Merge pull request #2 from arunoda/add-update

Add an update API to update the multiple entries in the store

README.md

@@ -73,6 +73,19 @@ Get a value by the give key.
 store.get('key');
 ```
 
+### update
+
+Update multiple entries of the store at once. While updating, you could accept the current state of the store as well.
+
+```js
+store.update(function(state) {
+  return {
+    newField: 10,
+    existingField: !Boolean(existingField)
+  };
+});
+```
+
 ### getAll
 
 Get all the key values pairs in the store as a map.

src/index.js

@@ -23,6 +23,18 @@ export default class Podda {
     this.fire(key, value);
   }
 
+  update(fn) {
+    const currentState = this.data.toJS();
+    const newFields = fn(currentState);
+    if (newFields === null || newFields === undefined) {
+      throw new Error('You must provide an object with updated values for Podda.set(fn)');
+    }
+
+    Object.keys(newFields).forEach((key) => {
+      this.set(key, newFields[key]);
+    });
+  }
+
   get(key) {
     const value = this.data.get(key);
     if (value === null || value === undefined) {

src/tests/index.js

@@ -22,6 +22,41 @@ describe('Podda', () => {
       expect(store.get('abc')).to.be.equal('ppc');
     });
 
+    it('should support to update with a function', () => {
+      const store = new Podda({
+        abc: 10,
+        bbc: 20,
+      });
+
+      store.update((state) => {
+        expect(state).to.deep.equal({ abc: 10, bbc: 20 });
+        // this is not going to add to the store.
+        state.someItem = 1000; // eslint-disable-line
+
+        return { bbc: 50, cnn: 100 };
+      });
+
+      expect(store.getAll()).to.deep.equal({
+        abc: 10,
+        bbc: 50,
+        cnn: 100,
+      });
+    });
+
+    it('should throw an error if update function returns nothing', () => {
+      const store = new Podda();
+      const run1 = () => {
+        store.update(() => null);
+      };
+
+      const run2 = () => {
+        store.update(() => {});
+      };
+
+      expect(run1).to.throw(/an object with updated values/);
+      expect(run2).to.throw(/an object with updated values/);
+    });
+
     it('should support getting all the values', () => {
       const store = new Podda();
       store.set('abc', 'kkr');