add positive phones from add feature to state

src/reducers/stateReducer.js

@@ -4,6 +4,22 @@ const initState = () => {
   }
 }
 
+const addPhones = (phones, phone) => {
+  phone.split('').forEach((graph, index) => {
+    if (!phones[graph]) phones[graph] = {}
+  })
+  return phones;
+}
+
+const addPositiveFeature = (phones, positivePhone, feature) => {
+  let node = {}
+  positivePhone.split('').forEach((graph, index) => {
+    node = index === 0 ? node = phones[graph] : node = node[graph];
+    if (index === positivePhone.split('').length - 1) node.features = {...node.features, [feature]: true}
+  })
+  return phones;
+}
+
 const stateReducer = (state, action) => {
   switch (action.type) {
     case 'INIT': {
@@ -26,7 +42,18 @@ const stateReducer = (state, action) => {
 
     case 'ADD_FEATURE': {
       let newFeature = action.value.feature;
-      return {...state, features:[...state.features, newFeature]}
+      let positivePhones = action.value.positivePhones || [];
+      let negativePhones = action.value.negativePhones || [];
+      
+      let newPhoneObject = [
+        ...positivePhones, ...negativePhones
+      ].reduce((phoneObject, phone) => addPhones(phoneObject, phone), state.phones)
+      
+      if (positivePhones) positivePhones = positivePhones.reduce(
+        (phoneObject, positivePhone) => addPositiveFeature(phoneObject, positivePhone, newFeature)
+        , newPhoneObject);
+
+      return {...state, features:[...state.features, newFeature], phones: newPhoneObject}
     }
 
     default:

src/reducers/stateReducer.phones.test.js

@@ -0,0 +1,28 @@
+import {stateReducer} from './stateReducer';
+
+describe('Phones', () => {
+  const n_phone = {features: {nasal: true}}
+  const state = {
+    features: [
+      'nasal'
+    ],
+    phones: { n: n_phone }
+  };
+
+  
+  it('phones returned unaltered', () => {
+    const action = {type: ''};
+    expect(stateReducer(state, action)).toBe(state);
+  });
+
+  it('feature addition returns new feature list with positive phones updated', () => {
+    const action = {type: 'ADD_FEATURE', value: {feature: 'anterior', positivePhones: ['n']}};
+    expect(stateReducer(state, action)).toEqual(
+      {...state, 
+        features:[...state.features, action.value.feature],
+        phones:{...state.phones, n:{...state.phones.n, features: {...state.phones.n.features, anterior: true}}}
+      }
+      )
+  })
+
+});