Files or folders added in .gitignore file are avoided by Git while tracking. For a typical React project we add following files or folders in .gitignore.
node_modules
Like any other Node projects, we ignore node_modules/ directory. Including node_modules directory increases the project size to a large extend. Other than the size, it is always good to install the packages from package.json if a new developer is cloning the project.
coverage
When we implement code coverage in our project, all the reports are stored in coverage/ folder. We do not want that to be uploaded to Git server.
DS_Store
Mac OS creates this file in every folder if we open that folder in Finder. DS_Store stands for Desktop Services Store. The file basically stores information about the current folder and other files around it. It does not have any signifance specific to our React project.
Distribution
dist/ is the name of a typical directory used to store distribution files. That is the common naming convention. If your project has another name for output folder, give that name in .gitignore.
IDE Specific
If we are working in Visual Studio Code, it automatically creates a .vscode directory to store the project settings. Other editors like Sublime Text has its own versions of settings file. We can exclude those files or directories from versioning.
Logs
Any logs or directories that contains just log information can be ignored. That folder will keep on getting larger and its totally unnecesary to include it in versioning.
Here is an example .gitignore file.
.idea/
.vscode/
node_modules/
build
.DS_Store
*.tgz
my-app*
template/src/__tests__/__snapshots__/
lerna-debug.log
npm-debug.log*
yarn-debug.log*
yarn-error.log*
/.changelog
.npm/Other informations we might add to .gitignore are changelogs, snapshots or build zip files.
Joby Joseph