feat(pluck): Support multiple parameters.

cartant · Jan 20, 2018 · 04d1766 · 04d1766
1 parent 090e4aa
commit 04d1766
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Showing 2 changed files with 40 additions and 3 deletions.
diff --git a/source/let/pluck-spec.ts b/source/let/pluck-spec.ts
@@ -22,4 +22,17 @@ describe("let/pluck", () => {
         m.expect(destination).toBeObservable(expected);
         m.expect(source).toHaveSubscriptions(subs);
     }));
+
+    it("should pluck the specified nested key", marbles((m) => {
+
+        interface Letters { a: { b: { c: { d: { e: { f: string } } } } }; }
+
+        const source =  m.cold<Letters>("-t-|", { t: { a: { b: { c: { d: { e: { f: "F" } } } } } } });
+        const subs =                    "^--!";
+        const expected = m.cold<string>("-f-|", { f: "F" });
+
+        const destination = source.pipe(pluck("a", "b", "c", "d", "e", "f"));
+        m.expect(destination).toBeObservable(expected);
+        m.expect(source).toHaveSubscriptions(subs);
+    }));
 });
diff --git a/source/let/pluck.ts b/source/let/pluck.ts
@@ -5,9 +5,33 @@
  */
 
 import { Observable } from "rxjs/Observable";
-import { map } from "rxjs/operators/map";
+import { pluck as untypedPluck } from "rxjs/operators/pluck";
 
-export function pluck<T, K extends keyof T>(key: K): (source: Observable<T>) => Observable<T[K]> {
+export function pluck<T, K1 extends keyof T>(
+    k1: K1
+): (source: Observable<T>) => Observable<T[K1]>;
 
-    return (source) => source.pipe(map((value: T) => value[key]));
+export function pluck<T, K1 extends keyof T, K2 extends keyof T[K1]>(
+    k1: K1, k2: K2
+): (source: Observable<T>) => Observable<T[K1][K2]>;
+
+export function pluck<T, K1 extends keyof T, K2 extends keyof T[K1], K3 extends keyof T[K1][K2]>(
+    k1: K1, k2: K2, k3: K3
+): (source: Observable<T>) => Observable<T[K1][K2][K3]>;
+
+export function pluck<T, K1 extends keyof T, K2 extends keyof T[K1], K3 extends keyof T[K1][K2], K4 extends keyof T[K1][K2][K3]>(
+    k1: K1, k2: K2, k3: K3, k4: K4
+): (source: Observable<T>) => Observable<T[K1][K2][K3][K4]>;
+
+export function pluck<T, K1 extends keyof T, K2 extends keyof T[K1], K3 extends keyof T[K1][K2], K4 extends keyof T[K1][K2][K3], K5 extends keyof T[K1][K2][K3][K4]>(
+    k1: K1, k2: K2, k3: K3, k4: K4, k5: K5
+): (source: Observable<T>) => Observable<T[K1][K2][K3][K4][K5]>;
+
+export function pluck<T, K1 extends keyof T, K2 extends keyof T[K1], K3 extends keyof T[K1][K2], K4 extends keyof T[K1][K2][K3], K5 extends keyof T[K1][K2][K3][K4], K6 extends keyof T[K1][K2][K3][K4][K5]>(
+    k1: K1, k2: K2, k3: K3, k4: K4, k5: K5, k6: K6
+): (source: Observable<T>) => Observable<T[K1][K2][K3][K4][K5][K6]>;
+
+export function pluck<T>(...keys: string[]): (source: Observable<T>) => Observable<any> {
+
+    return (source) => untypedPluck(...keys)(source);
 }