In this challenge, you will write the logic for THIS WIDGET.
Study its functionality and also inspect the Console, the Network tab and the Elements tab in Chrome Dev Tools:
- There are two versions of the widget with identical functionality: class-based and functional.
- The input box at the bottom of the page expects a valid email address.
- Email validation errors arrive from the server, as you can see in the Network tab, under "Preview".
- The payload sent to the server on form submit can also be seen in the Network tab, under "Payload".
- One valid email in particular,
foo@bar.baz
, results in a "Forbidden" server error❗ - The origin of coordinates of the grid is on its top-left corner.
- Node >= 18.x
- NPM >= 9.x (update NPM executing
npm i -g npm
) - Unix-like shell (Gitbash/bash/zsh)
- Chrome >= 100.x
❗ Other configurations might work but haven't been tested.
- Fork, clone, and
npm install
. You won't need to add any extra libraries. - Launch the project on a development server executing
npm run dev
. - Visit your widget by navigating Chrome to
http://localhost:3000
. - Run tests locally executing
npm test
. The test files arecodegrade_mvp.test.js
andApp.test.js
.
- The application includes an endpoint reachable at
POST http://localhost:9000/api/result
. - You can experiment with this endpoint using an HTTP client like Postman.
- The endpoint expects a payload like
{ "x": 1, "y": 2, "steps": 3, "email": "lady@gaga.com" }
:x
should be an integer between 1 and 3.y
should be an integer between 1 and 3.steps
should be an integer larger than 0.email
should be a valid email address.
- Expect an "Unprocessable Entity" server response if the payload has the wrong shape.
-
Replicate the functionality and DOM shown in the prototype linked at the top of this README.
-
Keep your code inside
frontend/components/AppFunctional.js
. -
The component exposed by
AppFunctional.js
must be a stateful functional component. -
The component in
AppClass.js
is optional but can be tackled if desired. It's not required to pass the sprint. -
The DOM produced by
AppFunctional
must match exactly the DOM in the prototype:- The hierarchy of HTML elements, their ids, class names etc must be the same.
- The current square is marked with a capital B and an "active" class name.
- The submit success and error messages that display on the page come from the API (see Network tab).
- No frontend form validation code is required.
-
The coordinates of each square of the grid are as follows:
(1, 1) (2, 1) (3, 1) (1, 2) (2, 2) (3, 2) (1, 3) (2, 3) (3, 3)
❗ ALL TESTS MUST PASS
- Using
codegrade_mvp.test.js
as inspiration, write 5 tests insidefrontend/components/App.test.js
:- From inside the test file, import
AppFunctional.js
. - Test that the visible texts in headings, buttons, links... render on the screen.
- Test that typing on the input results in its value changing to the entered text.
- From inside the test file, import
-
Inside
AppClass.js
andAppFunctional
you will find some suggested states and helper functions. Feel free not to use them. -
You don't need a complicated structure to track the state of the grid, because we aren't storing any information in the cells.
-
Imagine that the grid were simply a one-dimension array broken --only visually-- into three rows.
-
The only component state you need in order to drive the grid is an integer from 0 to 8: the index the "B" is at.
-
Other pieces of information, like coordinates, can be derived from that index, and don't need a state of their own.
-
If you want to make life more complicated (or interesting) for yourself, other structures can be used to store the state of the grid:
// A plain array can be used to represent a grid. // But our App component needn't track the whole array, only the index where the "B" is. [null, null, null, null, "B", null, null, null, null] // 2D arrays or matrices can be used to represent a grid, but this is not recommended in this project: [[null, null, null], [null, "B", null], [null, null, null]] // A string also could work, but strings in JS are immutable making this approach inconvenient: "xxxxBxxxx"
-
"Product" works hard designing the messages: we must reproduce them faithfully, down to the last comma.
-
❗ Remember only the functional version is required; the class-based one is recommended but optional.