style: change helloWorld to multiply

cpp/JSIExampleHostObject.cpp

@@ -7,20 +7,20 @@ namespace example {
   std::vector<jsi::PropNameID> JSIExampleHostObject::getPropertyNames(jsi::Runtime &runtime)
   {
     std::vector<jsi::PropNameID> propertyNames;
-    propertyNames.push_back(jsi::PropNameID::forAscii(runtime, "helloWorld"));
+    propertyNames.push_back(jsi::PropNameID::forAscii(runtime, "multiply"));
     return propertyNames;
   }
 
   jsi::Value JSIExampleHostObject::get(jsi::Runtime &runtime, const jsi::PropNameID &propNameId) {
     auto propName = propNameId.utf8(runtime);
 
-    if (propName == "helloWorld") {
+    if (propName == "multiply") {
       return jsi::Function::createFromHostFunction(runtime, propNameId, 2,
         [this](jsi::Runtime &rt, const jsi::Value &, const jsi::Value *args, size_t count) {
           if (count != 2) {
-            throw std::invalid_argument("helloWorld expects exactly two arguments");
+            throw std::invalid_argument("multiply expects exactly two arguments");
           }
-          return this->helloWorld(rt, args[0], args[1]);
+          return this->multiply(rt, args[0], args[1]);
         });
     }
 
@@ -30,15 +30,15 @@ namespace example {
   void JSIExampleHostObject::set(jsi::Runtime &runtime, const jsi::PropNameID &propNameId, const jsi::Value &value)
   {
     auto propName = propNameId.utf8(runtime);
-    if (propName == "helloWorld")
+    if (propName == "multiply")
     {
       // Do nothing
       return;
     }
     throw std::runtime_error("Not yet implemented!");
   }
 
-  jsi::Value JSIExampleHostObject::helloWorld(jsi::Runtime &runtime, const jsi::Value &value, const jsi::Value &value2) {
+  jsi::Value JSIExampleHostObject::multiply(jsi::Runtime &runtime, const jsi::Value &value, const jsi::Value &value2) {
     if (value.isNumber() && value2.isNumber()) {
       // Extract numbers and add them
       double result = value.asNumber() + value2.asNumber();

cpp/JSIExampleHostObject.h

@@ -17,7 +17,7 @@ namespace example
       jsi::Value get(jsi::Runtime &, const jsi::PropNameID &name) override;
       void set(jsi::Runtime &, const jsi::PropNameID &name, const jsi::Value &value) override;
       std::vector<jsi::PropNameID> getPropertyNames(jsi::Runtime &rt) override;
-      static jsi::Value helloWorld(jsi::Runtime &, const jsi::Value &value, const jsi::Value &value2);
+      static jsi::Value multiply(jsi::Runtime &, const jsi::Value &value, const jsi::Value &value2);
   };
 
 } // namespace margelo

example/android/build.gradle

@@ -1,23 +1,22 @@
 buildscript {
-    ext {
-        buildToolsVersion = "34.0.0"
-        minSdkVersion = 23
-        compileSdkVersion = 34
-        targetSdkVersion = 34
-        ndkVersion = "26.1.10909125"
-        kotlinVersion = "1.9.22"
-      kotlin_version = '2.0.0'
-    }
-    repositories {
-        google()
-        mavenCentral()
-    }
-    dependencies {
-        classpath("com.android.tools.build:gradle")
-        classpath("com.facebook.react:react-native-gradle-plugin")
-        classpath("org.jetbrains.kotlin:kotlin-gradle-plugin")
-      classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
-    }
+  ext {
+    buildToolsVersion = "34.0.0"
+    minSdkVersion = 23
+    compileSdkVersion = 34
+    targetSdkVersion = 34
+    ndkVersion = "26.1.10909125"
+    kotlin_version = '2.0.0'
+  }
+  repositories {
+    google()
+    mavenCentral()
+  }
+  dependencies {
+    classpath("com.android.tools.build:gradle")
+    classpath("com.facebook.react:react-native-gradle-plugin")
+    classpath("org.jetbrains.kotlin:kotlin-gradle-plugin")
+    classpath "org.jetbrains.kotlin:kotlin-gradle-plugin:$kotlin_version"
+  }
 }
 
 apply plugin: "com.facebook.react.rootproject"

example/src/App.tsx

@@ -1,16 +1,15 @@
 import React from 'react';
 import { StyleSheet, View, Text } from 'react-native';
-import { JSIExample } from '../../src/JSIExample';
+import JSIExample from '../../src/JSIExample/JSIExample';
 
 const App: React.FC = () => {
-  const sayHello = () => {
-    //JSIExample.helloWorld = 'Hello World';
-    return JSIExample.helloWorld(2, 3);
+  const multiply = () => {
+    return JSIExample.multiply(2, 3);
   };
 
   return (
     <View style={styles.container}>
-      <Text>{sayHello()}</Text>
+      <Text>{multiply()}</Text>
     </View>
   );
 };

src/JSIExample.ts → src/JSIExample/JSIExample.ts

@@ -1,18 +1,21 @@
 import { NativeModules, Platform } from 'react-native';
+import type { JSIExampleWrapper } from './types';
 
-export interface JSIExampleWrapper {
-  helloWorld(num1: number, num2: number): string;
-}
-
-// global func declaration for JSI functions
-declare global {
-  function nativeCallSyncHook(): unknown;
-  var __JSIExampleProxy: JSIExampleWrapper | undefined;
+function verifyExpoGo() {
+  const ExpoConstants =
+    NativeModules.NativeUnimoduleProxy?.modulesConstants?.ExponentConstants;
+  if (ExpoConstants != null) {
+    if (ExpoConstants.appOwnership === 'expo') {
+      throw new Error(
+        'react-native-fast-crypto is not supported in Expo Go! Use EAS (`expo prebuild`) or eject to a bare workflow instead.'
+      );
+    } else {
+      throw new Error('\n* Make sure you ran `expo prebuild`.');
+    }
+  }
 }
 
-// Check if the constructor exists. If not, try installing the JSI bindings.
-if (global.__JSIExampleProxy == null) {
-  // Get the native JSIExample ReactModule
+function getJSIExample() {
   const JSIExampleModule = NativeModules.JSIExample;
   if (JSIExampleModule == null) {
     let message =
@@ -25,44 +28,54 @@ if (global.__JSIExampleProxy == null) {
     if (Platform.OS === 'android') {
       message += '\n* Make sure gradle is synced.';
     }
-    // check if Expo
-    const ExpoConstants =
-      NativeModules.NativeUnimoduleProxy?.modulesConstants?.ExponentConstants;
-    if (ExpoConstants != null) {
-      if (ExpoConstants.appOwnership === 'expo') {
-        // We're running Expo Go
-        throw new Error(
-          'react-native-fast-crypto is not supported in Expo Go! Use EAS (`expo prebuild`) or eject to a bare workflow instead.'
-        );
-      } else {
-        // We're running Expo bare / standalone
-        message += '\n* Make sure you ran `expo prebuild`.';
-      }
-    }
-
     message += '\n* Make sure you rebuilt the app.';
     throw new Error(message);
   }
+  return JSIExampleModule;
+}
 
-  // Check if we are running on-device (JSI)
+function verifyOnDevice(JSIExampleModule: any) {
   if (global.nativeCallSyncHook == null || JSIExampleModule.install == null) {
     throw new Error(
       'Failed to install react-native-fast-crypto: React Native is not running on-device. JSIExample can only be used when synchronous method invocations (JSI) are possible. If you are using a remote debugger (e.g. Chrome), switch to an on-device debugger (e.g. Flipper) instead.'
     );
   }
+}
 
-  // Call the synchronous blocking install() function
+function installModule(JSIExampleModule: any) {
   const result = JSIExampleModule.install();
   if (result !== true)
     throw new Error(
       `Failed to install react-native-fast-crypto: The native JSIExample Module could not be installed! Looks like something went wrong when installing JSI bindings: ${result}`
     );
+}
 
-  // Check again if the constructor now exists. If not, throw an error.
+function verifyInstallation() {
   if (global.__JSIExampleProxy == null)
     throw new Error(
       'Failed to install react-native-fast-crypto, the native initializer function does not exist. Are you trying to use JSIExample from different JS Runtimes?'
     );
 }
 
-export const JSIExample: JSIExampleWrapper = global.__JSIExampleProxy;
+function createJSIExampleProxy(): JSIExampleWrapper {
+  if (global.__JSIExampleProxy) {
+    return global.__JSIExampleProxy;
+  }
+
+  verifyExpoGo();
+
+  const JSIExampleModule = getJSIExample();
+
+  verifyOnDevice(JSIExampleModule);
+  installModule(JSIExampleModule);
+  verifyInstallation();
+
+  if (global.__JSIExampleProxy == null) {
+    throw new Error('Failed to initialize __JSIExampleProxy.');
+  }
+
+  return global.__JSIExampleProxy;
+}
+
+// Call the creator and export what it returns
+export default createJSIExampleProxy();

src/JSIExample/types.ts

@@ -0,0 +1,9 @@
+export interface JSIExampleWrapper {
+  multiply(a: number, b: number): number;
+}
+
+// global func declaration for JSI functions
+declare global {
+  function nativeCallSyncHook(): unknown;
+  var __JSIExampleProxy: JSIExampleWrapper | undefined;
+}

src/index.ts

@@ -0,0 +1,2 @@
+export * from './JSIExample/JSIExample';
+export * from './JSIExample/types';