Dart .gitignore template

.dart_tool is where the package tool keeps its resolved package configuration, build caches and generated entrypoints. It contains absolute paths to the package cache in your home directory, so it is meaningless on any other machine, and it is rebuilt by a single pub get. The older .packages file did the same job in a flatter format and is kept in the list for repositories that predate the change.

pubspec.lock is the decision to review. It pins the exact version of every direct and transitive dependency. For an application, that pinning is what makes a build reproducible, so most teams commit it and remove this line. For a package published to a registry, consumers resolve their own versions and the lockfile only describes what your own tests ran against, which is the case this template is written for.

The compiled JavaScript rules cover *.dart.js, *.js_, *.js.deps and *.js.map. These are what the web compiler produces from your Dart sources: the bundle itself, the dependency manifest and the source map. All four are regenerated on every build and none of them are readable enough to review in a diff.

doc/api is the generated API documentation directory. It is derived entirely from doc comments in the source, and committing it means every documentation change lands twice in the diff, once in the comment and once in the rendered HTML. Publishing it belongs to a release step rather than to the repository.

build is the general output directory, matched at any depth. In a workspace with several packages that catches each package's output, which is what you want, though it also means a source directory named build anywhere in the tree would be swallowed.