From 8e13010fe0547827f2e99c5c55a77aa63f5fe22d Mon Sep 17 00:00:00 2001
From: Vitalii Parovishnyk <870237+ikorich@users.noreply.github.com>
Date: Thu, 11 Jun 2026 23:54:23 +0300
Subject: [PATCH] #24 fix(example): bind this when calling Response.json()

The #8 rewrite extracted `responseObject.json.function` and invoked it
unbound, so `this` was undefined and every fetch tick failed in real
browsers with "Illegal invocation". Call it bound via `jsonFn(this:)`.

Verified end-to-end in Chrome and in iOS Simulator Safari via the
PackageToJS `--use-cdn` browser bundle; README gains a "Running the
example" guide (bundle, index.html loader, static serve, simulator
Safari) so the run path is documented.

Fixes #24
---
 CHANGELOG.md                            | 14 +++++++++
 README.md                               | 41 ++++++++++++++++++++++++-
 Sources/OpenCombineJSExample/main.swift |  4 ++-
 3 files changed, 57 insertions(+), 2 deletions(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 57157d2..f2e220e 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,3 +1,17 @@
+# 0.6.1 (2026-06-11)
+
+**Fixed:**
+
+- Example: `Response.json()` was invoked without its `this` binding, failing every fetch
+  tick in a real browser with "Illegal invocation"; it is now called bound via
+  `jsonFn(this:)` ([#24](https://github.com/IGRSoft/OpenCombineJS/issues/24))
+
+**Documentation:**
+
+- README gains a "Running the example" guide: PackageToJS `--use-cdn` bundling, the
+  `index.html` loader, static serving, and opening the example in a host browser or the
+  iOS Simulator's Safari ([#24](https://github.com/IGRSoft/OpenCombineJS/issues/24))
+
 # 0.6.0 (2026-06-11)
 
 **Build/packaging change — no public API is removed or deprecated:**
diff --git a/README.md b/README.md
index 7d17b1a..d59bc7c 100644
--- a/README.md
+++ b/README.md
@@ -60,7 +60,8 @@ let timer = JSTimer(millisecondsDelay: 1000, isRepeating: true) {
       guard
         let obj = responseValue.object,
         let jsonFn = obj.json.function,
-        let jsonObj = jsonFn().object,
+        // `Response.json` must be called with the response as `this`.
+        let jsonObj = jsonFn(this: obj).object,
         let jsonPromise = JSPromise(jsonObj)
       else {
         return JSPromise(resolver: { resolve in
@@ -95,6 +96,44 @@ let timer = JSTimer(millisecondsDelay: 1000, isRepeating: true) {
 }
 ```
 
+## Running the example
+
+The example is a WebAssembly program: it needs a browser. It cannot run as a native
+process on macOS or an iOS simulator — JavaScriptKit's native builds exist only for
+editor/type-checking support (the JS bridge is compiled `#if __wasm32__`), so a native
+launch aborts immediately.
+
+1. Bundle for the browser (requires the official wasm Swift SDK matching your toolchain,
+   e.g. `swift-6.3.2-RELEASE_wasm`):
+
+   ```console
+   swift package --disable-sandbox --swift-sdk swift-6.3.2-RELEASE_wasm \
+     js --use-cdn --product OpenCombineJSExample
+   ```
+
+2. Put an `index.html` next to the produced bundle
+   (`.build/plugins/PackageToJS/outputs/Package/`):
+
+   ```html
+   <script type="module">
+     import { init } from "./index.js";
+     await init();
+   </script>
+   ```
+
+3. Serve the bundle directory and open it — any browser works, including Safari inside
+   a booted iOS simulator:
+
+   ```console
+   python3 -m http.server 8741 --directory .build/plugins/PackageToJS/outputs/Package
+   open http://127.0.0.1:8741/index.html                          # host browser
+   xcrun simctl openurl booted http://127.0.0.1:8741/index.html   # iOS Simulator Safari
+   ```
+
+`--use-cdn` resolves the WASI shim dependency from a CDN; without it, browsers cannot
+resolve the bundle's bare `@bjorn3/browser_wasi_shim` import unless you `npm install`
+in the output directory and serve through a bundler.
+
 ### Code of Conduct
 
 This project adheres to the [Contributor Covenant Code of
diff --git a/Sources/OpenCombineJSExample/main.swift b/Sources/OpenCombineJSExample/main.swift
index 7c0a75f..8b5fcf6 100644
--- a/Sources/OpenCombineJSExample/main.swift
+++ b/Sources/OpenCombineJSExample/main.swift
@@ -84,7 +84,9 @@ let timer = JSTimer(millisecondsDelay: 1000, isRepeating: true) {
       guard
         let responseObject = responseValue.object,
         let jsonFn = responseObject.json.function,
-        let jsonPromiseObject = jsonFn().object,
+        // `Response.json` must be called WITH the response as `this` — an unbound
+        // call throws "Illegal invocation" in browsers (#24).
+        let jsonPromiseObject = jsonFn(this: responseObject).object,
         let jsonPromise = JSPromise(jsonPromiseObject)
       else {
         // Return a publisher that immediately fails if the response is malformed.