fix(gazelle): __init__.py in per-file targets

CHANGELOG.md

@@ -50,6 +50,9 @@ A brief description of the categories of changes:
 ### Added
 
 * (docs) bzlmod extensions are now documented on rules-python.readthedocs.io
+* (gazelle) `file` generation mode can now also add `__init__.py` to the srcs
+  attribute for every target in the package. This is enabled through a separate
+  directive `python_generation_mode_per_file_include_init`.
 
 [0.XX.0]: https://github.com/bazelbuild/rules_python/releases/tag/0.XX.0
 

gazelle/README.md

@@ -184,6 +184,8 @@ Python-specific directives are as follows:
 | Controls whether the Python import statements should be validated. Can be "true" or "false" | |
 | `# gazelle:python_generation_mode`| `package` |
 | Controls the target generation mode. Can be "file", "package", or "project" | |
+| `# gazelle:python_generation_mode_per_file_include_init`| `package` |
+| Controls whether `__init__.py` files are included as srcs in each generated target when target generation mode is "file". Can be "true", or "false" | |
 | `# gazelle:python_library_naming_convention`| `$package_name$` |
 | Controls the `py_library` naming convention. It interpolates \$package_name\$ with the Bazel package name. E.g. if the Bazel package name is `foo`, setting this to `$package_name$_my_lib` would result in a generated target named `foo_my_lib`. | |
 | `# gazelle:python_binary_naming_convention` | `$package_name$_bin` |

gazelle/python/configure.go

@@ -59,6 +59,7 @@ func (py *Configurer) KnownDirectives() []string {
 		pythonconfig.IgnoreDependenciesDirective,
 		pythonconfig.ValidateImportStatementsDirective,
 		pythonconfig.GenerationMode,
+		pythonconfig.GenerationModePerFileIncludeInit,
 		pythonconfig.LibraryNamingConvention,
 		pythonconfig.BinaryNamingConvention,
 		pythonconfig.TestNamingConvention,
@@ -149,6 +150,12 @@ func (py *Configurer) Configure(c *config.Config, rel string, f *rule.File) {
 					pythonconfig.GenerationMode, d.Value)
 				log.Fatal(err)
 			}
+		case pythonconfig.GenerationModePerFileIncludeInit:
+			v, err := strconv.ParseBool(strings.TrimSpace(d.Value))
+			if err != nil {
+				log.Fatal(err)
+			}
+			config.SetPerFileGenerationIncludeInit(v)
 		case pythonconfig.LibraryNamingConvention:
 			config.SetLibraryNamingConvention(strings.TrimSpace(d.Value))
 		case pythonconfig.BinaryNamingConvention:

gazelle/python/generate.go

@@ -272,18 +272,16 @@ func (py *Python) GenerateRules(args language.GenerateArgs) language.GenerateRes
 		result.Imports = append(result.Imports, pyLibrary.PrivateAttr(config.GazelleImportsKey))
 	}
 	if cfg.PerFileGeneration() {
+		hasInit, nonEmptyInit := hasLibraryEntrypointFile(args.Dir)
 		pyLibraryFilenames.Each(func(index int, filename interface{}) {
-			if filename == pyLibraryEntrypointFilename {
-				stat, err := os.Stat(filepath.Join(args.Dir, filename.(string)))
-				if err != nil {
-					log.Fatalf("ERROR: %v\n", err)
-				}
-				if stat.Size() == 0 {
-					return // ignore empty __init__.py
-				}
+			pyLibraryTargetName := strings.TrimSuffix(filepath.Base(filename.(string)), ".py")
+			if filename == pyLibraryEntrypointFilename && !nonEmptyInit {
+				return // ignore empty __init__.py.
 			}
 			srcs := treeset.NewWith(godsutils.StringComparator, filename)
-			pyLibraryTargetName := strings.TrimSuffix(filepath.Base(filename.(string)), ".py")
+			if cfg.PerFileGenerationIncludeInit() && hasInit && nonEmptyInit {
+				srcs.Add(pyLibraryEntrypointFilename)
+			}
 			appendPyLibrary(srcs, pyLibraryTargetName)
 		})
 	} else if !pyLibraryFilenames.Empty() {
@@ -468,6 +466,19 @@ func hasEntrypointFile(dir string) bool {
 	return false
 }
 
+// hasLibraryEntrypointFile returns if the given directory has the library
+// entrypoint file, and if it is non-empty.
+func hasLibraryEntrypointFile(dir string) (bool, bool) {
+	stat, err := os.Stat(filepath.Join(dir, pyLibraryEntrypointFilename))
+	if os.IsNotExist(err) {
+		return false, false
+	}
+	if err != nil {
+		log.Fatalf("ERROR: %v\n", err)
+	}
+	return true, stat.Size() != 0
+}
+
 // isEntrypointFile returns whether the given path is an entrypoint file. The
 // given path can be absolute or relative.
 func isEntrypointFile(path string) bool {

gazelle/python/resolve.go

@@ -61,11 +61,17 @@ func (py *Resolver) Imports(c *config.Config, r *rule.Rule, f *rule.File) []reso
 	provides := make([]resolve.ImportSpec, 0, len(srcs)+1)
 	for _, src := range srcs {
 		ext := filepath.Ext(src)
-		if ext == ".py" {
-			pythonProjectRoot := cfg.PythonProjectRoot()
-			provide := importSpecFromSrc(pythonProjectRoot, f.Pkg, src)
-			provides = append(provides, provide)
+		if ext != ".py" {
+			continue
 		}
+		if cfg.PerFileGeneration() && len(srcs) > 1 && src == pyLibraryEntrypointFilename {
+			// Do not provide import spec from __init__.py when it is being included as
+			// part of another module.
+			continue
+		}
+		pythonProjectRoot := cfg.PythonProjectRoot()
+		provide := importSpecFromSrc(pythonProjectRoot, f.Pkg, src)
+		provides = append(provides, provide)
 	}
 	if len(provides) == 0 {
 		return nil

gazelle/python/testdata/per_file_non_empty_init/BUILD.in

@@ -1,3 +1,4 @@
 load("@rules_python//python:defs.bzl", "py_library")
 
 # gazelle:python_generation_mode file
+# gazelle:python_generation_mode_per_file_include_init true

gazelle/python/testdata/per_file_non_empty_init/BUILD.out

@@ -1,6 +1,7 @@
 load("@rules_python//python:defs.bzl", "py_library")
 
 # gazelle:python_generation_mode file
+# gazelle:python_generation_mode_per_file_include_init true
 
 py_library(
     name = "__init__",
@@ -11,6 +12,9 @@ py_library(
 
 py_library(
     name = "foo",
-    srcs = ["foo.py"],
+    srcs = [
+        "__init__.py",
+        "foo.py",
+    ],
     visibility = ["//:__subpackages__"],
 )

gazelle/python/testdata/per_file_subdirs/bar/BUILD.in

@@ -0,0 +1 @@
+# gazelle:python_generation_mode_per_file_include_init true

gazelle/python/testdata/per_file_subdirs/bar/BUILD.out

@@ -1,14 +1,28 @@
 load("@rules_python//python:defs.bzl", "py_library", "py_test")
 
+# gazelle:python_generation_mode_per_file_include_init true
+
 py_library(
     name = "__init__",
     srcs = ["__init__.py"],
     visibility = ["//:__subpackages__"],
 )
 
+py_library(
+    name = "bar",
+    srcs = [
+        "__init__.py",
+        "bar.py",
+    ],
+    visibility = ["//:__subpackages__"],
+)
+
 py_library(
     name = "foo",
-    srcs = ["foo.py"],
+    srcs = [
+        "__init__.py",
+        "foo.py",
+    ],
     visibility = ["//:__subpackages__"],
 )
 

gazelle/pythonconfig/pythonconfig.go

@@ -50,6 +50,10 @@ const (
 	// GenerationMode represents the directive that controls the target generation
 	// mode. See below for the GenerationModeType constants.
 	GenerationMode = "python_generation_mode"
+	// GenerationModePerFileIncludeInit represents the directive that augments
+	// the "per_file" GenerationMode by including the package's __init__.py file.
+	// This is a boolean directive.
+	GenerationModePerFileIncludeInit = "python_generation_mode_per_file_include_init"
 	// LibraryNamingConvention represents the directive that controls the
 	// py_library naming convention. It interpolates $package_name$ with the
 	// Bazel package name. E.g. if the Bazel package name is `foo`, setting this
@@ -122,15 +126,16 @@ type Config struct {
 	pythonProjectRoot string
 	gazelleManifest   *manifest.Manifest
 
-	excludedPatterns         *singlylinkedlist.List
-	ignoreFiles              map[string]struct{}
-	ignoreDependencies       map[string]struct{}
-	validateImportStatements bool
-	coarseGrainedGeneration  bool
-	perFileGeneration        bool
-	libraryNamingConvention  string
-	binaryNamingConvention   string
-	testNamingConvention     string
+	excludedPatterns             *singlylinkedlist.List
+	ignoreFiles                  map[string]struct{}
+	ignoreDependencies           map[string]struct{}
+	validateImportStatements     bool
+	coarseGrainedGeneration      bool
+	perFileGeneration            bool
+	perFileGenerationIncludeInit bool
+	libraryNamingConvention      string
+	binaryNamingConvention       string
+	testNamingConvention         string
 }
 
 // New creates a new Config.
@@ -139,18 +144,19 @@ func New(
 	pythonProjectRoot string,
 ) *Config {
 	return &Config{
-		extensionEnabled:         true,
-		repoRoot:                 repoRoot,
-		pythonProjectRoot:        pythonProjectRoot,
-		excludedPatterns:         singlylinkedlist.New(),
-		ignoreFiles:              make(map[string]struct{}),
-		ignoreDependencies:       make(map[string]struct{}),
-		validateImportStatements: true,
-		coarseGrainedGeneration:  false,
-		perFileGeneration:        false,
-		libraryNamingConvention:  packageNameNamingConventionSubstitution,
-		binaryNamingConvention:   fmt.Sprintf("%s_bin", packageNameNamingConventionSubstitution),
-		testNamingConvention:     fmt.Sprintf("%s_test", packageNameNamingConventionSubstitution),
+		extensionEnabled:             true,
+		repoRoot:                     repoRoot,
+		pythonProjectRoot:            pythonProjectRoot,
+		excludedPatterns:             singlylinkedlist.New(),
+		ignoreFiles:                  make(map[string]struct{}),
+		ignoreDependencies:           make(map[string]struct{}),
+		validateImportStatements:     true,
+		coarseGrainedGeneration:      false,
+		perFileGeneration:            false,
+		perFileGenerationIncludeInit: false,
+		libraryNamingConvention:      packageNameNamingConventionSubstitution,
+		binaryNamingConvention:       fmt.Sprintf("%s_bin", packageNameNamingConventionSubstitution),
+		testNamingConvention:         fmt.Sprintf("%s_test", packageNameNamingConventionSubstitution),
 	}
 }
 
@@ -163,19 +169,20 @@ func (c *Config) Parent() *Config {
 // current Config and sets itself as the parent to the child.
 func (c *Config) NewChild() *Config {
 	return &Config{
-		parent:                   c,
-		extensionEnabled:         c.extensionEnabled,
-		repoRoot:                 c.repoRoot,
-		pythonProjectRoot:        c.pythonProjectRoot,
-		excludedPatterns:         c.excludedPatterns,
-		ignoreFiles:              make(map[string]struct{}),
-		ignoreDependencies:       make(map[string]struct{}),
-		validateImportStatements: c.validateImportStatements,
-		coarseGrainedGeneration:  c.coarseGrainedGeneration,
-		perFileGeneration:        c.perFileGeneration,
-		libraryNamingConvention:  c.libraryNamingConvention,
-		binaryNamingConvention:   c.binaryNamingConvention,
-		testNamingConvention:     c.testNamingConvention,
+		parent:                       c,
+		extensionEnabled:             c.extensionEnabled,
+		repoRoot:                     c.repoRoot,
+		pythonProjectRoot:            c.pythonProjectRoot,
+		excludedPatterns:             c.excludedPatterns,
+		ignoreFiles:                  make(map[string]struct{}),
+		ignoreDependencies:           make(map[string]struct{}),
+		validateImportStatements:     c.validateImportStatements,
+		coarseGrainedGeneration:      c.coarseGrainedGeneration,
+		perFileGeneration:            c.perFileGeneration,
+		perFileGenerationIncludeInit: c.perFileGenerationIncludeInit,
+		libraryNamingConvention:      c.libraryNamingConvention,
+		binaryNamingConvention:       c.binaryNamingConvention,
+		testNamingConvention:         c.testNamingConvention,
 	}
 }
 
@@ -344,6 +351,18 @@ func (c *Config) PerFileGeneration() bool {
 	return c.perFileGeneration
 }
 
+// SetPerFileGenerationIncludeInit sets whether py_library targets should
+// include __init__.py files when PerFileGeneration() is true.
+func (c *Config) SetPerFileGenerationIncludeInit(includeInit bool) {
+	c.perFileGenerationIncludeInit = includeInit
+}
+
+// PerFileGenerationIncludeInit returns whether py_library targets should
+// include __init__.py files when PerFileGeneration() is true.
+func (c *Config) PerFileGenerationIncludeInit() bool {
+	return c.perFileGenerationIncludeInit
+}
+
 // SetLibraryNamingConvention sets the py_library target naming convention.
 func (c *Config) SetLibraryNamingConvention(libraryNamingConvention string) {
 	c.libraryNamingConvention = libraryNamingConvention