chore: simplify settings.gradle script, extend docs

Author: artus9033

apps/test-app/android/settings.gradle

@@ -19,3 +19,7 @@ apply(from: {
     throw new GradleException("Could not find `react-native-test-app`");
 }())
 applyTestAppSettings(settings)
+
+// customize the path to match your node_modules location
+apply(from: "../../../node_modules/react-native-node-api/android/consumerSettings.gradle")
+applyNodeAPISettings(settings)

docs/ANDROID.md

@@ -1,13 +1,36 @@
 # Android support
 
-## Building Hermes from source
+## Android setup
+
+### Step 1: `settings.gradle`
+
+Gradle needs special handling to build React Native from source. In your app's `settings.gradle` please include the below:
+
+```groovy
+// customize the path to match your node_modules location
+apply(from: "../../../node_modules/react-native-node-api/android/consumerSettings.gradle")
+applyNodeAPISettings(settings)
+```
+
+### Step 2: script for adjusting environment variables
+
+To integrate automatic setup of Hermes engine, a special env variable (`REACT_NATIVE_OVERRIDE_HERMES_DIR`) must be set to a proper path. Since Gradle does not really support loading `.env` files, this must be automated by the consumer. We provide the script `react-native-node-api vendor-hermes --silent` which will output a single line, the path to Hermes directory.
+
+Each time you run Android Studio, make sure this is in place.
+
+### How it works: building Hermes from source
 
 Because we're using a version of Hermes patched with Node-API support, we need to build React Native from source.
 
+Alternatively, if for whatever reason you want to do it manually, you can do so by exporting this environment variable before Gradle invocation:
+
 ```
-export REACT_NATIVE_OVERRIDE_HERMES_DIR=`npx react-native-node-api vendor-hermes --silent`
+export REACT_NATIVE_OVERRIDE_HERMES_DIR="$(npx react-native-node-api vendor-hermes --silent)"
 ```
 
+> [!TIP]
+> This above automatically done by our script. If you run it from postinstall, there is no need to do this manually.
+
 ## Cleaning your React Native build folders
 
 If you've accidentally built your app without Hermes patched, you can clean things up by deleting the `ReactAndroid` build folder.

docs/IOS.md

@@ -0,0 +1,7 @@
+# iOS support
+
+## iOS setup: script for adjusting environment variables
+
+To integrate automatic setup of Hermes engine, a special env variable (`REACT_NATIVE_OVERRIDE_HERMES_DIR`) must be set to a proper path. We provide the script `react-native-node-api vendor-hermes --silent` which will output a single line, the path to Hermes directory.
+
+Each time you run XCode, make sure this is in place.

package-lock.json

@@ -0,0 +1,22 @@
+import org.gradle.initialization.DefaultSettings
+
+
+ext.applyNodeAPISettings = { DefaultSettings settings ->
+    def searchDirectory = rootDir.toPath()
+    do {
+        def p = searchDirectory.resolve("node_modules/react-native")
+        if (p.toFile().exists()) {
+            println "[RN-NAPI] Found React Native in ${p.toRealPath().toString()}"
+
+            includeBuild(p.toRealPath().toString()) {
+                dependencySubstitution {
+                    substitute(module("com.facebook.react:react-android")).using(project(":packages:react-native:ReactAndroid"))
+                    substitute(module("com.facebook.react:react-native")).using(project(":packages:react-native:ReactAndroid"))
+                    substitute(module("com.facebook.react:hermes-android")).using(project(":packages:react-native:ReactAndroid:hermes-engine"))
+                    substitute(module("com.facebook.react:hermes-engine")).using(project(":packages:react-native:ReactAndroid:hermes-engine"))
+                }
+            }
+            break
+        }
+    } while (searchDirectory = searchDirectory.getParent())
+}