Merge branch 'fix/undefined-as-operation-result' into release/0.1

CHANGELOG.md

@@ -4,6 +4,11 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
+## [0.1.2] - 2018-03-29
+### Fixed
+
+- Undefined leakage as identity from operation provided to #map().
+
 ## [0.1.1] - 2018-03-24
 ### Fixed
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@ama-team/optional",
-  "version": "0.1.1",
+  "version": "0.1.2",
   "main": "dist/index.js",
   "repository": "git@github.com:ama-team/ts-optional.git",
   "author": "AMA Team <dev@amagroup.ru>",

src/Optional.ts

@@ -32,7 +32,10 @@ export class Optional<T> implements IOptional<T> {
     }
 
     public map<V>(operation: (identity: T) => V | null): Optional<V> {
-        return new Optional(this.identity !== null ? operation(this.identity) : null);
+        if (this.identity === null) {
+            return Optional.empty();
+        }
+        return Optional.ofNullable(operation(this.identity));
     }
 
     public flatMap<V>(transformer: (identity: T) => IOptional<V>): Optional<V> {
@@ -52,11 +55,11 @@ export class Optional<T> implements IOptional<T> {
         return this;
     }
 
-    public ifEmpty(action: () => void): IOptional<T> {
+    public ifEmpty(action: () => void): Optional<T> {
         if (this.identity === null) {
             action();
         }
-        return this as IOptional<T>;
+        return this;
     }
 
     public peek(consumer: (identity: (T | null)) => void): Optional<T> {
@@ -84,14 +87,14 @@ export class Optional<T> implements IOptional<T> {
         if (this.identity !== null) {
             return this;
         }
-        return new Optional<T>(value);
+        return Optional.ofNullable(value);
     }
 
     public rescueWith(producer: () => T): Optional<T> {
         if (this.identity !== null) {
             return this;
         }
-        return new Optional<T>(producer());
+        return Optional.ofNullable(producer());
     }
 
     public orElse(fallback: T): T {

test/unit/Optional.spec.ts

@@ -198,6 +198,14 @@ describe('/Optional.ts', () => {
                 Optional.empty().map(transformer);
                 expect(transformer.callCount).to.eq(0);
             });
+
+            it('handles undefined result correctly', () => {
+                const transformer = Sinon.stub().returns(undefined);
+                const inspected = Optional.of(42).map(transformer);
+                expect(inspected.empty).to.eq(true);
+                expect(inspected.present).to.eq(false);
+                expect(() => inspected.get()).to.throw(TypeError);
+            });
         });
 
         describe('#flatMap', () => {