Reuse an already-booted iOS simulator instead of hanging

IOSEmulatorManager.getTargetEmulator always picked the most recent
iPhone simulator from `simctl list`, regardless of whether a
different simulator was already booted. When one was, the boot-ready
check kept failing and the manager tried to boot a second simulator,
which conflicted with the first and hung until the retry loop timed
out.

Now, unless IOS_EMU pins a specific simulator, the picker reuses
whichever simulator is already booted. Rewritten with async/await,
matching the style already used elsewhere in this file.

Author: ofalvai

CLAUDE.md

@@ -56,7 +56,6 @@ React Native CodePush is a native module that enables over-the-air updates for R
   - For the fast local loop: run `test:setup:ios` once per template/dependency change, then re-run `test:fast:ios` repeatedly while iterating on test/scenario code — this skips `pod install` and re-provisioning on every iteration.
   - There's still no "just build, no tests" npm script — for a raw build only, lift the `xcodebuild` invocation out of `RNIOS.buildApp` in `test/test.ts` and run it by hand against the provisioned `TestCodePush.xcworkspace`.
 - When debugging a CI failure, don't trust the first plausible-looking theory from log noise — reproduce the exact failing command locally on matching hardware/toolchain before writing up a root cause. This is faster than iterating against multi-hour CI runs and catches wrong hypotheses early.
-- Before running `npm run test:setup:ios`, shut down all booted simulators (`xcrun simctl shutdown all`) — the test framework's simulator picker hangs silently (no error) if simulators are already booted outside it.
 - `npm run test:setup:ios` provisions a full test app outside the repo (under a system temp/`test-run` dir), not inside `test/` — expect to search for it rather than finding it checked into the repo tree.
 - The provisioned test app's `node_modules/@bitrise/code-push-sdk` is a real copy, not a symlink — editing `ios/` (or `android/`) native source in the repo has zero effect on `test:fast:ios` runs until you re-copy those files into that `node_modules` path (or rerun `test:setup:ios`).
 

code-push-plugin-testing-framework/script/platform.js

@@ -347,36 +347,27 @@ var IOSEmulatorManager = (function () {
     /**
      * Returns the target emulator, which is specified through the command line.
      */
-    IOSEmulatorManager.prototype.getTargetEmulator = function () {
-        let _this = this;
-        if (this.targetEmulator)
-            return Q(this.targetEmulator);
-        else {
-            let deferred = Q.defer();
-            let targetIOSEmulator = process.env.IOS_EMU;
-            if (!targetIOSEmulator) {
-                // If no iOS simulator is specified, get the most recent iOS simulator to run tests on.
-                testUtil_1.TestUtil.getProcessOutput("xcrun simctl list", { noLogCommand: true, noLogStdOut: true, noLogStdErr: true })
-                    .then((listOfDevicesWithDevicePairs) => {
-                        let listOfDevices = listOfDevicesWithDevicePairs.slice(listOfDevicesWithDevicePairs.indexOf("-- iOS"), listOfDevicesWithDevicePairs.indexOf("-- tvOS"));
-                        let phoneDevice = /iPhone\ \S*\ ?.*?\(([0-9A-Z-]*)\)/g;
-                        let match = phoneDevice.exec(listOfDevices);
-                        deferred.resolve(match[1]);
-                    }, (error) => {
-                        deferred.reject(error);
-                    });
-            }
-            else {
-                // Use the simulator specified on the command line.
-                deferred.resolve(targetIOSEmulator);
+    IOSEmulatorManager.prototype.getTargetEmulator = async function () {
+        if (this.targetEmulator) {
+            return this.targetEmulator;
+        }
+        let targetEmulator = process.env.IOS_EMU;
+        if (!targetEmulator) {
+            try {
+                const bootedUdid = await testUtil_1.TestUtil.getProcessOutput("xcrun simctl getenv booted SIMULATOR_UDID", { noLogCommand: true, noLogStdOut: true, noLogStdErr: true });
+                targetEmulator = bootedUdid.trim();
+            } catch {
+                // No simulator is currently booted - fall back to the most recent iOS simulator.
+                const listOfDevicesWithDevicePairs = await testUtil_1.TestUtil.getProcessOutput("xcrun simctl list", { noLogCommand: true, noLogStdOut: true, noLogStdErr: true });
+                const listOfDevices = listOfDevicesWithDevicePairs.slice(listOfDevicesWithDevicePairs.indexOf("-- iOS"), listOfDevicesWithDevicePairs.indexOf("-- tvOS"));
+                const phoneDevice = /iPhone\ \S*\ ?.*?\(([0-9A-Z-]*)\)/g;
+                const match = phoneDevice.exec(listOfDevices);
+                targetEmulator = match[1];
             }
-            return deferred.promise
-                .then((targetEmulator) => {
-                    _this.targetEmulator = targetEmulator;
-                    console.log("Using iOS simulator named " + _this.targetEmulator);
-                    return _this.targetEmulator;
-                });
         }
+        this.targetEmulator = targetEmulator;
+        console.log("Using iOS simulator named " + this.targetEmulator);
+        return this.targetEmulator;
     };
     /**
      * Boots the target emulator.