fix(auth): user.metadata uses ISO strings (#3360)

* fix(auth): user.metadata uses ISO strings

* chore(auth): move code to metadata getter

* chore(auth): refactor user.metadata

* test(auth): metadata props are milliseconds

.gitignore

@@ -551,6 +551,7 @@ GoogleService-Info.plist
 # generated file
 RNFBVersion.m
 
+appPlaygrounds/
 app.playground.js
 app.admob.js
 app.smartreply.js

packages/auth/e2e/user.e2e.js

@@ -396,4 +396,23 @@ describe('auth().currentUser', () => {
       await firebase.auth().signOut();
     });
   });
+
+  describe('user.metadata', () => {
+    it("should have the properties 'lastSignInTime' & 'creationTime' which are ISO strings", async () => {
+      const random = Utils.randString(12, '#aA');
+      const email = `${random}@${random}.com`;
+
+      const { user } = await firebase.auth().createUserWithEmailAndPassword(email, random);
+
+      const { metadata } = user;
+
+      should(metadata.lastSignInTime).be.a.String();
+      should(metadata.creationTime).be.a.String();
+
+      new Date(metadata.lastSignInTime).getFullYear().should.equal(new Date().getFullYear());
+      new Date(metadata.creationTime).getFullYear().should.equal(new Date().getFullYear());
+
+      await firebase.auth().currentUser.delete();
+    });
+  });
 });

packages/auth/lib/User.js

@@ -40,7 +40,12 @@ export default class User {
   }
 
   get metadata() {
-    return this._user.metadata;
+    const { metadata } = this._user;
+
+    return {
+      lastSignInTime: new Date(metadata.lastSignInTime).toISOString(),
+      creationTime: new Date(metadata.creationTime).toISOString(),
+    };
   }
 
   get phoneNumber() {

tests/index.android.js

@@ -1,2 +1,4 @@
 require('./app');
+// require('./app.playground');
+// require('./appPlaygrounds/firestore');
 //require('./app.admob');