9 | A demo REST API to integrate with a Redux Saga shopping cart app.
10 |
11 |
12 |
16 |
17 | |
18 | route
19 | |
20 |
21 | url
22 | |
23 |
24 | about
25 | |
26 |
27 |
28 | |
29 | User
30 | |
31 |
32 |
33 | /user/:id
34 |
35 | |
36 |
37 | Returns data on the given user ID
38 | |
39 |
40 |
41 | |
42 | Cart
43 | |
44 |
45 |
46 | /user/:owner
47 |
48 | |
49 |
50 | Returns all items in user's cart, or an error if no cart exists.
51 | |
52 |
53 |
54 | |
55 | Cart Add Item
56 | |
57 |
58 |
59 | /cart/add/:owner/:itemID
60 |
61 | |
62 |
63 | Adds an item to the specified owner's cart with the specified ID.
64 | |
65 |
66 |
67 | |
68 | Cart Remove Item
69 | |
70 |
71 |
72 | /cart/remove/:owner/:itemID
73 |
74 | |
75 |
76 | Removes one unit of the specified item from the specified owner's cart.
77 | |
78 |
79 |
80 | |
81 | Items
82 | |
83 |
84 |
85 | /items/:ids
86 |
87 | |
88 |
89 | Returns metadata for a collection of comma-separated item IDS.
90 | |
91 |
92 |
93 | |
94 | Prices
95 | |
96 |
97 |
98 | /prices/:symbol/:ids
99 |
100 | |
101 |
102 | Returns the prices of the specified items in the specified symbol
103 | |
104 |
105 |
106 | |
107 | Shipping
108 | |
109 |
110 |
111 | /shipping/:ids
112 |
113 | |
114 |
115 | Calculates the shipping costs for a block of item IDS.
116 | |
117 |
118 |
119 | |
120 | Tax
121 | |
122 |
123 |
124 | /tax/:symbol
125 |
126 | |
127 |
128 | Returns the tax rate for the given currency or an error if one can't be found.
129 | |
130 |
131 |
132 | |
133 | Checkout (TBC)
134 | |
135 |
136 | /checkout/:owner
137 | |
138 |
139 | Purchases all the items in the cart, or purchases none of the items in the cart if any errors occur.
140 | |
141 |
142 |
143 | |
144 | Card (Validate)
145 | |
146 |
147 |
148 | /card/validate/:owner
149 |
150 | |
151 |
152 | Validates the owner's credit card - always returns {validated:true}
153 | |
154 |
155 |
156 | |
157 | Cart (Validate)
158 | |
159 |
160 |
161 | /cart/validate/:owner
162 |
163 | |
164 |
165 | Validates the cart - returns {validated:true} if all cart items are in stock
166 | |
167 |
168 |
169 | |
170 | Card (charge)
171 | |
172 |
173 |
174 | /cart/charge/:owner
175 |
176 | |
177 |
178 | Charges the user and purchases all items. Returns { success: true } if sufficient funds were available.
179 | |
180 |
181 |
182 |
183 |
184 |
185 |
186 |
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/server.js:
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1 | const express = require('express');
2 | const cors = require('cors');
3 | const port = 8081;
4 | const app = new express();
5 | YAML = require('yamljs');
6 |
7 | const serverDelayConstant = 100;
8 | // Simulate a small amount of delay to demonstrate app's async features
9 | app.use((req,res,next)=>{
10 | const delay = (Math.random() * 15 + 5) * serverDelayConstant;
11 | setTimeout(next,delay);
12 | });
13 |
14 | app.use(express.static('public'));
15 |
16 | nativeObject = YAML.load('database.yml',(database)=>{
17 |
18 | const makeCartAdjustmentRoute = (shouldAdd = true) => (req,res)=>{
19 | const { owner, itemID } = req.params;
20 | const cart = database.carts.find(cart=>cart.owner === owner);
21 | if (!cart) {
22 | return res
23 | .status(500)
24 | .json({
25 | error:"No cart found with the specified ID",
26 | owner
27 | })
28 |
29 | }
30 |
31 | const item = database.items.find(item => item.id === itemID);
32 | if (!item) {
33 | return res
34 | .status(500)
35 | .json({
36 | error:"No item found with the specified ID",
37 | itemID
38 | })
39 | }
40 |
41 |
42 | const existingItem = cart.items.find(cartItem=>cartItem.id === itemID);
43 | if (existingItem) {
44 | if (shouldAdd && parseInt(existingItem.quantity) >= parseInt(item.quantityAvailable)) {
45 | return res.status(503)
46 | .json({
47 | error:"An insufficient quantity of items remains.",
48 | itemID,
49 | quantityAvailable:item.quantityAvailable
50 | });
51 | }
52 | existingItem.quantity += (shouldAdd ? 1 : -1);
53 | if (existingItem.quantity === 0) {
54 | cart.items = cart.items.filter(item=>item.id !== itemID);
55 | }
56 | } else {
57 | if (shouldAdd) {
58 | cart.items.push({
59 | quantity:1,
60 | id:itemID
61 | })
62 | } else {
63 | return res.status(500)
64 | .json({
65 | error:"No item with the specified ID exists in the cart to be removed",
66 | owner,
67 | itemID
68 | })
69 | }
70 |
71 | }
72 | res
73 | .status(200)
74 | .send(cart);
75 | }
76 |
77 | app.get("/cart/add/:owner/:itemID",makeCartAdjustmentRoute(true));
78 | app.get("/cart/remove/:owner/:itemID",makeCartAdjustmentRoute(false));
79 |
80 | app.get("/user/:id",(req,res)=>{
81 | const id = req.params.id;
82 | const user = database.users.find(user=>user.id === id);
83 | if (!user) {
84 | return res
85 | .status(500)
86 | .json({
87 | error:"No user with the specified ID",
88 | id
89 | })
90 | } else {
91 | res
92 | .status(200)
93 | .json(user)
94 | }
95 | });
96 |
97 | app.use(["/cart/validate/:owner","/cart/:owner","/card/charge/:owner"],(req,res,next)=>{
98 | const { owner } = req.params;
99 | const cart = database.carts.find(cart=>cart.owner === owner);
100 | if (!cart){
101 | return res
102 | .status(404)
103 | .json({error:"No cart with the specified owner",owner});
104 | }
105 | else {
106 | req.cart = cart;
107 | next();
108 | }
109 | });
110 |
111 | app.get("/cart/validate/:owner",(req,res)=>{
112 | const { items } = req.cart;
113 | let validated = true;
114 | let error = null;
115 | items.forEach(({id,quantity})=>{
116 | const item = database.items.find(item => item.id === id);
117 | if (item.quantityAvailable < quantity) {
118 | validated = false;
119 | error = "There is an insufficient quantity of " + id;
120 | }
121 | });;
122 | res
123 | .status(200)
124 | .json({validated,error});
125 |
126 | });
127 |
128 |
129 | app.get("/cart/:owner",(req,res)=>{
130 | const cart = req.cart;
131 | res
132 | .status(200)
133 | .json(cart);
134 |
135 | });
136 |
137 | app.use(["/card/validate/:owner","/card/charge/:owner"],(req,res, next)=>{
138 | const {owner} = req.params;
139 | const card = database.cards.find(card=>card.owner === owner);
140 | if (!card){
141 | res.status(500).send({error:`No card is available for user ${owner}`});
142 | }
143 | req.card = card;
144 | next();
145 | });
146 |
147 | app.get("/card/validate/:owner",(req,res)=>{
148 | const {card} = req;
149 | res
150 | .status(200)
151 | .json({validated:true});
152 | });
153 |
154 | app.get("/card/charge/:owner",(req,res)=>{
155 | const {card, cart} = req;
156 | const { owner } = req.params;
157 | const country = database.users.find(user=>user.id === owner).country;
158 | const total = cart.items.reduce((total,{quantity,id})=>{
159 | const item = database.items.find(item=>item.id === id);
160 | const symbol = country === "CAD" ? "cad" : "usd";
161 | const baseValue = item[symbol];
162 | total += baseValue * quantity;
163 | return total;
164 | },0);
165 |
166 | if (card.availableFunds <= total) {
167 | return res
168 | .status(402)
169 | .json({success:false});
170 | }
171 |
172 | card.availableFunds -= total;
173 | res
174 | .status(201)
175 | .send({success:true});
176 |
177 |
178 | });
179 |
180 |
181 |
182 |
183 | app.get("/items/:ids",(req,res)=>{
184 | const ids = req.params.ids.split(',');
185 | const items = ids.map(id=>database.items.find(item=>item.id===id));
186 | if (items.includes(undefined)) {
187 | res
188 | .status(500)
189 | .json({error:"A specified ID had no matching item"});
190 | } else {
191 | res
192 | .status(200)
193 | .json(items);
194 | }
195 | });
196 |
197 | app.get("/prices/:symbol/:ids",(req,res)=>{
198 | const ids = req.params.ids.split(',');
199 | const items = ids.map(id=>database.items.find(item=>item.id===id));
200 | const supportedSymbols = ["CAD","USD"];
201 | const symbol = req.params.symbol;
202 | if (!supportedSymbols.includes(symbol)) {
203 | return res
204 | .status(403)
205 | .json({
206 | error:"The currency symbol provided is inaccurate, see list of supported currencies",
207 | supportedSymbols
208 | })
209 | }
210 |
211 |
212 | if (items.includes(undefined)) {
213 | return res
214 | .status(500)
215 | .json({error:"A specified ID had no matching item"});
216 | } else {
217 | res
218 | .status(200)
219 | .json(items.map(item=>({
220 | id: item.id,
221 | symbol,
222 | price:symbol === "USD" ? item.usd : item.cad
223 | })));
224 | }
225 | });
226 |
227 | app.get('/shipping/:items',(req,res)=>{
228 | const ids = req.params.items.split(',');
229 | let total = 0;
230 | ids.forEach(id=>{
231 | const item = database.items.find(item=>item.id === id);
232 | if (item.weight === 0) {
233 | total += 0;
234 | } else if (item.weight < 0.5) {
235 | total += 3.5;
236 | } else {
237 | total += 8.5;
238 | }
239 | });
240 | res
241 | .status(200)
242 | .json({
243 | total
244 | });
245 | });
246 |
247 | app.get('/tax/:symbol',(req,res)=>{
248 | const { symbol } = req.params;
249 | const taxRate = database.taxRates.find(rate=>rate.symbol === symbol);
250 | if (!taxRate) {
251 | return res
252 | .status(500)
253 | .json({
254 | symbol,
255 | error:"No tax rate info for symbol " + symbol
256 | });
257 | }
258 |
259 | res
260 | .status(200)
261 | .json({
262 | rate:taxRate.rate
263 | })
264 |
265 | });
266 |
267 | app.listen(port,()=>{
268 | console.log(`Redux Saga Cart backend server is listening on ${port}`)
269 | });
270 | });
271 | app.use(cors());
272 |
273 |
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