Add apollo server

Author: mts

packages/server/src/datasources/station.js

@@ -0,0 +1,33 @@
+const { RESTDataSource } = require('apollo-datasource-rest');
+const fetch = require("node-fetch");
+const { stations } = require('./stations.json');
+
+class StationAPI extends RESTDataSource {
+  async getAllStations() {
+    return stations && stations.length ? stations.map(l => this.stationReducer(l)) : []
+  }
+
+  stationReducer(station) {
+    return {
+      id: station.id,
+      lat: station.lat,
+      lng: station.lng,
+      text: station.text,
+      isFocussed: station.isFocussed,
+      isSelected: station.isSelected
+    }
+  }
+
+  async getStationById({ stationId }) {
+    const res = await this.get('stations', { id: stationId })
+    return this.stationReducer(res[0])
+  }
+
+  getStationsByIds({ stationIds }) {
+    return Promise.all(
+      stationIds.map(stationId => this.getStationById({ stationId })),
+    )
+  }
+}
+
+module.exports = StationAPI

packages/server/src/datasources/stations.json

@@ -0,0 +1,10 @@
+{
+  "stations": [
+    { "id": "1", "lat": 52.380528, "lng": 4.900263, "text": "station 1", "isFocussed": true, "isSelected": true },
+    { "id": "2", "lat": 52.378851, "lng": 4.901465, "text": "station 2", "isFocussed": false, "isSelected": false },
+    { "id": "3", "lat": 52.374502, "lng": 4.889878, "text": "station 3", "isFocussed": false, "isSelected": false },
+    { "id": "4", "lat": 52.373244, "lng": 4.890908, "text": "station 4", "isFocussed": false, "isSelected": false },
+    { "id": "5", "lat": 52.368109, "lng": 4.889105, "text": "station 5", "isFocussed": false, "isSelected": false },
+    { "id": "6", "lat": 52.369000, "lng": 4.905671, "text": "station 6", "isFocussed": false, "isSelected": false }
+  ]
+}

packages/server/src/index.js

@@ -1,23 +1,16 @@
-/* eslint no-console: 0 */
-import 'dotenv/config'
-import cors from 'cors'
-import bodyParser from 'body-parser'
-import express from 'express'
+const { ApolloServer } = require('apollo-server');
+const typeDefs = require('./schema');
+const StationAPI = require('./datasources/station');
+const resolvers = require('./resolvers');
 
-const app = express()
+const server = new ApolloServer({
+  typeDefs,
+  resolvers,
+  dataSources: () => ({
+    stationAPI: new StationAPI(),
+  })
+});
 
-app.use(cors())
-
-app.use(bodyParser.urlencoded({ extended: true }))
-
-app.use(bodyParser.json())
-
-app.get('/', (req, res) => {
-  res.send({ 'test': '123' })
-})
-
-const port = process.env.PORT || 3000
-
-app.listen(port, () =>
-  console.log(`Streams Server listening on port ${port}!`),
-)
+server.listen().then(({ url }) => {
+    console.log(`Server ready at ${url}`);
+});

packages/server/src/resolvers.js

@@ -0,0 +1,25 @@
+const { paginateResults } = require('./utils');
+
+module.exports = {
+  Query: {
+    stations: async (_, { pageSize = 20, after }, { dataSources }) => {
+      const allStations = await dataSources.stationAPI.getAllStations()
+      allStations.reverse()
+
+      const stations = paginateResults({
+        after,
+        pageSize,
+        results: allStations,
+      })
+
+      return {
+        stations,
+        cursor: stations.length ? stations[stations.length - 1].cursor : null,
+        hasMore: stations.length
+          ? stations[stations.length - 1].cursor !==
+            allStations[allStations.length - 1].cursor
+          : false,
+      }
+    }
+  }
+}

packages/server/src/schema.js

@@ -0,0 +1,27 @@
+const { gql } = require('apollo-server');
+
+const typeDefs = gql`
+  type Query {
+    stations(
+      pageSize: Int
+      after: String
+    ): StationConnection!
+    station(id: String!): Station
+  }
+
+  type StationConnection {
+    cursor: String!
+    hasMore: Boolean!
+    stations: [Station]!
+  }
+
+  type Station {
+    id: String!
+    lat: Float!
+    lng: Float!
+    text: String!
+    isFocussed: Boolean!
+    isSelected: Boolean!
+  }
+`
+module.exports = typeDefs

packages/server/src/utils.js

@@ -0,0 +1,26 @@
+module.exports.paginateResults = ({
+  after: cursor,
+  pageSize = 20,
+  results,
+  getCursor = () => null,
+}) => {
+  if (pageSize < 1) return []
+
+  if (!cursor) return results.slice(0, pageSize)
+  const cursorIndex = results.findIndex(item => {
+    let itemCursor = item.cursor ? item.cursor : getCursor(item)
+
+    return itemCursor ? cursor === itemCursor : false
+  })
+
+  return cursorIndex >= 0
+    ? cursorIndex === results.length - 1
+      ? []
+      : results.slice(
+          cursorIndex + 1,
+          Math.min(results.length, cursorIndex + 1 + pageSize),
+        )
+    : results.slice(0, pageSize)
+
+  results.slice(cursorIndex >= 0 ? cursorIndex + 1 : 0, cursorIndex >= 0)
+}