feat(remote-config): support minimumFetchInterval config setting (#2789)

Prior to this change the only RemoteConfig setting that was available is
the isDeveloperModeEnabled setting.  On iOS this setting causes react
native firebase to call `initWithDeveloperModeEnabled` - which [is
deprecated](https://github.com/firebase/firebase-ios-sdk/blob/master/FirebaseRemoteConfig/Sources/Public/FIRRemoteConfig.h#L148-L149)
and appears to do nothing.

This adds support for the minimumFetchInterval setting, which is the
recommended way to control the fetch timeout now (on iOS at least)

packages/remote-config/android/src/main/java/io/invertase/firebase/config/UniversalFirebaseConfigModule.java

@@ -69,6 +69,10 @@ public class UniversalFirebaseConfigModule extends UniversalFirebaseModule {
     return Tasks.call(getExecutor(), () -> {
       FirebaseRemoteConfigSettings.Builder configSettingsBuilder = new FirebaseRemoteConfigSettings.Builder();
       configSettingsBuilder.setDeveloperModeEnabled(configSettings.getBoolean("isDeveloperModeEnabled"));
+      if (configSettings.containsKey("minimumFetchInterval")) {
+        double fetchInterval = configSettings.getDouble("minimumFetchInterval");
+        configSettingsBuilder.setMinimumFetchIntervalInSeconds((long)fetchInterval);
+      }
       FirebaseRemoteConfig.getInstance().setConfigSettings(configSettingsBuilder.build());
       return null;
     });
@@ -174,6 +178,7 @@ public class UniversalFirebaseConfigModule extends UniversalFirebaseModule {
     appConstants.put("lastFetchTime", remoteConfigInfo.getFetchTimeMillis());
     appConstants.put("isDeveloperModeEnabled", remoteConfigSettings.isDeveloperModeEnabled());
     appConstants.put("lastFetchStatus", lastFetchStatusToString(remoteConfigInfo.getLastFetchStatus()));
+    appConstants.put("minimumFetchInterval", remoteConfigSettings.getMinimumFetchIntervalInSeconds());
 
     return appConstants;
   }

packages/remote-config/e2e/config.e2e.js

@@ -120,6 +120,14 @@ describe('remoteConfig()', () => {
       firebase.remoteConfig().isDeveloperModeEnabled.should.equal(false);
     });
 
+    it('minimumFetchInterval sets correctly', async () => {
+      await firebase
+        .remoteConfig()
+        .setConfigSettings({ isDeveloperModeEnabled: true, minimumFetchInterval: 300 });
+
+      firebase.remoteConfig().minimumFetchInterval.should.be.equal(300);
+    });
+
     it('it throws if no args', async () => {
       try {
         await firebase.remoteConfig().setConfigSettings();
@@ -151,6 +159,18 @@ describe('remoteConfig()', () => {
         return Promise.resolve();
       }
     });
+
+    it('throws if minimumFetchInterval is not a number', async () => {
+      try {
+        await firebase
+          .remoteConfig()
+          .setConfigSettings({ isDeveloperModeEnabled: true, minimumFetchInterval: 'potato' });
+        return Promise.reject(new Error('Did not throw'));
+      } catch (error) {
+        error.message.should.containEql("'settings.minimumFetchInterval' must be a number value");
+        return Promise.resolve();
+      }
+    });
   });
 
   describe('getAll()', () => {

packages/remote-config/ios/RNFBConfig/RNFBConfigModule.m

@@ -141,6 +141,11 @@ RCT_EXPORT_METHOD(setConfigSettings:
 ) {
   FIRRemoteConfigSettings *remoteConfigSettings =
       [[FIRRemoteConfigSettings alloc] initWithDeveloperModeEnabled:[configSettings[@"isDeveloperModeEnabled"] boolValue]];
+
+  if ([configSettings objectForKey:@"minimumFetchInterval"]) {
+    remoteConfigSettings.minimumFetchInterval = [configSettings[@"minimumFetchInterval"] doubleValue];
+  }
+
   [FIRRemoteConfig remoteConfig].configSettings = remoteConfigSettings;
   resolve([self resultWithConstants:[NSNull null]]);
 }
@@ -184,6 +189,7 @@ RCT_EXPORT_METHOD(setDefaultsFromResource:
   NSDate *lastFetchTime = remoteConfig.lastFetchTime;
   BOOL isDeveloperModeEnabled = [RCTConvert BOOL:@([remoteConfig configSettings].isDeveloperModeEnabled)];
   NSString *lastFetchStatus = convertFIRRemoteConfigFetchStatusToNSString(remoteConfig.lastFetchStatus);
+  double minimumFetchInterval = [RCTConvert double:@([remoteConfig configSettings].minimumFetchInterval)];
 
   NSMutableDictionary *values = [NSMutableDictionary new];
   NSSet *keys = [[FIRRemoteConfig remoteConfig] keysWithPrefix:nil];
@@ -205,6 +211,7 @@ RCT_EXPORT_METHOD(setDefaultsFromResource:
       @"lastFetchStatus": lastFetchStatus,
       @"isDeveloperModeEnabled": @(isDeveloperModeEnabled),
       @"lastFetchTime": @(round([lastFetchTime timeIntervalSince1970] * 1000.0)),
+      @"minimumFetchInterval": @(minimumFetchInterval)
   };
 }
 

packages/remote-config/lib/index.d.ts

@@ -242,6 +242,10 @@ export namespace FirebaseRemoteConfigTypes {
      * experience.
      */
     isDeveloperModeEnabled: boolean;
+    /**
+     * The time that remote config should cache flags for.
+     */
+    minimumFetchInterval?: number;
   }
 
   /**

packages/remote-config/lib/index.js

@@ -119,6 +119,10 @@ class FirebaseConfigModule extends FirebaseModule {
     return this._isDeveloperModeEnabled;
   }
 
+  get minimumFetchInterval() {
+    return this._minimumFetchInterval;
+  }
+
   setConfigSettings(settings = {}) {
     if (!isObject(settings) || !hasOwnProperty(settings, 'isDeveloperModeEnabled')) {
       throw new Error(
@@ -132,6 +136,15 @@ class FirebaseConfigModule extends FirebaseModule {
       );
     }
 
+    if (
+      hasOwnProperty(settings, 'minimumFetchInterval') &&
+      !isNumber(settings.minimumFetchInterval)
+    ) {
+      throw new Error(
+        "firebase.remoteConfig().setConfigSettings(): 'settings.minimumFetchInterval' must be a number value.",
+      );
+    }
+
     return this._promiseWithConstants(this.native.setConfigSettings(settings));
   }
 
@@ -197,6 +210,7 @@ class FirebaseConfigModule extends FirebaseModule {
     this._lastFetchStatus = constants.lastFetchStatus;
     this._values = convertNativeConfigValues(constants.values);
     this._isDeveloperModeEnabled = constants.isDeveloperModeEnabled;
+    this._minimumFetchInterval = constants.minimumFetchInterval;
   }
 
   _promiseWithConstants(promise) {

packages/remote-config/lib/index.js.flow

@@ -204,6 +204,10 @@ export interface ConfigSettings {
    * experience.
    */
   isDeveloperModeEnabled: boolean;
+  /**
+   * The time that remote config should cache flags for.
+   */
+  minimumFetchInterval?: number;
 }
 
 /**