Add tests

Author: strax

package.json

@@ -12,13 +12,30 @@
     "watch": "tsc --watch"
   },
   "devDependencies": {
+    "@types/flux-standard-action": "^0.5.31",
     "@types/jest": "^21.1.8",
+    "flux-standard-action": "^2.0.0",
     "jest": "^21.2.1",
     "redux": "^3.7.2",
+    "redux-thunk": "^2.2.0",
+    "ts-jest": "^21.2.4",
     "typescript": "^2.6.2"
   },
   "peerDependencies": {
     "jest": "^21.2.1",
     "redux": "^3.7.2"
+  },
+  "jest": {
+    "transform": {
+      "^.+\\.tsx?$": "ts-jest"
+    },
+    "testRegex": "/test/.+\\.test\\.(tsx?)$",
+    "moduleFileExtensions": [
+      "ts",
+      "tsx",
+      "js",
+      "jsx",
+      "json"
+    ]
   }
 }

src/index.ts

@@ -1,11 +1,11 @@
 import { Reducer, Store, createStore } from "redux";
 
-export interface Action {
-  type: any;
-  payload: any;
-};
+export type Action = {
+  type: any,
+  payload: any
+}
 
-export default class ReducerTestContext<S> {
+export class ReducerTestContext<S> {
   constructor(
     private readonly reducer: Reducer<S>,
     private readonly defaultState: S
@@ -55,7 +55,7 @@ export default class ReducerTestContext<S> {
   }
 }
 
-export function reducerTest<S>(
+export default function reducerTest<S>(
   reducer: Reducer<S | undefined>,
   defaultState?: S
 ) {

test/__snapshots__/index.test.ts.snap

@@ -0,0 +1,27 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`reducer SET_A("other a") matches snapshot 1`] = `
+Object {
+  "a": "other a",
+  "d": 0,
+}
+`;
+
+exports[`reducer matches snapshot 1`] = `
+Array [
+  Object {
+    "a": "a",
+    "b": Object {
+      "c": true,
+    },
+    "d": 0,
+  },
+  Object {
+    "a": "some other",
+    "b": Object {
+      "c": true,
+    },
+    "d": 0,
+  },
+]
+`;

test/index.test.ts

@@ -0,0 +1,7 @@
+import reducer, {setA, setB } from "./reducer";
+import reducerTest from "../src/index";
+
+describe("reducer", reducerTest(reducer)(function () {
+  this.snapshotAction(setA("other a"));
+  this.snapshotActionSequence(setB({ c: true }), setA("some other"));
+}));

test/reducer.ts

@@ -0,0 +1,30 @@
+import { Dispatch } from "redux";
+
+export interface State {
+  a: string;
+  b?: {
+    c: boolean;
+  };
+  d: number;
+}
+
+const DEFAULT_STATE = {
+  a: "a",
+  d: 0
+}
+
+type Action = { type: "SET_A", payload: State["a"] } | { type: "SET_B", payload: State["b"] } | { type: "SET_D", payload: State["d"] };
+
+export default function reducer(state: State = DEFAULT_STATE, action: Action): State {
+  switch (action.type) {
+    case "SET_A":
+      return { ...state, a: action.payload };
+    case "SET_B":
+      return { ...state, b: action.payload };
+    case "SET_D":
+      return { ...state, d: action.payload };
+  }
+}
+
+export const setA = (a: State["a"]) => ({ type: "SET_A", payload: a });
+export const setB = (b: State["b"]) => ({ type: "SET_B", payload: b });