Packages: Introduce @automattic/is-plain-object

[tyxla]

Proposed Changes

This PR introduces a new @automattic/is-plain-object package that is intended to be public, and used both in Calypso and in Gutenberg as a replacement for Lodash's isPlainObject() function.

See WordPress/gutenberg#42471 (comment) for the motivation for this package. Essentially, we're aiming to minimize the creation of new packages as Lodash replacements, but we will still end up having a few of them for the greater good.

Testing Instructions

• Verify all package tests pass: yarn test-packages packages/is-plain-object
• Verify all state tests pass: yarn test-client state
• Verify all checks are green and there are no TS errors/warnings introduced.
• Verify the preferences helper still works (displayed when you roll over the environment name in Calypso on non-prod environments).

Pre-merge Checklist

Complete applicable items on this checklist before merging into trunk. Inapplicable items can be left unchecked.

Both the PR author and reviewer are responsible for ensuring the checklist is completed.

• Have you written new tests for your changes?
• Have you tested the feature in Simple, Atomic, and self-hosted Jetpack sites?
• Have you checked for TypeScript, React or other console errors?
• Are we memoizing when appropriate (for expensive computations)? More info in Our Approach to Data and Memoizing with create-selector and Using memoizing selectors
• Have we sent any new strings for translation ASAP?

[github-actions]

Calypso Live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-37772

Jetpack Cloud live (direct link)

https://calypso.live?image=registry.a8c.com/calypso/app:build-37772&env=jetpack

[matticbot]

Here is how your PR affects size of JS and CSS bundles shipped to the user's browser:

App Entrypoints (~98 bytes added 📈 [gzipped])

Details

name           parsed_size           gzip_size
entry-main          +232 B  (+0.0%)      +97 B  (+0.0%)
entry-login         +232 B  (+0.0%)      +99 B  (+0.0%)
entry-stepper       +228 B  (+0.0%)      +94 B  (+0.0%)

Common code that is always downloaded and parsed every time the app is loaded, no matter which route is used.

Async-loaded Components (~86 bytes added 📈 [gzipped])

Details

name                                       parsed_size           gzip_size
async-load-calypso-lib-preferences-helper       +232 B  (+0.2%)      +86 B  (+0.3%)

React components that are loaded lazily, when a certain part of UI is displayed for the first time.

Legend

What is parsed and gzip size?

Parsed Size: Uncompressed size of the JS and CSS files. This much code needs to be parsed and stored in memory.
Gzip Size: Compressed size of the JS and CSS files. This much data needs to be downloaded over network.

Generated by performance advisor bot at iscalypsofastyet.com.

[matticbot]

This PR modifies the release build for editing-toolkit

To test your changes on WordPress.com, run install-plugin.sh editing-toolkit add/is-plain-object-package on your sandbox.

To deploy your changes after merging, see the documentation: PCYsg-mMA-p2

[flootr]

While this works well for me, what about using an existing package like is-plain-obj?

[tyxla]

That one didn't come in my search for some reason - thanks @flootr. Looking at it, it seems like it's the same functionality we need, and comes with TS bindings, so I'm going to give it a try and close this one for now.

[tyxla]

See #65680 for a variant using is-plain-obj.