file_mode

examples/file_mode

Exercises # gazelle:python_generation_mode file — one rule per source file instead of one rule per directory.

Layout

.
└── calc/
    ├── BUILD.bazel    # # gazelle:python_generation_mode file
    ├── add.py         # → py_library(name = "add")
    ├── helpers.py     # → py_library(name = "helpers")
    ├── mul.py         # → py_library(name = "mul", deps = [":add"])
    └── add_test.py    # → py_test(name = "add_test", deps = [":add", ":helpers", ":mul"])

What this verifies

• The directive is read on the package (not the workspace root), so the switch is local to //calc and other packages keep package-mode behavior.
• Per-file libraries are named after the file basename (add.py → :add, mul.py → :mul).
• A per-file library can depend on a sibling per-file library — mul.py imports from calc.add import add, and the resolver fills in deps = [":add"] via the RuleIndex.
• Test files emit one py_test per file. The test's deps aggregate every sibling library's import set, since file mode keeps the surrounding library's deps reachable from each test target.

Try it

bazel run //:gazelle    # generate / update BUILD files
bazel test //...        # run the per-file tests
bazel run //:gazelle -- update -mode=diff   # idempotency check

The BUILD.bazel here is checked in pre-generated; the diff check should report no changes.