@perfective/maybe - npm Package Compare versions

Comparing version 0.3.1 to 0.3.2

dist/maybe/maybe.d.ts

@@ -11,2 +11,4 @@ import { Predicate, Present, TypeGuard, Unary } from '../value/value';
     protected constructor(value: T | null | undefined, none: <U>() => Nothing<U> | Nil<U>);
+    onto<U>(bind: (value: T) => Maybe<U>): Maybe<U>;
+    to<U>(map: (value: T) => U | null | undefined): Maybe<U>;
     that(is: Predicate<T>): Maybe<T>;
@@ -44,3 +46,3 @@ with<V extends T>(is: TypeGuard<T, V>): Maybe<V>;
 export declare function nullable<T>(value: T | null): Maybe<T>;
-export declare function optional<T>(value?: T): Maybe<T>;
+export declare function optional<T>(value: T | undefined): Maybe<T>;
 export declare function maybeOf<T>(value: Maybe<T> | T | null | undefined): Maybe<T>;
@@ -47,0 +49,0 @@ export declare function fallbackTo<T>(fallback: Fallback<T>): T;

dist/maybe/maybe.js

@@ -22,2 +22,14 @@ "use strict";
     }
+    Maybe.prototype.onto = function (bind) {
+        if (value_1.isPresent(this.value)) {
+            return bind(this.value);
+        }
+        return this.none();
+    };
+    Maybe.prototype.to = function (map) {
+        if (value_1.isPresent(this.value)) {
+            return maybe(map(this.value));
+        }
+        return this.none();
+    };
     Maybe.prototype.that = function (is) {
@@ -24,0 +36,0 @@ if (value_1.isPresent(this.value)) {

dist/maybe/maybe.spec.js

@@ -52,3 +52,3 @@ "use strict";
     it('equals nothing() when value is undefined', function () {
-        expect(maybe_1.optional())
+        expect(maybe_1.optional(undefined))
             .toStrictEqual(maybe_1.nothing());
@@ -74,2 +74,30 @@ });
     });
+    describe('onto', function () {
+        it('satisfies left identity monad law', function () {
+            expect(maybe_1.just(3.14).onto(justDecimal))
+                .toStrictEqual(justDecimal(3.14));
+        });
+        it('satisfies right identity monad law', function () {
+            expect(maybe_1.just(3.14).onto(maybe_1.maybe))
+                .toStrictEqual(maybe_1.just(3.14));
+        });
+        it('satisfies associativity monad law', function () {
+            expect(maybe_1.just(3.14).onto(function (x) { return justDecimal(x).onto(split); }))
+                .toStrictEqual(maybe_1.just(3.14).onto(justDecimal).onto(split));
+        });
+    });
+    describe('to', function () {
+        it('returns Just next value when the bind function returns a present value', function () {
+            expect(maybe_1.just(3.14).to(decimal))
+                .toStrictEqual(maybe_1.just(decimal(3.14)));
+        });
+        it('returns Nothing when the bind function returns undefined', function () {
+            expect(maybe_1.just(3.14).to(function () { return undefined; }))
+                .toStrictEqual(maybe_1.nothing());
+        });
+        it('returns Nil when the bind function returns null', function () {
+            expect(maybe_1.just(3.14).to(function () { return null; }))
+                .toStrictEqual(maybe_1.nil());
+        });
+    });
     describe('then', function () {
@@ -269,2 +297,22 @@ it('satisfies left identity monad law', function () {
     });
+    describe('onto', function () {
+        it('satisfies left identity monad law for an undefined value', function () {
+            expect(maybe_1.nothing().onto(justDecimal))
+                .toStrictEqual(maybe_1.nothing());
+        });
+        it('satisfies right identity monad law', function () {
+            expect(maybe_1.nothing().onto(maybe_1.maybe))
+                .toStrictEqual(maybe_1.nothing());
+        });
+        it('satisfies associativity monad law', function () {
+            expect(maybe_1.nothing().onto(function (x) { return justDecimal(x).onto(split); }))
+                .toStrictEqual(maybe_1.nothing().onto(justDecimal).onto(split));
+        });
+    });
+    describe('to', function () {
+        it('skips the mapping function', function () {
+            expect(maybe_1.nothing().to(decimal))
+                .toStrictEqual(maybe_1.nothing());
+        });
+    });
     describe('then', function () {
@@ -410,2 +458,22 @@ it('satisfies left identity monad law for an undefined value', function () {
     });
+    describe('onto', function () {
+        it('satisfies left identity monad law for an undefined value', function () {
+            expect(maybe_1.nil().onto(justDecimal))
+                .toStrictEqual(maybe_1.nil());
+        });
+        it('satisfies right identity monad law', function () {
+            expect(maybe_1.nil().onto(maybe_1.maybe))
+                .toStrictEqual(maybe_1.nil());
+        });
+        it('satisfies associativity monad law', function () {
+            expect(maybe_1.nil().onto(function (x) { return justDecimal(x).onto(split); }))
+                .toStrictEqual(maybe_1.nil().onto(justDecimal).onto(split));
+        });
+    });
+    describe('to', function () {
+        it('skips the mapping function', function () {
+            expect(maybe_1.nil().to(decimal))
+                .toStrictEqual(maybe_1.nil());
+        });
+    });
     describe('then', function () {
@@ -412,0 +480,0 @@ it('satisfies left identity monad law for an undefined value', function () {

package.json

 {
     "name": "@perfective/maybe",
-    "version": "0.3.1",
+    "version": "0.3.2",
     "description": "Maybe monad-like container",
@@ -5,0 +5,0 @@ "author": "Andrey Mikheychik <[e-mail]>",

No alert changes

Improved metrics

Total package byte prevSize

144407

increased by5.18%

Lines of code

1719

increased by5.01%

No dependency changes