Add buildifier checks and formatting

.github/workflows/build.yml

@@ -9,6 +9,17 @@ on:
     branches: [master]
 
 jobs:
+  buildifier:
+    name: Buildifier
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v3
+      - name: Run Buildifier checks
+        uses: thompsonja/bazel-buildifier@v0.4.0
+        with:
+          warnings: all
+
   run-tests:
     timeout-minutes: 15
     strategy:

WORKSPACE

@@ -1,4 +1,5 @@
 workspace(name = "io_bazel_rules_dart")
 
 load("//dart/build_rules:repositories.bzl", "dart_repositories")
+
 dart_repositories()

dart/build_rules/core.bzl

@@ -14,33 +14,31 @@
 
 """Dart rules shared across deployment platforms."""
 
-
 load(":internal.bzl", "assert_third_party_licenses", "make_dart_context")
 
-
 def _dart_library_impl(ctx):
-  """Implements the dart_library() rule."""
-  assert_third_party_licenses(ctx)
+    """Implements the dart_library() rule."""
+    assert_third_party_licenses(ctx)
 
-  dart_ctx = make_dart_context(ctx.label,
-                               srcs=ctx.files.srcs,
-                               data=ctx.files.data,
-                               deps=ctx.attr.deps)
-
-  return struct(
-      dart=dart_ctx,
-  )
+    dart_ctx = make_dart_context(
+        ctx.label,
+        srcs = ctx.files.srcs,
+        data = ctx.files.data,
+        deps = ctx.attr.deps,
+    )
 
+    return struct(
+        dart = dart_ctx,
+    )
 
 dart_library_attrs = {
-    "srcs": attr.label_list(allow_files=True, mandatory=True),
-    "data": attr.label_list(allow_files=True),
-    "deps": attr.label_list(providers=["dart"]),
-    "license_files": attr.label_list(allow_files=True)
+    "srcs": attr.label_list(allow_files = True, mandatory = True),
+    "data": attr.label_list(allow_files = True),
+    "deps": attr.label_list(providers = ["dart"]),
+    "license_files": attr.label_list(allow_files = True),
 }
 
-
 dart_library = rule(
-    implementation=_dart_library_impl,
-    attrs=dart_library_attrs,
+    implementation = _dart_library_impl,
+    attrs = dart_library_attrs,
 )