Use domain in context to override RTDB domain

CHANGELOG.md

@@ -0,0 +1 @@
+- Adds support for multi-region RTDB.

spec/providers/database.spec.ts

@@ -424,30 +424,72 @@ describe('Database Functions', () => {
     });
   });
 
-  describe('resourceToInstanceAndPath', () => {
-    it('should return the correct instance and path strings', () => {
-      const [instance, path] = database.resourceToInstanceAndPath(
-        'projects/_/instances/foo/refs/bar'
-      );
+  describe('extractInstanceAndPath', () => {
+    it('should return the correct us-central prod instance and path strings', () => {
+      const [instance, path] = database.extractInstanceAndPath({
+        context: {
+          resource: {
+            name: 'projects/_/instances/foo/refs/bar',
+          },
+        },
+      });
       expect(instance).to.equal('https://foo.firebaseio.com');
       expect(path).to.equal('/bar');
     });
 
+    it('should return the correct staging instance and path strings', () => {
+      const [instance, path] = database.extractInstanceAndPath({
+        context: {
+          resource: {
+            name: 'projects/_/instances/foo/refs/bar',
+          },
+          domain: 'firebaseio-staging.com',
+        },
+      });
+      expect(instance).to.equal('https://foo.firebaseio-staging.com');
+      expect(path).to.equal('/bar');
+    });
+
+    it('should return the correct multi-region instance and path strings', () => {
+      const [instance, path] = database.extractInstanceAndPath({
+        context: {
+          resource: {
+            name: 'projects/_/instances/foo/refs/bar',
+          },
+          domain: 'euw1.firebasedatabase.app',
+        },
+      });
+      expect(instance).to.equal('https://foo.euw1.firebasedatabase.app');
+      expect(path).to.equal('/bar');
+    });
+
     it('should throw an error if the given instance name contains anything except alphanumerics and dashes', () => {
       expect(() => {
-        return database.resourceToInstanceAndPath(
-          'projects/_/instances/a.bad.name/refs/bar'
-        );
+        return database.extractInstanceAndPath({
+          context: {
+            resource: {
+              name: 'projects/_/instances/a.bad.name/refs/bar',
+            },
+          },
+        });
       }).to.throw(Error);
       expect(() => {
-        return database.resourceToInstanceAndPath(
-          'projects/_/instances/a_different_bad_name/refs/bar'
-        );
+        return database.extractInstanceAndPath({
+          context: {
+            resource: {
+              name: 'projects/_/instances/a_different_bad_name/refs/bar',
+            },
+          },
+        });
       }).to.throw(Error);
       expect(() => {
-        return database.resourceToInstanceAndPath(
-          'projects/_/instances/BAD!!!!/refs/bar'
-        );
+        return database.extractInstanceAndPath({
+          context: {
+            resource: {
+              name: 'projects/_/instances/BAD!!!!/refs/bar',
+            },
+          },
+        });
       }).to.throw(Error);
     });
   });
@@ -457,17 +499,22 @@ describe('Database Functions', () => {
     const apps = new appsNamespace.Apps();
 
     const populate = (data: any) => {
-      const [instance, path] = database.resourceToInstanceAndPath(
-        'projects/_/instances/other-subdomain/refs/foo'
-      );
+      const [instance, path] = database.extractInstanceAndPath({
+        context: {
+          resource: {
+            name: 'projects/_/instances/other-subdomain/refs/foo',
+          },
+          domain: 'firebaseio-staging.com',
+        },
+      });
       subject = new database.DataSnapshot(data, path, apps.admin, instance);
     };
 
     describe('#ref: firebase.database.Reference', () => {
       it('should return a ref for correct instance, not the default instance', () => {
         populate({});
         expect(subject.ref.toJSON()).to.equal(
-          'https://other-subdomain.firebaseio.com/foo'
+          'https://other-subdomain.firebaseio-staging.com/foo'
         );
       });
     });
@@ -648,9 +695,13 @@ describe('Database Functions', () => {
       });
 
       it('should return null for the root', () => {
-        const [instance, path] = database.resourceToInstanceAndPath(
-          'projects/_/instances/foo/refs/'
-        );
+        const [instance, path] = database.extractInstanceAndPath({
+          context: {
+            resource: {
+              name: 'projects/_/instances/foo/refs/',
+            },
+          },
+        });
         const snapshot = new database.DataSnapshot(
           null,
           path,

src/providers/database.ts

@@ -215,9 +215,7 @@ export class RefBuilder {
     ) => PromiseLike<any> | any
   ): CloudFunction<DataSnapshot> {
     const dataConstructor = (raw: Event) => {
-      const [dbInstance, path] = resourceToInstanceAndPath(
-        raw.context.resource.name
-      );
+      const [dbInstance, path] = extractInstanceAndPath(raw);
       return new DataSnapshot(
         raw.data.delta,
         path,
@@ -243,9 +241,7 @@ export class RefBuilder {
     ) => PromiseLike<any> | any
   ): CloudFunction<DataSnapshot> {
     const dataConstructor = (raw: Event) => {
-      const [dbInstance, path] = resourceToInstanceAndPath(
-        raw.context.resource.name
-      );
+      const [dbInstance, path] = extractInstanceAndPath(raw);
       return new DataSnapshot(raw.data.data, path, this.apps.admin, dbInstance);
     };
     return this.onOperation(handler, 'ref.delete', dataConstructor);
@@ -271,9 +267,7 @@ export class RefBuilder {
   }
 
   private changeConstructor = (raw: Event): Change<DataSnapshot> => {
-    const [dbInstance, path] = resourceToInstanceAndPath(
-      raw.context.resource.name
-    );
+    const [dbInstance, path] = extractInstanceAndPath(raw);
     const before = new DataSnapshot(
       raw.data.data,
       path,
@@ -293,9 +287,13 @@ export class RefBuilder {
   };
 }
 
-/* Utility function to extract database reference from resource string */
+/**
+ * Utility function to extract database reference from resource string.
+ * The raw event may contain fields not part of the public API.
+ */
 /** @hidden */
-export function resourceToInstanceAndPath(resource: string) {
+export function extractInstanceAndPath(rawEvent: any) {
+  const resource = rawEvent.context.resource.name;
   const resourceRegex = `projects/([^/]+)/instances/([a-zA-Z0-9\-^/]+)/refs(/.+)?`;
   const match = resource.match(new RegExp(resourceRegex));
   if (!match) {
@@ -310,7 +308,14 @@ export function resourceToInstanceAndPath(resource: string) {
       `Expect project to be '_' in a Firebase Realtime Database event`
     );
   }
-  const dbInstance = 'https://' + dbInstanceName + '.firebaseio.com';
+  let domain = 'firebaseio.com';
+  if (_.has(rawEvent, 'context.domain')) {
+    // See go/rtdb-multi-region-function-sdk.
+    // Multi-region RTDB are served from different domains.
+    // Since region is not part of the resource name, it is provided through context.
+    domain = _.get(rawEvent, 'context.domain');
+  }
+  const dbInstance = 'https://' + dbInstanceName + '.' + domain;
   return [dbInstance, path];
 }