added onAndGet method

__tests__/index-spec.js

@@ -55,4 +55,16 @@ describe("Onemitter spec", () => {
         const o1 = __1.default({ value: "test" });
         expect(o1.get()).toBe("test");
     });
+    it("onAndGet should call immediately if value existing", () => {
+        const o1 = __1.default({ value: "test" });
+        const cb = jest.fn();
+        o1.onAndGet(cb);
+        expect(cb.mock.calls).toEqual([["test"]]);
+    });
+    it("onAndGet should not call immediately if value not existing", () => {
+        const o1 = __1.default();
+        const cb = jest.fn();
+        o1.onAndGet(cb);
+        expect(cb.mock.calls.length).toBe(0);
+    });
 });

__tests__/index-spec.ts

@@ -53,4 +53,17 @@ describe("Onemitter spec", () => {
         const o1 = onemitter({ value: "test" });
         expect(o1.get()).toBe("test");
     });
+
+    it("onAndGet should call immediately if value existing", () => {
+        const o1 = onemitter({ value: "test" });
+        const cb = jest.fn();
+        o1.onAndGet(cb);
+        expect(cb.mock.calls).toEqual([["test"]]);
+    });
+    it("onAndGet should not call immediately if value not existing", () => {
+        const o1 = onemitter();
+        const cb = jest.fn();
+        o1.onAndGet(cb);
+        expect(cb.mock.calls.length).toBe(0);
+    });
 });

index.js

@@ -24,6 +24,12 @@ class Onemitter {
     on(cb) {
         this.listeners.push(cb);
     }
+    onAndGet(cb) {
+        this.listeners.push(cb);
+        if ("value" in this.store) {
+            cb(this.store.value);
+        }
+    }
     off(cb) {
         this.listeners = this.listeners.filter((c) => c !== cb);
     }

index.ts

@@ -22,6 +22,12 @@ export class Onemitter<T> {
     public on(cb: (value: T) => any) {
         this.listeners.push(cb);
     }
+    public onAndGet(cb: (value: T) => any) {
+        this.listeners.push(cb);
+        if ("value" in this.store) {
+            cb(this.store.value as any);
+        }
+    }
     public off(cb: (value: T) => any) {
         this.listeners = this.listeners.filter((c) => c !== cb);
     }

package.json

@@ -19,11 +19,11 @@
   },
   "homepage": "https://github.com/arvitaly/onemitter#readme",
   "devDependencies": {
-    "@types/jest": "^22.1.4",
+    "@types/jest": "^22.2.2",
     "coveralls": "^3.0.0",
-    "jest": "^22.4.2",
+    "jest": "^22.4.3",
     "tslint": "^5.9.1",
-    "typescript": "^2.7.2"
+    "typescript": "^2.8.1"
   },
   "jest": {}
 }