () =>
+            `expected "${received}" to have been warned last.\n\nActual messages:\n\n - ${msgs}`
+        }
+      }
+    },
+
+    toHaveBeenWarnedTimes(received: string, n: number) {
+      let found = 0
+      warn.mock.calls.forEach(args => {
+        if (args[0].indexOf(received) > -1) {
+          found++
+        }
+      })
+      if (found > 0) {
+        return {
+          pass: true,
+          message: () =>
+            `expected "${received}" not to have been warned ${n} times.`
+        }
+      } else {
+        return {
+          pass: false,
+          message: () =>
+            `expected "${received}" to have been warned ${n} times but got ${found}.`
+        }
+      }
+    }
+  })
+
+  let warn: jest.SpyInstance
+
+  beforeEach(() => {
+    warn = jest.spyOn(console, 'warn')
+    warn.mockImplementation(() => {})
+  })
+
+  afterEach(() => {
+    warn.mockRestore()
+  })
+}