Fix empty package() calls appearing in non-BUILD files

[fmeum]

Caused by 9c3c1fc, but only relevant if users use the pseudo-target __pkg__ with non-BUILD files as recommended for file-level operations.

Work towards #1149
Work towards bazelbuild/bazel#17908

[fmeum]

@laurentlb

Edit: Noticed that per-file commands always skip per-target processing.

[Wyverald]

is there precedent for editing other non-BUILD files? I find the syntax //MODULE.bazel:__pkg__ very unappealing. I'm guessing that //:MODULE.bazel is off the table since it would try to edit the MODULE.bazel target in the BUILD file?

[fmeum]

//MODULE.bazel:all also works and is what I am currently using. Maybe we could make //MODULE.bazel work? It could also be referring to a bazel_dep(name = "MODULE.bazel") though.

[Wyverald]

Maybe we could make //MODULE.bazel work? It could also be referring to a bazel_dep(name = "MODULE.bazel") though.

Did you maybe mean java_library(name = "MODULE.bazel") or something? I didn't know that each individual bazel_dep could be referred to.

[fmeum]

Did you maybe mean java_library(name = "MODULE.bazel") or something? I didn't know that each individual bazel_dep could be referred to.

From the point of view of buildozer, all calls are rules and all rules are the same. As long as your tags have a name attribute, you can even operate on them. We are using this to emit migration commands in Gazelle that look like this:

new go_deps.gazelle_override gopkg.in/yaml.v3|//MODULE.bazel:all
add directives gazelle:go_naming_convention\ go_default_library|//MODULE.bazel:gopkg.in/yaml.v3
rename name path|//MODULE.bazel:gopkg.in/yaml.v3
remove build_naming_convention|//MODULE.bazel:%go_deps.module
remove build_file_proto_mode|//MODULE.bazel:%go_deps.module

But having anything in MODULE.bazel with name = "MODULE.bazel" would still be very weird.

[Wyverald]

Ah I see. I guess my main gripe is that //MODULE.bazel:foo changes the foo "target" in the file /MODULE.bazel, instead of the foo target in the file /MODULE.bazel/BUILD.

I think I'd prefer a special syntax, something like //:__module__, for the MODULE.bazel file. That means you'd need difference syntax to operate on the stuff in there, but we're already kind of doing that (with use_repo_add, for example).

[fmeum]

@vladmos Could you take a look at this fix? I would submit a separate PR that proposes special syntax to identify the MODULE.bazel file.