What files are the longest?
What files are changed the most? (See Gary Burhardt's https://github.com/garybernhardt/dotfiles)
Which file do you like best?
Which is worst?
Mirror URL structure
Consistently cased
Colocating related items
Using Dependency Cruiser to validate and enforce intra-project file dependencies.
TypeScript
Use knip or Ts-prune to find unused code and run via CI to protect (something similar for other types of code like CSS?
Eliminate any - Use type-coverage - to report type coverage
Avoid optional fields
Avoid type assertions via “as” (again, can find via type-coverage)
Use string literals instead of string
Replace string | number with number
Don't use 0 or "" for missing numbers
Force TS VersionPrefer Record over switch
See TypeScript issue for more
URL
Does the URL support deep links for sharing when relevant?
Is data from the URL copied into state?
more here
HTML
disabled
main
General
Cpell
Accessibility
See a11y repo
State
Caching fetch calls
CI
Runs build, test, lint
At least one approval is required
PRs aren’t being rubber stamped
No Lint warnings are allowed
Use Danger to enforce ad-hoc checks list a Changelog entry
ESLint
eslint-disable
Unused imports and vars
No var
Prefer const
Running associated package for each tech
Here's a handy checklist: https://github.com/mgreiler/code-review-checklist
When reviewing a code base, here’s what I search for:
(See my review docs, PRs, package.json’s)
JavaScript
CI
See CI issue Preview deployments
Source control
What files are the longest? What files are changed the most? (See Gary Burhardt's https://github.com/garybernhardt/dotfiles) Which file do you like best? Which is worst?
Devops
https://dora.dev/research/
Clean up
Clean up first Signs a team is out of control
Package manager
Consider pnpm or Bun. Consider Corepack
Code reuse
https://github.com/kucherenko/jscpd - Find copy/pasted code See #5 for more on reusable components
Dependencies
depcheck or Knip (listed under TypeScript too) Check for updates Suggest alternative packages
Deploys
Notifying stale SPA users
Formatting
Prettier, running via editor and enforced via CI
Hooks
Using pre-push instead of pre-commit Hook is fast Hook should be redundant - CI = real safety Avoiding useEffect
APIs
Return camelCased JSON Handle saving stale records and protect from overrwrites
HTTP
Centralized URLs (for reuse in APIs and mocks)
Env
Wrapped, strongly typed, Zod validated env vars
Folders
Mirrors URL structure Colocates related files No barrels. my tweet thread
File structure
Mirror URL structure Consistently cased Colocating related items Using Dependency Cruiser to validate and enforce intra-project file dependencies.
TypeScript
Use knip or Ts-prune to find unused code and run via CI to protect (something similar for other types of code like CSS? Eliminate
any- Use type-coverage - to report type coverage Avoid optional fields Avoid type assertions via “as” (again, can find via type-coverage) Use string literals instead of string Replace string | number with number Don't use 0 or "" for missing numbers Force TS Version Prefer Record over switch See TypeScript issue for moreURL
Does the URL support deep links for sharing when relevant? Is data from the URL copied into state? more here
HTML
disabled main
General
Cpell
Accessibility
See a11y repo
State
Caching fetch calls
CI
Runs build, test, lint At least one approval is required PRs aren’t being rubber stamped No Lint warnings are allowed Use Danger to enforce ad-hoc checks list a Changelog entry
ESLint
eslint-disable Unused imports and vars No var Prefer const Running associated package for each tech
React
index Audit useEffect No needless state
Forms
Validation onBlur Does it reflect latest data if user comes back? (easy mistake to make with react-query as mentioned here) What if you try saving stale data that someone else already changed? Dirty notifcation when leaving