Add exports-files-discouraged buildifier lint check - #1494
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Discourage exports_files() as a package encapsulation violation, require scoped visibility and justification comments when it is used, and suggest exposing files via rules such as filegroup instead.
alexeagle
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Aug 27, 2026
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| checkFindings(t, "exports-files-discouraged", ` |
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I think in this case, the comment and visibility should be enough that buildifier exits zero
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| func isPackageOrPackageGroupVisibility(label string) bool { |
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the root package would have to use visibility = //:__subpackages__ - that's probably okay.
Alternatively maybe this rule should not evaluate the root BUILD file since it's common that linters and other repo-wide tooling need their config files in the root?
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Summary
exports_filesis a design smell: it leaks an InputArtifact to be in the srcs of an unrelated Bazel package. This breaks the principle of locality that allows BUILD files to be maintained in isolation.With agents writing more BUILD files I've noticed this pattern increasingly used, when the right answer is to move the rule that needs to consume the source file.
Detail
exports-files-discouragedthat flagsexports_files()as a package encapsulation violation ("feature envy").exports_files()is present, the check also warns if visibility is missing or not scoped to a package (:__pkg__/:__subpackages__) orpackage_group, and if there is no comment explaining why encapsulation is being violated.filegroup) so the owning package can govern access and later swap the label for a generated artifact.Test plan
bazel test //warn:warn_test --test_filter=TestExportsFilesDiscouragedbazel test //warn/docs:docs_test# buildifier: disable=exports-files-discouragedsuppresses all findings