fix: ignore exception thrown when `AppRegistry` is missing (#763)

common/AppRegistry.cpp

@@ -17,33 +17,40 @@ std::vector<std::string> ReactTestApp::GetAppKeys(Runtime &runtime)
         return result;
     }
 
-    // const appRegistry = __fbBatchedBridge.getCallableModule("AppRegistry");
-    auto fbBatchedBridge = global.getPropertyAsObject(runtime, kFbBatchedBridgeId);
-    auto getCallableModule = fbBatchedBridge.getPropertyAsFunction(runtime, "getCallableModule");
-    auto appRegistry =
-        getCallableModule.callWithThis(runtime, fbBatchedBridge, "AppRegistry").asObject(runtime);
+    try {
+        // const appRegistry = __fbBatchedBridge.getCallableModule("AppRegistry");
+        auto fbBatchedBridge = global.getPropertyAsObject(runtime, kFbBatchedBridgeId);
+        auto getCallableModule =
+            fbBatchedBridge.getPropertyAsFunction(runtime, "getCallableModule");
+        auto appRegistry = getCallableModule.callWithThis(runtime, fbBatchedBridge, "AppRegistry")
+                               .asObject(runtime);
 
-    // const appKeys = appRegistry.getAppKeys();
-    auto getAppKeys = appRegistry.getPropertyAsFunction(runtime, "getAppKeys");
-    auto appKeys = getAppKeys.callWithThis(runtime, appRegistry).asObject(runtime).asArray(runtime);
+        // const appKeys = appRegistry.getAppKeys();
+        auto getAppKeys = appRegistry.getPropertyAsFunction(runtime, "getAppKeys");
+        auto appKeys =
+            getAppKeys.callWithThis(runtime, appRegistry).asObject(runtime).asArray(runtime);
 
-    auto length = appKeys.length(runtime);
-    result.reserve(length);
+        auto length = appKeys.length(runtime);
+        result.reserve(length);
 
-    auto logBox = String::createFromAscii(runtime, "LogBox", 6);
-    for (size_t i = 0; i < length; ++i) {
-        auto value = appKeys.getValueAtIndex(runtime, i);
-        if (!value.isString()) {
-            continue;
+        auto logBox = String::createFromAscii(runtime, "LogBox", 6);
+        for (size_t i = 0; i < length; ++i) {
+            auto value = appKeys.getValueAtIndex(runtime, i);
+            if (!value.isString()) {
+                continue;
+            }
+
+            auto appKey = value.toString(runtime);
+            if (String::strictEquals(runtime, appKey, logBox)) {
+                // Ignore internal app keys
+                continue;
+            }
+
+            result.push_back(appKey.utf8(runtime));
         }
-
-        auto appKey = value.toString(runtime);
-        if (String::strictEquals(runtime, appKey, logBox)) {
-            // Ignore internal app keys
-            continue;
-        }
-
-        result.push_back(appKey.utf8(runtime));
+    } catch (...) {
+        // Ignore - if we get here, Metro will eventually throw an invariant violation:
+        // Module AppRegistry is not a registered callable module (calling runApplication).
     }
 
     return result;