| 8 | 8 | * @param {{users: Object[]}} database |
| 9 | 9 | */ |
| 10 | 10 | constructor(database = { users: [] }) { |
| 11 | | throw new Error('Remove this line and implement the function'); |
| 11 | this.database = database; |
| 12 | 12 | } |
| 13 | 13 | |
| 14 | 14 | /** |
| 15 | 15 | * @param {string} url |
| 16 | * @param {Object} [payload] |
| 16 | 17 | * @return {{users: Object[]}} |
| 17 | 18 | */ |
| 18 | | get(url) { |
| 19 | | throw new Error('Remove this line and implement the function'); |
| 19 | get(url, payload = undefined) { |
| 20 | if (url === '/users') { |
| 21 | let users; |
| 22 | if (payload && payload.users && Array.isArray(payload.users)) { |
| 23 | // Return specific users sorted by name |
| 24 | users = this.getUsersByNames(payload.users); |
| 25 | } else { |
| 26 | // Return all users sorted by name |
| 27 | users = [...this.database.users].sort((a, b) => a.name.localeCompare(b.name)); |
| 28 | } |
| 29 | return { users }; |
| 30 | } |
| 31 | return { users: [] }; |
| 20 | 32 | } |
| 21 | 33 | |
| 22 | 34 | /** |
| 25 | 37 | * @return {{users: Object[]}} |
| 26 | 38 | */ |
| 27 | 39 | post(url, payload = undefined) { |
| 28 | | throw new Error('Remove this line and implement the function'); |
| 40 | if (url === '/add') { |
| 41 | // Edge Case: Missing user field in payload |
| 42 | if (!payload || !payload.user) { |
| 43 | return undefined; |
| 44 | } |
| 45 | |
| 46 | // Edge Case: User already exists |
| 47 | const existingUser = this.database.users.find(user => user.name === payload.user); |
| 48 | if (existingUser) { |
| 49 | return existingUser; |
| 50 | } |
| 51 | |
| 52 | // Edge Case: Invalid user name (empty string) |
| 53 | if (payload.user === '') { |
| 54 | return undefined; |
| 55 | } |
| 56 | |
| 57 | const newUser = { |
| 58 | name: payload.user, |
| 59 | owes: {}, |
| 60 | owed_by: {}, |
| 61 | balance: 0.0 |
| 62 | }; |
| 63 | |
| 64 | this.database.users.push(newUser); |
| 65 | return newUser; |
| 66 | } |
| 67 | |
| 68 | if (url === '/iou') { |
| 69 | // Edge Case: Missing required fields in payload |
| 70 | if (!payload || !payload.lender || !payload.borrower || payload.amount === undefined) { |
| 71 | return undefined; |
| 72 | } |
| 73 | |
| 74 | // Edge Case: Invalid amount (negative or zero) |
| 75 | if (payload.amount <= 0) { |
| 76 | return undefined; |
| 77 | } |
| 78 | |
| 79 | // Edge Case: Lender and borrower are the same person |
| 80 | if (payload.lender === payload.borrower) { |
| 81 | return undefined; |
| 82 | } |
| 83 | |
| 84 | const lender = this.database.users.find(user => user.name === payload.lender); |
| 85 | const borrower = this.database.users.find(user => user.name === payload.borrower); |
| 86 | |
| 87 | // Edge Case: Lender or borrower does not exist |
| 88 | if (!lender || !borrower) { |
| 89 | return undefined; |
| 90 | } |
| 91 | |
| 92 | // Update lender's records |
| 93 | if (!lender.owed_by[payload.borrower]) { |
| 94 | lender.owed_by[payload.borrower] = 0; |
| 95 | } |
| 96 | lender.owed_by[payload.borrower] += payload.amount; |
| 97 | |
| 98 | // Update borrower's records |
| 99 | if (!borrower.owes[payload.lender]) { |
| 100 | borrower.owes[payload.lender] = 0; |
| 101 | } |
| 102 | borrower.owes[payload.lender] += payload.amount; |
| 103 | |
| 104 | // Recalculate balances |
| 105 | let totalOwedBy = 0; |
| 106 | for (const amount of Object.values(lender.owed_by)) { |
| 107 | totalOwedBy += amount; |
| 108 | } |
| 109 | |
| 110 | let totalOwes = 0; |
| 111 | for (const amount of Object.values(lender.owes)) { |
| 112 | totalOwes += amount; |
| 113 | } |
| 114 | |
| 115 | lender.balance = totalOwedBy - totalOwes; |
| 116 | |
| 117 | totalOwedBy = 0; |
| 118 | for (const amount of Object.values(borrower.owed_by)) { |
| 119 | totalOwedBy += amount; |
| 120 | } |
| 121 | |
| 122 | totalOwes = 0; |
| 123 | for (const amount of Object.values(borrower.owes)) { |
| 124 | totalOwes += amount; |
| 125 | } |
| 126 | |
| 127 | borrower.balance = totalOwedBy - totalOwes; |
| 128 | |
| 129 | // Return updated users sorted by name |
| 130 | const users = [lender, borrower].sort((a, b) => a.name.localeCompare(b.name)); |
| 131 | return { users }; |
| 132 | } |
| 133 | |
| 134 | return undefined; |
| 135 | } |
| 136 | |
| 137 | // Helper method to get users by names |
| 138 | getUsersByNames(names) { |
| 139 | return this.database.users.filter(user => names.includes(user.name)) |
| 140 | .sort((a, b) => a.name.localeCompare(b.name)); |
| 29 | 141 | } |
| 30 | 142 | } |
| 143 | |
| 144 | // Handled Edge Cases: |
| 145 | // 1. Missing user field in /add request |
| 146 | // 2. User already exists in /add request |
| 147 | // 3. Invalid user name (empty string) in /add request |
| 148 | // 4. Missing required fields in /iou request |
| 149 | // 5. Invalid amount (negative or zero) in /iou request |
| 150 | // 6. Lender and borrower are the same person in /iou request |
| 151 | // 7. Lender or borrower does not exist in /iou request |