snapshot of https://github.com/tauri-apps/tauri.git (dev, 2026-09-23; blobs > 131072B omitted)

packages/api-e2e/test/specs/event.spec.ts

@@ -0,0 +1,125 @@
+// Copyright 2019-2024 Tauri Programme within The Commons Conservancy
+// SPDX-License-Identifier: Apache-2.0
+// SPDX-License-Identifier: MIT
+
+import { expect } from '@wdio/globals'
+import { tauri, describeApi } from '../helpers/index.js'
+
+describeApi('event', () => {
+  it('listen receives an emitted payload', async () => {
+    const payload = await tauri(
+      (api) =>
+        new Promise<{ hello: string }>((resolve, reject) => {
+          api.event
+            .listen<{ hello: string }>('e2e://ping', (event) =>
+              resolve(event.payload)
+            )
+            .then((unlisten) => {
+              api.event.emit('e2e://ping', { hello: 'world' }).catch(reject)
+              setTimeout(() => {
+                unlisten()
+                reject(new Error('event was not received'))
+              }, 5000)
+            })
+            .catch(reject)
+        })
+    )
+    expect(payload).toEqual({ hello: 'world' })
+  })
+
+  it('once fires exactly once even if the event is emitted twice', async () => {
+    const count = await tauri(
+      (api) =>
+        new Promise<number>((resolve, reject) => {
+          let calls = 0
+          api.event
+            .once('e2e://once', () => {
+              calls++
+            })
+            .then(async () => {
+              await api.event.emit('e2e://once')
+              await api.event.emit('e2e://once')
+              setTimeout(() => resolve(calls), 1000)
+            })
+            .catch(reject)
+        })
+    )
+    expect(count).toBe(1)
+  })
+
+  it('unlisten stops further delivery', async () => {
+    const count = await tauri(
+      (api) =>
+        new Promise<number>((resolve, reject) => {
+          let calls = 0
+          api.event
+            .listen('e2e://off', () => {
+              calls++
+            })
+            .then(async (unlisten) => {
+              await api.event.emit('e2e://off')
+              setTimeout(async () => {
+                await unlisten()
+                await api.event.emit('e2e://off')
+                setTimeout(() => resolve(calls), 500)
+              }, 500)
+            })
+            .catch(reject)
+        })
+    )
+    expect(count).toBe(1)
+  })
+
+  it('emitTo delivers only to the targeted label', async () => {
+    const result = await tauri(
+      (api) =>
+        new Promise<{ mainCount: number }>((resolve, reject) => {
+          let mainCount = 0
+          api.event
+            // The listener must be scoped to the `main` label: a default
+            // `listen()` registers the `Any` target, a catch-all that receives
+            // every emit regardless of the `emitTo` label (so it would also see
+            // the `does-not-exist` emit).
+            .listen(
+              'e2e://target',
+              () => {
+                mainCount++
+              },
+              { target: 'main' }
+            )
+            .then(async (unlisten) => {
+              await api.event.emitTo('main', 'e2e://target') // delivered
+              await api.event.emitTo('does-not-exist', 'e2e://target') // dropped
+              setTimeout(async () => {
+                await unlisten()
+                resolve({ mainCount })
+              }, 800)
+            })
+            .catch(reject)
+        })
+    )
+    expect(result.mainCount).toBe(1)
+  })
+
+  it('bridges events to and from the Rust backend', async () => {
+    // examples/api listens for `js-event` and replies with `rust-event { data }`.
+    const reply = await tauri(
+      (api) =>
+        new Promise<{ data: string }>((resolve, reject) => {
+          api.event
+            .listen<{ data: string }>('rust-event', (event) =>
+              resolve(event.payload)
+            )
+            .then((unlisten) => {
+              api.event.emit('js-event', 'hello from e2e').catch(reject)
+              setTimeout(() => {
+                unlisten()
+                reject(new Error('no rust-event reply received'))
+              }, 5000)
+            })
+            .catch(reject)
+        })
+    )
+    expect(reply).toEqual({ data: 'something else' })
+  })
+})