These packages provide utilities for generating Dart code.

build

Defines the interfaces for creating a Builder which is a way of doing codegen that is compatible across build systems (pub, bazel, standalone runner).

For packages doing code generation this should generally be the only package against which there is a public dependency. Packages may have a dev_depenency on one or more of the other packages.

In particular, transformers should only be exposed via a separate package, which has a dependency on build_barback. This allows core packages to not leak the dependency on barback and all of its transitive deps to all consumers.

build_barback

Allows wrapping up a Builder as a Transformer so that it can be run in pub or vice-versa.

build_runner

Provides build and watch utilities to enact builds.

This package should generally be a dev_dependency as it is used to run standalone builds. The only exception would be wrapping the build and watch methods with some other package.

build_test

Stub implementations for classes in Build and some utilities for running instances of builds and checking their outputs.

This package generally only be a dev_dependency as it introduces a dependency on package:test. The exception to that would be if you were creating another testing-only package that wraps this one.

Examples

The e2e_example directory has demonstrations of running a Builder both through pub (see the transformers section of pubspec.yaml) and in place (see the files build.dart and watch.dart). In real situations a project would choose one or the other approach rather than mix both.