refator(db): add remove method

Author: davideast

src/database/interfaces.ts

@@ -7,10 +7,10 @@ export interface ListReference<T> {
   query: DatabaseQuery;
   valueChanges<T>(events?: ChildEvent[]): Observable<T[]>;
   snapshotChanges<T>(events?: ChildEvent[]): Observable<DatabaseSnapshot[]>;
-  update(item: FirebaseOperation, data: T): Promise<any>;
-  set(item: FirebaseOperation, data: T): Promise<any>;
-  push(data: T): Promise<any>;
-  remove(item: FirebaseOperation): Promise<any>;
+  update(item: FirebaseOperation, data: T): Promise<void>;
+  set(item: FirebaseOperation, data: T): Promise<void>;
+  push(data: T): firebase.database.ThenableReference;
+  remove(item?: FirebaseOperation): Promise<any>;
 }
 
 export interface ObjectReference<T> {
@@ -20,10 +20,10 @@ export interface ObjectReference<T> {
 }
 
 export interface FirebaseOperationCases {
-  stringCase: () => firebase.Promise<void>;
-  firebaseCase?: () => firebase.Promise<void>;
-  snapshotCase?: () => firebase.Promise<void>;
-  unwrappedSnapshotCase?: () => firebase.Promise<void>;
+  stringCase: () => Promise<void | any>;
+  firebaseCase?: () => Promise<void | any>;
+  snapshotCase?: () => Promise<void | any>;
+  unwrappedSnapshotCase?: () => Promise<void | any>;
 }
 
 export type QueryFn = (ref: DatabaseReference) => DatabaseQuery;

src/database/list/data-operation.ts

@@ -3,7 +3,7 @@ import { DatabaseReference, FirebaseOperation, DatabaseSnapshot } from '../inter
 import { checkOperationCases } from '../utils';
 
 export function createDataOperationMethod<T>(ref: DatabaseReference, operation: string) {
-  return function dataOperation<T>(item: FirebaseOperation, value: T): Promise<any> {
+  return function dataOperation<T>(item: FirebaseOperation, value: T) {
     return checkOperationCases(item, {
       stringCase: () => ref.child(<string>item)[operation](value),
       firebaseCase: () => (<DatabaseReference>item)[operation](value),

src/database/list/remove.ts

@@ -3,10 +3,16 @@ import { checkOperationCases } from '../utils';
 import { createDataOperationMethod } from './data-operation';
 import { database, Promise } from 'firebase/app';
 
+// TODO(davideast): Find out why TS thinks this returns firebase.Primise
+// instead of Promise.
 export function createRemoveMethod(ref: DatabaseReference) {
-  return function remove(item?: FirebaseOperation) {
-    if(!item) { return ref.remove(); }
-    return createDataOperationMethod(ref, 'remove')(item, null)
+  return function remove(item?: FirebaseOperation): any {
+    if(!item) { return ref.remove() as any; }
+    return checkOperationCases(item, {
+      stringCase: () => ref.child(<string>item).remove() as any,
+      firebaseCase: () => (<DatabaseReference>item).remove() as any,
+      snapshotCase: () => (<DatabaseSnapshot>item).ref.remove() as any
+    }) as any;
   }
 }
 

src/database/utils.ts

@@ -2,11 +2,19 @@ import * as firebase from 'firebase/app';
 import { Subscription } from 'rxjs/Subscription';
 import { Scheduler } from 'rxjs/Scheduler';
 import { queue } from 'rxjs/scheduler/queue';
-import { PathReference, DatabaseReference } from './interfaces';
+import { PathReference, DatabaseReference, FirebaseOperation, FirebaseOperationCases } from './interfaces';
 import { FirebaseApp } from 'angularfire2';
 
 const REGEX_ABSOLUTE_URL = /^[a-z]+:\/\/.*/;
 
+export function isString(value: any): boolean {
+  return typeof value === 'string';
+}
+
+export function isFirebaseDataSnapshot(value: any): boolean {
+  return typeof value.exportVal === 'function';
+}
+
 export function isNil(obj: any): boolean {
   return obj === undefined || obj === null;
 }
@@ -56,15 +64,13 @@ export function getRef(app: FirebaseApp, pathRef: PathReference): DatabaseRefere
   return app.database().ref(path);
 }
 
-export function checkOperationCases(item: FirebaseOperation, cases: FirebaseOperationCases) : firebase.Promise<void> {
-  if (utils.isString(item)) {
+export function checkOperationCases(item: FirebaseOperation, cases: FirebaseOperationCases) : Promise<void | any> {
+  if (isString(item)) {
     return cases.stringCase();
-  } else if (utils.isFirebaseRef(item)) {
+  } else if (isFirebaseRef(item)) {
     return cases.firebaseCase!();
-  } else if (utils.isFirebaseDataSnapshot(item)) {
+  } else if (isFirebaseDataSnapshot(item)) {
     return cases.snapshotCase!();
-  } else if (utils.isAFUnwrappedSnapshot(item)) {
-    return cases.unwrappedSnapshotCase!()
   }
-  throw new Error(`Method requires a key, snapshot, reference, or unwrapped snapshot. Got: ${typeof item}`);
-}
+  throw new Error(`Method requires a key, snapshot, reference. Got: ${typeof item}`);
+}