fix[gazelle]: handle auto-included __init__.py when generating py_binary targets.

Fixes bazel-contrib#3729

Author: jvolkman

gazelle/python/generate.go

@@ -258,6 +258,15 @@ func (py *Python) GenerateRules(args language.GenerateArgs) language.GenerateRes
 	// Create a validFilesMap of mainModules to validate if python macros have valid srcs.
 	validFilesMap := make(map[string]struct{})
 
+	// Determine whether we have an __init__.py file in this package and whether we'll implicitly include it in srcs.
+	var nonEmptyInit bool
+	var autoIncludeInit bool
+	if cfg.PerFileGeneration() {
+		hasInit, nei := hasLibraryEntrypointFile(args.Dir)
+		nonEmptyInit = nei
+		autoIncludeInit = cfg.PerFileGenerationIncludeInit() && hasInit && nonEmptyInit
+	}
+
 	appendPyLibrary := func(srcs *treeset.Set, pyLibraryTargetName string) {
 		allDeps, mainModules, annotations, err := parser.parse(srcs)
 		for name := range mainModules {
@@ -277,6 +286,10 @@ func (py *Python) GenerateRules(args language.GenerateArgs) language.GenerateRes
 				// that we don't also generate a py_library target for it.
 				if cfg.PerFileGeneration() {
 					srcs.Remove(name)
+					// Also remove the __init__.py that was added earlier.
+					if autoIncludeInit {
+						srcs.Remove(pyLibraryEntrypointFilename)
+					}
 				}
 			}
 
@@ -294,15 +307,20 @@ func (py *Python) GenerateRules(args language.GenerateArgs) language.GenerateRes
 				filenames := treeset.NewWith(godsutils.StringComparator, filename)
 				pyiSrcs, _ := getPyiFilenames(filenames, cfg.GeneratePyiSrcs(), args.Dir)
 
-				pyBinary := newTargetBuilder(pyBinaryKind, pyBinaryTargetName, pythonProjectRoot, args.Rel, pyFileNames, cfg.ResolveSiblingImports()).
+				pyBinaryBuilder := newTargetBuilder(pyBinaryKind, pyBinaryTargetName, pythonProjectRoot, args.Rel, pyFileNames, cfg.ResolveSiblingImports()).
 					addVisibility(visibility).
 					addSrc(filename).
 					addPyiSrcs(pyiSrcs).
 					addModuleDependencies(mainModules[filename]).
 					addResolvedDependencies(annotations.includeDeps).
 					generateImportsAttribute().
-					setAnnotations(*annotations).
-					build()
+					setAnnotations(*annotations)
+
+				if autoIncludeInit {
+					pyBinaryBuilder.addSrc(pyLibraryEntrypointFilename)
+				}
+
+				pyBinary := pyBinaryBuilder.build()
 				result.Gen = append(result.Gen, pyBinary)
 				result.Imports = append(result.Imports, pyBinary.PrivateAttr(config.GazelleImportsKey))
 			}
@@ -357,15 +375,15 @@ 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{}) {
 			pyLibraryTargetName := strings.TrimSuffix(filepath.Base(filename.(string)), ".py")
 			if filename == pyLibraryEntrypointFilename && !nonEmptyInit {
 				return // ignore empty __init__.py.
 			}
 			srcs := treeset.NewWith(godsutils.StringComparator, filename)
-			if cfg.PerFileGenerationIncludeInit() && hasInit && nonEmptyInit {
+			if autoIncludeInit {
 				srcs.Add(pyLibraryEntrypointFilename)
 			}
 			appendPyLibrary(srcs, pyLibraryTargetName)

gazelle/python/testdata/per_file_non_empty_init/BUILD.out

@@ -1,4 +1,4 @@
-load("@rules_python//python:defs.bzl", "py_library")
+load("@rules_python//python:defs.bzl", "py_binary", "py_library")
 
 # gazelle:python_generation_mode file
 # gazelle:python_generation_mode_per_file_include_init true
@@ -18,3 +18,13 @@ py_library(
     ],
     visibility = ["//:__subpackages__"],
 )
+
+py_binary(
+    name = "foobin",
+    srcs = [
+        "__init__.py",
+        "foobin.py",
+    ],
+    visibility = ["//:__subpackages__"],
+    deps = [":foo"],
+)

gazelle/python/testdata/per_file_non_empty_init/README.md

@@ -1,3 +1,3 @@
 # Per-file generation
 
-This test case generates one `py_library` per file, including `__init__.py`.
+This test case generates one `py_library` or `py_binary` per file, including `__init__.py`.

gazelle/python/testdata/per_file_non_empty_init/foo.py

@@ -13,3 +13,4 @@
 # limitations under the License.
 
 # For test purposes only.
+BAR = "baz"

gazelle/python/testdata/per_file_non_empty_init/foobin.py

@@ -0,0 +1,4 @@
+from foo import BAR
+
+if __name__ == "__main__":
+    print(BAR)