Merge pull request #13 from abraham/left-right

Make RemoteData generics left/right based

Author: abraham

src/index.test.ts

@@ -42,8 +42,8 @@ test('fold initialized', () => {
   const view = fold(
     initializedMock,
     pendingMock,
-    successMock,
     failureMock,
+    successMock,
   );
 
   view(new Initialized());
@@ -62,8 +62,8 @@ test('fold pending', () => {
   const view = fold(
     initializedMock,
     pendingMock,
-    successMock,
     failureMock,
+    successMock,
   );
 
   view(new Pending());
@@ -82,8 +82,8 @@ test('fold success', () => {
   const view = fold(
     initializedMock,
     pendingMock,
-    successMock,
     failureMock,
+    successMock,
   );
 
   const data = { apple: 'sauce' };
@@ -103,8 +103,8 @@ test('fold failure', () => {
   const view = fold(
     initializedMock,
     pendingMock,
-    successMock,
     failureMock,
+    successMock,
   );
 
   const error = 500;
@@ -125,8 +125,8 @@ test('fold unknown', () => {
   const view = fold(
     initializedMock,
     pendingMock,
-    successMock,
     failureMock,
+    successMock,
   );
 
   expect(() => view(otherMock)).toThrowError('Unknown RemoteData type used');

src/index.ts

@@ -1,4 +1,4 @@
-export type RemoteData<D, E> = Initialized | Pending | Success<D> | Failure<E>;
+export type RemoteData<E, D> = Initialized | Pending | Failure<E> | Success<D>;
 
 export class Initialized {
   private kind = 'Initialized';
@@ -28,13 +28,13 @@ export class Failure<E> {
   }
 }
 
-export function fold<T, D, E>(
+export function fold<T, E, D>(
   initialized: () => T,
   pending: () => T,
-  success: (data: D) => T,
   failure: (error: E) => T,
-): (state: RemoteData<D, E>) => T {
-  return (state: RemoteData<D, E>) => {
+  success: (data: D) => T,
+): (state: RemoteData<E, D>) => T {
+  return (state: RemoteData<E, D>) => {
     if (state instanceof Initialized) {
       return initialized();
     } else if (state instanceof Pending) {