add store test and fix store

src/store/index.js

@@ -2,8 +2,12 @@ class Store {
   constructor(reducer, catcher) {
     this.reducer = reducer;
     this.catcher = catcher;
-    this.state = this.reducer(undefined, {});
     this.subscribers = [];
+    try {
+      this.state = this.reducer(undefined, {});
+    } catch (e) {
+      catcher(e);
+    }
   }
 
   dispatch(action, sender) {
@@ -20,6 +24,7 @@ class Store {
         this.catcher(e, sender);
       }
     }
+    return action
   }
 
   getState() {

test/store/index.test.js

@@ -0,0 +1,111 @@
+import { expect } from "chai";
+import { createStore } from '../../src/store';
+
+describe("Store class", () => {
+  const reducer = (state, action) => {
+    if (state == undefined) {
+      return 0;
+    }
+    return state + action;
+  };
+
+  describe("#dispatch", () => {
+    it('transit status by immediate action', () => {
+      let store = createStore(reducer);
+      store.dispatch(10);
+      expect(store.getState()).to.equal(10);
+
+      store.dispatch(-20);
+      expect(store.getState()).to.equal(-10);
+    });
+
+    it('returns next state by immediate action', () => {
+      let store = createStore(reducer);
+      let dispatchedAction = store.dispatch(11);
+      expect(dispatchedAction).to.equal(11);
+    });
+
+    it('transit status by Promise action', () => {
+      let store = createStore(reducer);
+      let p1 = Promise.resolve(10);
+
+      return store.dispatch(p1).then(() => {
+        expect(store.getState()).to.equal(10);
+      }).then(() => {
+        store.dispatch(Promise.resolve(-20));
+      }).then(() => {
+        expect(store.getState()).to.equal(-10);
+      });
+    });
+
+    it('returns next state by promise action', () => {
+      let store = createStore(reducer);
+      let dispatchedAction = store.dispatch(Promise.resolve(11));
+      return dispatchedAction.then((value) => {
+        expect(value).to.equal(11);
+      });
+    });
+  });
+
+  describe("#subscribe", () => {
+    it('invoke callback', (done) => {
+      let store = createStore(reducer);
+      store.subscribe(() => {
+        expect(store.getState()).to.equal(15);
+        done();
+      });
+      store.dispatch(15);
+    });
+
+    it('propagate sender object', (done) => {
+      let store = createStore(reducer);
+      store.subscribe((sender) => {
+        expect(sender).to.equal('sender');
+        done();
+      });
+      store.dispatch(15, 'sender');
+    });
+  })
+
+  describe("catcher", () => {
+    it('catch an error in reducer on initializing by immediate action', (done) => {
+      let store = createStore(() => {
+        throw new Error();
+      }, (e) => {
+        expect(e).to.be.an('error');
+        done();
+      });
+    });
+
+    it('catch an error in reducer on initializing by immediate action', (done) => {
+      let store = createStore((state, action) => {
+        if (state === undefined) return 0;
+        throw new Error();
+      }, (e) => {
+        expect(e).to.be.an('error');
+        done();
+      });
+      store.dispatch(20);
+    });
+
+    it('catch an error in reducer on initializing by promise action', (done) => {
+      let store = createStore((state, action) => {
+        if (state === undefined) return 0;
+        throw new Error();
+      }, (e) => {
+        expect(e).to.be.an('error');
+        done();
+      });
+      store.dispatch(Promise.resolve(20));
+    });
+
+    it('catch an error in promise action', (done) => {
+      let store = createStore((state, action) => 0, (e) => {
+        expect(e).to.be.an('error');
+        done();
+      });
+      store.dispatch(new Promise(() => { throw new Error() }));
+    });
+  })
+});
+