Jest test has many

[dulerong]

Pull request type

Please check the type of change your PR introduces:

• Bugfix
• Feature
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no api changes)
• Build related changes
• Documentation content changes
• Other (please describe): test

What is the current behaviour?

Issue Number(s): N/A

What is the new behaviour?

• add tests for has_many.js

Other information

N/A

[dulerong]

@ilunglee
Hey, this time I squashed all my commits before pushing, could you please take a look and let me know what you think?

Thanks.

[ilunglee]

Hey @dulerong, thanks for the great work! Please see my comments.

Commit message

When squashing your commits, please ensure you clean up the commit message. For example, I recommend changing the commit message for 9bfc4c8 to:

commit 9bfc4c8e8ea7b54cc79a3c5c2d208fcc24e98d8f
Author: dulerong <codeydu@hotmail.com>
Date:   Tue Oct 12 12:22:48 2021 +0900
    test: add tests for has_many.js

Please see CONTRIBUTING.md for more information.

HTML templates for Jest testings

I'm wondering if it would make sense for us to use jsdom and load an example page (i.e., has_many.html) for jest testings.

document.body.innerHTML = fs.readFileSync("./fixtures/has_many.html");

It will be easier to maintain and much clearer to read this way, and we don't need to create the elements manually. See the following links for more information:

• https://freecontent.manning.com/testing-with-node-jest-and-jsdom
• https://jestjs.io/docs/tutorial-jquery

---

__tests__ folder structure

Also, not related to this PR, I'm wondering if we should move the __tests__ folder from app/javascript/adminterface/lib/__tests__ to app/javascript/adminterface/__tests__ folder to represent all the JavaScript files and move the files to their respective folder paths (e.g., __tests__/has_many.spec.js -> __tests__/lib/has_many.spec.js).

What do you think? Thanks!