Use write_source_file / diff_test for Gazelle manifest

gazelle/MODULE.bazel

@@ -4,6 +4,7 @@ module(
     compatibility_level = 1,
 )
 
+bazel_dep(name = "aspect_bazel_lib", version = "2.1.0")
 bazel_dep(name = "rules_python", version = "0.18.0")
 bazel_dep(name = "rules_go", version = "0.41.0", repo_name = "io_bazel_rules_go")
 bazel_dep(name = "gazelle", version = "0.33.0", repo_name = "bazel_gazelle")

gazelle/manifest/BUILD.bazel

@@ -23,7 +23,6 @@ filegroup(
     srcs = glob(["**"]) + [
         "//manifest/generate:distribution",
         "//manifest/hasher:distribution",
-        "//manifest/test:distribution",
     ],
     visibility = ["//:__pkg__"],
 )

gazelle/manifest/defs.bzl

@@ -16,7 +16,8 @@
 for updating and testing the Gazelle manifest file.
 """
 
-load("@io_bazel_rules_go//go:def.bzl", "GoSource", "go_binary", "go_test")
+load("@aspect_bazel_lib//lib:write_source_files.bzl", "write_source_file")
+load("@io_bazel_rules_go//go:def.bzl", "GoSource")
 
 def gazelle_python_manifest(
         name,
@@ -40,8 +41,8 @@ def gazelle_python_manifest(
         pip_deps_repository_name: deprecated - the old pip_install target name.
         modules_mapping: the target for the generated modules_mapping.json file.
         manifest: the target for the Gazelle manifest file.
-        **kwargs: other bazel attributes passed to the target target generated by
-            this macro.
+        **kwargs: other bazel attributes passed to the generate and test targets
+            generated by this macro.
     """
     if pip_deps_repository_name != "":
         # buildifier: disable=print
@@ -55,9 +56,13 @@ def gazelle_python_manifest(
         # This is a temporary check while pip_deps_repository_name exists as deprecated.
         fail("pip_repository_name must be set in //{}:{}".format(native.package_name(), name))
 
+    test_target = "{}.test".format(name)
     update_target = "{}.update".format(name)
     update_target_label = "//{}:{}".format(native.package_name(), update_target)
 
+    manifest_genrule = manifest.replace(":", "") + ".genrule"
+    generated_manifest = manifest + ".generated"
+    manifest_generator = Label("//manifest/generate:generate")
     manifest_generator_hash = Label("//manifest/generate:generate_lib_sources_hash")
 
     if type(requirements) == "list":
@@ -72,15 +77,15 @@ def gazelle_python_manifest(
 
     update_args = [
         "--manifest-generator-hash",
-        "$(rootpath {})".format(manifest_generator_hash),
+        "$(location {})".format(manifest_generator_hash),
         "--requirements",
-        "$(rootpath {})".format(requirements),
+        "$(location {})".format(requirements),
         "--pip-repository-name",
         pip_repository_name,
         "--modules-mapping",
-        "$(rootpath {})".format(modules_mapping),
+        "$(location {})".format(modules_mapping),
         "--output",
-        "$(rootpath {})".format(manifest),
+        "$(location {})".format(generated_manifest),
         "--update-target",
         update_target_label,
     ]
@@ -103,40 +108,30 @@ def gazelle_python_manifest(
             "false",
         ]
 
-    go_binary(
-        name = update_target,
-        embed = [Label("//manifest/generate:generate_lib")],
-        data = [
+    native.genrule(
+        name = manifest_genrule,
+        outs = [generated_manifest],
+        cmd = "$(location {}) {}".format(manifest_generator, " ".join(update_args)),
+        tools = [manifest_generator],
+        srcs = [
             manifest,
             modules_mapping,
             requirements,
             manifest_generator_hash,
         ],
-        args = update_args,
-        visibility = ["//visibility:private"],
-        tags = ["manual"],
     )
 
-    attrs = {
-        "env": {
-            "_TEST_MANIFEST": "$(rootpath {})".format(manifest),
-            "_TEST_MANIFEST_GENERATOR_HASH": "$(rootpath {})".format(manifest_generator_hash),
-            "_TEST_REQUIREMENTS": "$(rootpath {})".format(requirements),
-        },
-        "size": "small",
-    }
-    go_test(
-        name = "{}.test".format(name),
-        srcs = [Label("//manifest/test:test.go")],
-        data = [
-            manifest,
-            requirements,
-            manifest_generator_hash,
-        ],
-        rundir = ".",
-        deps = [Label("//manifest")],
-        # kwargs could contain test-specific attributes like size or timeout
-        **dict(attrs, **kwargs)
+    write_source_file(
+        name = update_target,
+        in_file = generated_manifest,
+        out_file = manifest,
+        **kwargs
+    )
+
+    # For backward compatibility, add an alias to the write_source_file's diff_test
+    native.test_suite(
+        name = test_target,
+        tests = ["{}_test".format(update_target)],
     )
 
     native.filegroup(

gazelle/manifest/generate/generate.go

@@ -31,12 +31,6 @@ import (
 	"github.com/bazelbuild/rules_python/gazelle/manifest"
 )
 
-func init() {
-	if os.Getenv("BUILD_WORKSPACE_DIRECTORY") == "" {
-		log.Fatalln("ERROR: this program must run under Bazel")
-	}
-}
-
 func main() {
 	var (
 		manifestGeneratorHashPath string
@@ -173,12 +167,7 @@ func writeOutput(
 	manifestGeneratorHashPath string,
 	requirementsPath string,
 ) error {
-	stat, err := os.Stat(outputPath)
-	if err != nil {
-		return fmt.Errorf("failed to write output: %w", err)
-	}
-
-	outputFile, err := os.OpenFile(outputPath, os.O_WRONLY|os.O_TRUNC, stat.Mode())
+	outputFile, err := os.OpenFile(outputPath, os.O_WRONLY|os.O_TRUNC|os.O_CREATE, 0644)
 	if err != nil {
 		return fmt.Errorf("failed to write output: %w", err)
 	}