Buildozer Commands Generator

Tool to generate buildozer commands for a given rule and source file or directory.

The generator can create rules for the following and can be extended to provide more

sass_library
sass_binary
ng_module
ts_library

The generator is somewhat flexible in the source structure, but does make a number of assumptions in certain cases. It will try and 'best guess' labels from other packages. It's currently not expected to generate a 100% correct and working build file, but will (in most cases) generate a ~80-90% best effort and reduce the boilerplate needed.

Running the generator

The generator can be run from source via bazel:

bazel run //src:bin -- ts examples/ --base_dir=/usr/workspaces/project

To generate BUILD files using bzlgen from source with bazel, set --base_dir to the absolute path of the target directory

There are many option other flags that can be set to customize the output of the generator, see --help for more

Mapping rules to load statements

By default, the generator won't load rules into the build file. However this can be changed by setting load_mapping flags This tells the generator where to load a given rule from.

This will load sass_library from @io_bazel_rules_sass//sass:sass.bzl. This allows those with marcos overriding rule definitions to specify the correct load site

--load_mapping=sass_library=@io_bazel_rules_sass//sass:sass.bzl

Mapping sources to labels

Label mappings can be added to either override or augment the mapping between a source file and its label. Labels mappings are always the relative path from the root of the workspace (or in the case of node_modules, simply the module name)

--label_mapping path/to/src/component.ts=//some/other:label

Imports can be ignored by setting the path to a blank label

Bazel Query

The generator has experimental use of bazel query to attempt to resolve source files to labels. This can be useful if BUILD files have already been generated in the repo. Mappings added via the --label_mapping flag will have priority over any query results or best guess label generation.

The --use_bazel_query can be set to opt-in to this behaviour

.bzlgenrc

As bzl-gen has a large number of flags, and can read them from a .bzlgenrc file in the root of the repo when to command is run. As load sites can be customized for all rules, it's recommended that the default load sites are added to the rc file.

Each line should contain one flag, all lines are processed, except those starting with #

# load mappings
--load_mapping=sass_library=@io_bazel_rules_sass//sass:sass.bzl
--load_mapping=sass_binary=@io_bazel_rules_sass//sass:sass.bzl
--load_mapping=ts_library=@npm_bazel_typescript//:defs.bzl
--load_mapping=ng_module=@npm_angular_bazel//:index.bzl

# label mappings
--label_mapping=rxjs/operators=@npm//rxjs

ng_bundle

This repo also contains a ng_module macro that this generator can generate for by passing the type ng_bundle. The macro encapsulates common rules used together when building Angular modules, such as a sass_binary for a style or theme file. The macro can be found in index.bzl

Toxicable / bzlgen