feat(query): add metroStations query

It gets the stations data (name, lines, etc) from the tmb website

.eslintrc

@@ -0,0 +1,21 @@
+{
+    "parser": "@typescript-eslint/parser",
+    "extends": [
+      "plugin:@typescript-eslint/eslint-recommended",
+      "plugin:@typescript-eslint/recommended",
+      "plugin:prettier/recommended"
+    ],
+    "plugins": ["node", "@typescript-eslint", "prettier"],
+    "env": {
+      "es6": true,
+      "jest": true,
+      "node": true
+    },
+    "settings": {
+      "import/resolver": {
+        "node": {
+          "extensions": [".js", ".ts"]
+        }
+      }
+    }
+}  

package.json

@@ -21,6 +21,7 @@
     "@graphql-codegen/schema-ast": "^1.17.8",
     "@graphql-codegen/typescript": "^1.17.10",
     "@types/webpack-env": "^1.15.3",
+    "@types/graphql-relay": "^0.6.0",
     "@typescript-eslint/eslint-plugin": "^4.4.0",
     "@typescript-eslint/parser": "^4.4.0",
     "clean-webpack-plugin": "^3.0.0",
@@ -39,7 +40,8 @@
   },
   "dependencies": {
     "apollo-server": "^2.18.2",
-    "graphql": "^15.3.0"
+    "graphql": "^15.3.0",
+    "graphql-relay": "^0.6.0"
   },
   "husky": {
     "hooks": {

schema.graphql

@@ -4,11 +4,71 @@ schema {
 
 """Root Query"""
 type RootQuery {
-  message: Message
+  metroStations(after: String, first: Int, before: String, last: Int): MetroStationsQueryResponse
 }
 
-"""Just a message"""
-type Message {
+union MetroStationsQueryResponse = Error | MetroStationConnection
+
+"""Generic Error"""
+type Error {
+  """HTTP Status Code of the Error"""
+  code: Int
+
+  """Error Description"""
   message: String
-  description: String
+}
+
+"""A connection to a list of items."""
+type MetroStationConnection {
+  """Information to aid in pagination."""
+  pageInfo: PageInfo!
+
+  """A list of edges."""
+  edges: [MetroStationEdge]
+}
+
+"""Information about pagination in a connection."""
+type PageInfo {
+  """When paginating forwards, are there more items?"""
+  hasNextPage: Boolean!
+
+  """When paginating backwards, are there more items?"""
+  hasPreviousPage: Boolean!
+
+  """When paginating backwards, the cursor to continue."""
+  startCursor: String
+
+  """When paginating forwards, the cursor to continue."""
+  endCursor: String
+}
+
+"""An edge in a connection."""
+type MetroStationEdge {
+  """The item at the end of the edge"""
+  node: MetroStation
+
+  """A cursor for use in pagination"""
+  cursor: String!
+}
+
+"""Metro station information"""
+type MetroStation {
+  """Unique ID of the station"""
+  id: ID
+
+  """Name of the station"""
+  name: String
+
+  """Location coordinates of the station"""
+  location: Coordinates
+
+  """Lines the station belongs to e.g. L1, L2"""
+  lines: [String]
+}
+
+"""Coordinates (Latitude, Longitude, Altitude), of a given station/stop"""
+type Coordinates {
+  latitude: Float
+  longitude: Float
+  altitude: Float
 }

src/RootQuery.ts

@@ -1,11 +1,11 @@
 import { GraphQLObjectType } from "graphql";
 
-import message from "./queries/MessageQuery";
+import metroStations from "./queries/MetroStationsQuery";
 
 export default new GraphQLObjectType({
   name: "RootQuery",
   description: "Root Query",
   fields: {
-    message,
+    metroStations
   },
 });

src/index.ts

@@ -14,5 +14,5 @@ server.listen(process.env.PORT || 4000).then(({ url }) => {
 
 if (module.hot) {
   module.hot.accept();
-  module.hot.dispose(() => console.log("Module disposed. "));
+  module.hot.dispose(() => console.log("Module disposed."));
 }

src/queries/MetroStationsQuery.ts

@@ -0,0 +1,41 @@
+import MetroStation from "../types/outputs/MetroStation";
+import Error from "../types/outputs/Error";
+import { GraphQLUnionType } from 'graphql';
+import {
+  connectionArgs,
+  connectionDefinitions,
+  connectionFromArray
+} from 'graphql-relay';
+import type { 
+  MetroStationsQueryResponse as MetroStationsQueryResponseType, 
+  MetroStationConnection as MetroStationConnectionType 
+} from "../types";
+
+const { connectionType: MetroStationConnection } = connectionDefinitions({
+  nodeType: MetroStation,
+});
+
+//MetroStationQuery response as a union of an error or a connection of MetroLine
+const MetroStationsQueryResponse = new GraphQLUnionType({
+  name: 'MetroStationsQueryResponse',
+  types: [Error, MetroStationConnection],
+  resolveType(value) {
+    return value.code !== undefined ? Error : MetroStationConnection;
+  },
+});
+
+export default {
+  type: MetroStationsQueryResponse,
+  args: connectionArgs,
+  resolve: (_, args): MetroStationsQueryResponseType => {
+    return connectionFromArray([{
+      id: '43943949', 
+      lines: ['L1'], 
+      name: 'Clot', 
+      location: {
+        latitude: 2.05, 
+        longitude: 232.4,
+      }
+    }], args) as MetroStationConnectionType;
+  }
+};

src/types.d.ts

@@ -12,12 +12,77 @@ export type Scalars = {
 /** Root Query */
 export type RootQuery = {
   __typename?: 'RootQuery';
-  message?: Maybe<Message>;
+  metroStations?: Maybe<MetroStationsQueryResponse>;
 };
 
-/** Just a message */
-export type Message = {
-  __typename?: 'Message';
+
+/** Root Query */
+export type RootQueryMetroStationsArgs = {
+  after?: Maybe<Scalars['String']>;
+  first?: Maybe<Scalars['Int']>;
+  before?: Maybe<Scalars['String']>;
+  last?: Maybe<Scalars['Int']>;
+};
+
+export type MetroStationsQueryResponse = Error | MetroStationConnection;
+
+/** Generic Error */
+export type Error = {
+  __typename?: 'Error';
+  /** HTTP Status Code of the Error */
+  code?: Maybe<Scalars['Int']>;
+  /** Error Description */
   message?: Maybe<Scalars['String']>;
-  description?: Maybe<Scalars['String']>;
+};
+
+/** A connection to a list of items. */
+export type MetroStationConnection = {
+  __typename?: 'MetroStationConnection';
+  /** Information to aid in pagination. */
+  pageInfo: PageInfo;
+  /** A list of edges. */
+  edges?: Maybe<Array<Maybe<MetroStationEdge>>>;
+};
+
+/** Information about pagination in a connection. */
+export type PageInfo = {
+  __typename?: 'PageInfo';
+  /** When paginating forwards, are there more items? */
+  hasNextPage: Scalars['Boolean'];
+  /** When paginating backwards, are there more items? */
+  hasPreviousPage: Scalars['Boolean'];
+  /** When paginating backwards, the cursor to continue. */
+  startCursor?: Maybe<Scalars['String']>;
+  /** When paginating forwards, the cursor to continue. */
+  endCursor?: Maybe<Scalars['String']>;
+};
+
+/** An edge in a connection. */
+export type MetroStationEdge = {
+  __typename?: 'MetroStationEdge';
+  /** The item at the end of the edge */
+  node?: Maybe<MetroStation>;
+  /** A cursor for use in pagination */
+  cursor: Scalars['String'];
+};
+
+/** Metro station information */
+export type MetroStation = {
+  __typename?: 'MetroStation';
+  /** Unique ID of the station */
+  id?: Maybe<Scalars['ID']>;
+  /** Name of the station */
+  name?: Maybe<Scalars['String']>;
+  /** Location coordinates of the station */
+  location?: Maybe<Coordinates>;
+  /** Lines the station belongs to e.g. L1, L2 */
+  lines?: Maybe<Array<Maybe<Scalars['String']>>>;
+};
+
+/** Coordinates (Latitude, Longitude, Altitude), of a given station/stop */
+export type Coordinates = {
+  __typename?: 'Coordinates';
+  latitude?: Maybe<Scalars['Float']>;
+  longitude?: Maybe<Scalars['Float']>;
+  altitude?: Maybe<Scalars['Float']>;
 };

src/types/outputs/Coordinates.ts

@@ -0,0 +1,17 @@
+import { GraphQLFloat, GraphQLObjectType } from "graphql";
+
+export default new GraphQLObjectType({
+  name: "Coordinates",
+  description: "Coordinates (Latitude, Longitude, Altitude), of a given station/stop",
+  fields: {
+    latitude: {
+      type: GraphQLFloat,
+    },
+    longitude: {
+      type: GraphQLFloat,
+    },
+    altitude: {
+      type: GraphQLFloat
+    }
+  },
+});

src/types/outputs/Error.ts

@@ -0,0 +1,16 @@
+import { GraphQLObjectType, GraphQLString, GraphQLInt } from "graphql";
+
+export default new GraphQLObjectType({
+  name: "Error",
+  description: "Generic Error",
+  fields: {
+    code: {
+      type: GraphQLInt,
+      description: "HTTP Status Code of the Error"
+    },
+    message: {
+        type: GraphQLString,
+        description: "Error Description"
+      },
+  },
+});

src/types/outputs/MetroStation.ts

@@ -0,0 +1,25 @@
+import Coordinates from './Coordinates';
+import { GraphQLObjectType, GraphQLID, GraphQLString, GraphQLList } from "graphql";
+
+export default new GraphQLObjectType({
+  name: "MetroStation",
+  description: "Metro station information",
+  fields: {
+    id: {
+        description: "Unique ID of the station",
+        type: GraphQLID
+    },
+    name: {
+        description: "Name of the station",
+        type: GraphQLString
+    },
+    location: {
+        description: "Location coordinates of the station",
+        type: Coordinates
+    },
+    lines: {
+        description: "Lines the station belongs to e.g. L1, L2",
+        type: GraphQLList(GraphQLString)
+    },
+  },
+});

tsconfig.json

@@ -4,7 +4,7 @@
     "module": "esnext", 
     "moduleResolution": "node",   
     "strict": true,
-    "noImplicitAny": true,              
+    "noImplicitAny": false,
     "strictNullChecks": true,           
     "esModuleInterop": true,                 
     "skipLibCheck": true,