From 85826ddafef4fb8d4e9e8dc5a76e4b79ba9d884f Mon Sep 17 00:00:00 2001
From: FabianLars <fabianlars@fabianlars.de>
Date: Wed, 3 Jan 2024 17:11:36 +0100
Subject: [PATCH 1/2] fix(api.js): mock `__TAURI_INTERNALS__` in `mockIPC` and
 `mockWindows`

---
 .changes/fix-mock-tauri-internals.md | 5 +++++
 tooling/api/src/mocks.ts             | 8 +++++++-
 2 files changed, 12 insertions(+), 1 deletion(-)
 create mode 100644 .changes/fix-mock-tauri-internals.md

diff --git a/.changes/fix-mock-tauri-internals.md b/.changes/fix-mock-tauri-internals.md
new file mode 100644
index 000000000000..25a7b2ebb74a
--- /dev/null
+++ b/.changes/fix-mock-tauri-internals.md
@@ -0,0 +1,5 @@
+---
+'@tauri-apps/api': 'patch:bug'
+---
+
+`mockIPC` and `mockWindows` no longer crash if `window.__TAURI_INTERNALS__` is undefined.
diff --git a/tooling/api/src/mocks.ts b/tooling/api/src/mocks.ts
index f7fcd880510e..edaf50efd2fd 100644
--- a/tooling/api/src/mocks.ts
+++ b/tooling/api/src/mocks.ts
@@ -9,6 +9,10 @@ interface IPCMessage {
   [key: string]: unknown
 }
 
+function mockInternals() {
+  window.__TAURI_INTERNALS__ = window.__TAURI_INTERNALS__ ?? {}
+}
+
 /**
  * Intercepts all IPC requests with the given mock handler.
  *
@@ -65,6 +69,7 @@ interface IPCMessage {
 export function mockIPC(
   cb: (cmd: string, payload: Record<string, unknown>) => unknown
 ): void {
+  mockInternals()
   // eslint-disable-next-line @typescript-eslint/no-misused-promises
   window.__TAURI_INTERNALS__.ipc = async ({
     cmd,
@@ -128,6 +133,7 @@ export function mockWindows(
   current: string,
   ...additionalWindows: string[]
 ): void {
+  mockInternals()
   window.__TAURI_INTERNALS__.metadata = {
     windows: [current, ...additionalWindows].map((label) => ({ label })),
     currentWindow: { label: current }
@@ -153,7 +159,7 @@ export function mockWindows(
  * @since 1.6.0
  */
 export function mockConvertFileSrc(osName: string): void {
-  window.__TAURI_INTERNALS__ = window.__TAURI_INTERNALS__ ?? {}
+  mockInternals()
   window.__TAURI_INTERNALS__.convertFileSrc = function (
     filePath,
     protocol = 'asset'

From 4a79fd38706d065e18203608ef34de067fb5c8d6 Mon Sep 17 00:00:00 2001
From: FabianLars <fabianlars@fabianlars.de>
Date: Wed, 3 Jan 2024 20:05:29 +0100
Subject: [PATCH 2/2] mock internals.invoke instead of internals.ipc

---
 tooling/api/src/mocks.ts | 61 ++++++++++++++++++++++++----------------
 1 file changed, 36 insertions(+), 25 deletions(-)

diff --git a/tooling/api/src/mocks.ts b/tooling/api/src/mocks.ts
index edaf50efd2fd..e6022d39546f 100644
--- a/tooling/api/src/mocks.ts
+++ b/tooling/api/src/mocks.ts
@@ -2,12 +2,7 @@
 // SPDX-License-Identifier: Apache-2.0
 // SPDX-License-Identifier: MIT
 
-interface IPCMessage {
-  cmd: string
-  callback: number
-  error: number
-  [key: string]: unknown
-}
+import { InvokeArgs, InvokeOptions } from './core'
 
 function mockInternals() {
   window.__TAURI_INTERNALS__ = window.__TAURI_INTERNALS__ ?? {}
@@ -67,25 +62,41 @@ function mockInternals() {
  * @since 1.0.0
  */
 export function mockIPC(
-  cb: (cmd: string, payload: Record<string, unknown>) => unknown
+  cb: <T>(cmd: string, payload?: InvokeArgs) => Promise<T>
 ): void {
   mockInternals()
-  // eslint-disable-next-line @typescript-eslint/no-misused-promises
-  window.__TAURI_INTERNALS__.ipc = async ({
-    cmd,
-    callback,
-    error,
-    payload
-  }: IPCMessage) => {
-    try {
-      // @ts-expect-error The function key is dynamic and therefore not typed
-      // eslint-disable-next-line @typescript-eslint/no-unsafe-call
-      window[`_${callback}`](await cb(cmd, payload))
-    } catch (err) {
-      // @ts-expect-error The function key is dynamic and therefore not typed
-      // eslint-disable-next-line @typescript-eslint/no-unsafe-call
-      window[`_${error}`](err)
-    }
+
+  window.__TAURI_INTERNALS__.transformCallback = function transformCallback(
+    // eslint-disable-next-line @typescript-eslint/no-explicit-any
+    callback?: (response: any) => void,
+    once = false
+  ) {
+    const identifier = window.crypto.getRandomValues(new Uint32Array(1))[0]
+    const prop = `_${identifier}`
+
+    Object.defineProperty(window, prop, {
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      value: (result: any) => {
+        if (once) {
+          Reflect.deleteProperty(window, prop)
+        }
+
+        return callback && callback(result)
+      },
+      writable: false,
+      configurable: true
+    })
+
+    return identifier
+  }
+
+  window.__TAURI_INTERNALS__.invoke = function <T>(
+    cmd: string,
+    args?: InvokeArgs,
+    // eslint-disable-next-line @typescript-eslint/no-unused-vars
+    options?: InvokeOptions
+  ): Promise<T> {
+    return cb(cmd, args)
   }
 }
 
@@ -205,9 +216,9 @@ export function clearMocks(): void {
   if (window.__TAURI_INTERNALS__?.convertFileSrc)
     // @ts-expect-error "The operand of a 'delete' operator must be optional' does not matter in this case
     delete window.__TAURI_INTERNALS__.convertFileSrc
-  if (window.__TAURI_INTERNALS__?.ipc)
+  if (window.__TAURI_INTERNALS__?.invoke)
     // @ts-expect-error "The operand of a 'delete' operator must be optional' does not matter in this case
-    delete window.__TAURI_INTERNALS__.ipc
+    delete window.__TAURI_INTERNALS__.invoke
   if (window.__TAURI_INTERNALS__?.metadata)
     // @ts-expect-error "The operand of a 'delete' operator must be optional' does not matter in this case
     delete window.__TAURI_INTERNALS__.metadata