docs: make it clear what platform support is required

.github/workflows/create_test_patches.yml

@@ -39,7 +39,7 @@ jobs:
       #        prior version (18.17.1) to see if it stabilizes
       - uses: actions/setup-node@v4
         with:
-          node-version: 18.17.1
+          node-version: 20
 
       - uses: actions/cache/restore@v4
         name: Yarn Cache Restore

.spellcheck.dict.txt

@@ -101,6 +101,7 @@ IPs
 isTesterSignedIn
 javascript
 Javascript
+JDK
 JS
 JSON
 lastDocument

docs/platforms.md

@@ -8,8 +8,13 @@ next: /release-notes
 
 By default React Native Firebase supports multiple platforms using the native Firebase SDK for the specific platform:
 
-- Android
-- iOS
+| Platform | Minimum Version                      |
+| -------- | ------------------------------------ |
+| Android  | 5.0 (Lollipop) without Firebase Auth |
+|          | 6.0 (Marshmallow) with Firebase Auth |
+| iOS      | 13.0                                 |
+
+**Important** - To compile your application for Android, you will need a minimum JDK (Java Development Kit) version of `>= 17`.
 
 However, for platforms that we don't provide a Native Module for, React Native Firebase instead implements a fallback Firebase JS SDK implementation to support
 these 'Other' platforms, e.g.;

packages/app/android/build.gradle

@@ -1,4 +1,5 @@
 import io.invertase.gradle.common.PackageJson
+import org.gradle.internal.jvm.Jvm
 
 buildscript {
   // The Android Gradle plugin is only required when opening the android folder stand-alone.
@@ -105,6 +106,22 @@ dependencies {
   implementation "com.google.android.gms:play-services-auth:${ReactNative.ext.getVersion("play", "play-services-auth")}"
 }
 
+def jvmVersion = Jvm.current().javaVersion?.majorVersion
+// if it cannot get version, just allow it to pass. This is just a helper for developers
+if ((jvmVersion?.toInteger() ?: 17) < 17) {
+  println("\n\n\n")
+  println("**************************************************************************************************************")
+  println("\n\n\n")
+  println("ERROR: React Native Firebase builds with a minimum JVM version 17. We test with JVM 17 and 21.")
+  println("  Incompatible major version detected: '" + jvmVersion + "'")
+  println("\n\n\n")
+  println("  If you receive this error because you want to use a different JDK, we may accept PRs to support new versions.")
+  println("\n\n\n")
+  println("**************************************************************************************************************")
+  println("\n\n\n")
+  System.exit(1)
+}
+
 ReactNative.shared.applyPackageVersion()
 ReactNative.shared.applyDefaultExcludes()
 ReactNative.module.applyAndroidVersions()