You should provide your own project, not the example URL.

You can POST /api/solve with form data containing puzzle which will be a string containing a combination of numbers (1-9) and periods . to represent empty spaces. The returned object will contain a solution property with the solved puzzle.

If the object submitted to /api/solve is missing puzzle, the returned value will be { error: 'Required field missing' }

If the puzzle submitted to /api/solve contains values which are not numbers or periods, the returned value will be { error: 'Invalid characters in puzzle' }

If the puzzle submitted to /api/solve is greater or less than 81 characters, the returned value will be { error: 'Expected puzzle to be 81 characters long' }

If the puzzle submitted to /api/solve is invalid or cannot be solved, the returned value will be { error: 'Puzzle cannot be solved' }

You can POST to /api/check an object containing puzzle, coordinate, and value where the coordinate is the letter A-I indicating the row, followed by a number 1-9 indicating the column, and value is a number from 1-9.

The return value from the POST to /api/check will be an object containing a valid property, which is true if the number may be placed at the provided coordinate and false if the number may not. If false, the returned object will also contain a conflict property which is an array containing the strings "row", "column", and/or "region" depending on which makes the placement invalid.

If value submitted to /api/check is already placed in puzzle on that coordinate, the returned value will be an object containing a valid property with true if value is not conflicting.

If the puzzle submitted to /api/check contains values which are not numbers or periods, the returned value will be { error: 'Invalid characters in puzzle' }

If the puzzle submitted to /api/check is greater or less than 81 characters, the returned value will be { error: 'Expected puzzle to be 81 characters long' }

If the object submitted to /api/check is missing puzzle, coordinate or value, the returned value will be { error: Required field(s) missing }

If the coordinate submitted to api/check does not point to an existing grid cell, the returned value will be { error: 'Invalid coordinate'}

If the value submitted to /api/check is not a number between 1 and 9, the returned values will be { error: 'Invalid value' }

All 12 unit tests are complete and passing. See /tests/1_unit-tests.js for the expected behavior you should write tests for.

All 14 functional tests are complete and passing. See /tests/2_functional-tests.js for the functionality you should write tests for.