Add BankAccount.parse static method

* Add BankAccount.matchDigit private static method

Author: dkubb

spec/bank_account_spec.js

@@ -102,6 +102,109 @@ describe('BankAccount', () => {
     })
   })
 
+  describe('.parse', () => {
+    const testCases = [
+      [
+        '000000000',
+        [
+          ' _  _  _  _  _  _  _  _  _ ',
+          '| || || || || || || || || |',
+          '|_||_||_||_||_||_||_||_||_|'
+        ]
+      ],
+      [
+        '111111111',
+        [
+          '                           ',
+          '  |  |  |  |  |  |  |  |  |',
+          '  |  |  |  |  |  |  |  |  |'
+        ]
+      ],
+      [
+        '222222222',
+        [
+          ' _  _  _  _  _  _  _  _  _ ',
+          ' _| _| _| _| _| _| _| _| _|',
+          '|_ |_ |_ |_ |_ |_ |_ |_ |_ '
+        ]
+      ],
+      [
+        '333333333',
+        [
+          ' _  _  _  _  _  _  _  _  _ ',
+          ' _| _| _| _| _| _| _| _| _|',
+          ' _| _| _| _| _| _| _| _| _|'
+        ]
+      ],
+      [
+        '444444444',
+        [
+          '                           ',
+          '|_||_||_||_||_||_||_||_||_|',
+          '  |  |  |  |  |  |  |  |  |'
+        ]
+      ],
+      [
+        '555555555',
+        [
+          ' _  _  _  _  _  _  _  _  _ ',
+          '|_ |_ |_ |_ |_ |_ |_ |_ |_ ',
+          ' _| _| _| _| _| _| _| _| _|'
+        ]
+      ],
+      [
+        '666666666',
+        [
+          ' _  _  _  _  _  _  _  _  _ ',
+          '|_ |_ |_ |_ |_ |_ |_ |_ |_ ',
+          '|_||_||_||_||_||_||_||_||_|'
+        ]
+      ],
+      [
+        '777777777',
+        [
+          ' _  _  _  _  _  _  _  _  _ ',
+          '  |  |  |  |  |  |  |  |  |',
+          '  |  |  |  |  |  |  |  |  |'
+        ]
+      ],
+      [
+        '888888888',
+        [
+          ' _  _  _  _  _  _  _  _  _ ',
+          '|_||_||_||_||_||_||_||_||_|',
+          '|_||_||_||_||_||_||_||_||_|'
+        ]
+      ],
+      [
+        '999999999',
+        [
+          ' _  _  _  _  _  _  _  _  _ ',
+          '|_||_||_||_||_||_||_||_||_|',
+          ' _| _| _| _| _| _| _| _| _|'
+        ]
+      ],
+      [
+        '123456789',
+        [
+          '    _  _     _  _  _  _  _ ',
+          '  | _| _||_||_ |_   ||_||_|',
+          '  ||_  _|  | _||_|  ||_| _|'
+        ]
+      ]
+    ]
+
+    testCases.forEach(([parsed, text]) => {
+      describe(`when text is ${parsed}`, () => {
+        const bankAccount = BankAccount.parse(text.join('\n'))
+
+        it('parses the expected bank account', () => {
+          expect(bankAccount.format()).toBe(parsed)
+        })
+      })
+    })
+  })
+
   describe('constructor', () => {
     const number      = '345882865'
     const digits      = ''

src/bank_account.js

@@ -47,6 +47,29 @@ class BankAccount {
       .join('\n')
   }
 
+  /* Parse the text into a Bank Account
+   *
+   * @param {string} text
+   *
+   * @returns {BankAccount}
+   */
+  static parse(text) {
+    const digits = this.split(text)
+    const number = digits.map(digit => this.matchDigit(digit))
+    return new this(number, digits)
+  }
+
+  /* Match the digit exactly or return ? for unknown digits
+   *
+   * @param {string}
+   *
+   * @returns {string}
+   * @private
+   */
+  static matchDigit(digit) {
+    return this.DIGITS.indexOf(digit)
+  }
+
   /* Initialize the Bank Account
    *
    * @param {(string|string[])} number