Add go_bazel_test for nogo

Requires some changes to the `go_bazel_test` setup.

.bazelci/presubmit.yml

@@ -16,6 +16,8 @@ tasks:
       - "//..."
     test_targets:
       - "//..."
+      # Bzlmod tests require Bazel 6+
+      - "-//tests/core/nogo/bzlmod/..."
   ubuntu2004:
     # enable some unflipped incompatible flags on this platform to ensure we don't regress.
     shell_commands:

BUILD.bazel

@@ -169,7 +169,10 @@ filegroup(
     testonly = True,
     srcs = [
         "BUILD.bazel",
+        "MODULE.bazel",
         "WORKSPACE",
+        "go.mod",
+        "go.sum",
         "//extras:all_files",
         "//go:all_files",
         "//proto:all_files",

go/tools/bazel_testing/bazel_testing.go

@@ -75,6 +75,11 @@ type Args struct {
 	// of the default generated WORKSPACE file.
 	WorkspaceSuffix string
 
+	// ModuleFileSuffix is a string that should be appended to the end of a
+	// default generated MODULE.bazel file. If this is empty, no such file is
+	// generated.
+	ModuleFileSuffix string
+
 	// SetUp is a function that is executed inside the context of the testing
 	// workspace. It is executed once and only once before the beginning of
 	// all tests. If SetUp returns a non-nil error, execution is halted and
@@ -384,8 +389,9 @@ func setupWorkspace(args Args, files []string) (dir string, cleanup func() error
 
 	// If there's no WORKSPACE file, create one.
 	workspacePath := filepath.Join(mainDir, "WORKSPACE")
-	if _, err := os.Stat(workspacePath); os.IsNotExist(err) {
-		w, err := os.Create(workspacePath)
+	if _, err = os.Stat(workspacePath); os.IsNotExist(err) {
+		var w *os.File
+		w, err = os.Create(workspacePath)
 		if err != nil {
 			return "", cleanup, err
 		}
@@ -416,6 +422,46 @@ func setupWorkspace(args Args, files []string) (dir string, cleanup func() error
 		}
 	}
 
+	// If a MODULE.bazel file is requested, create one.
+	if args.ModuleFileSuffix != "" {
+		moduleBazelPath := filepath.Join(mainDir, "MODULE.bazel")
+		if _, err = os.Stat(moduleBazelPath); err == nil {
+			return "", cleanup, fmt.Errorf("ModuleFileSuffix set but MODULE.bazel exists")
+		}
+		var w *os.File
+		w, err = os.Create(moduleBazelPath)
+		if err != nil {
+			return "", cleanup, err
+		}
+		defer func() {
+			if cerr := w.Close(); err == nil && cerr != nil {
+				err = cerr
+			}
+		}()
+		rulesGoAbsPath := filepath.Join(execDir, "io_bazel_rules_go")
+		rulesGoPath, err := filepath.Rel(mainDir, rulesGoAbsPath)
+		if err != nil {
+			return "", cleanup, fmt.Errorf("could not find relative path from %q to %q for io_bazel_rules_go", mainDir, rulesGoAbsPath)
+		}
+		rulesGoPath = filepath.ToSlash(rulesGoPath)
+		info := moduleFileTemplateInfo{
+			RulesGoPath: rulesGoPath,
+			Suffix:      args.ModuleFileSuffix,
+		}
+		if err := defaultModuleBazelTpl.Execute(w, info); err != nil {
+			return "", cleanup, err
+		}
+
+		// Enable Bzlmod.
+		bazelrcPath := filepath.Join(mainDir, ".bazelrc")
+		if _, err = os.Stat(bazelrcPath); os.IsNotExist(err) {
+			err = os.WriteFile(bazelrcPath, []byte("common --enable_bzlmod"), 0666)
+			if err != nil {
+				return "", cleanup, err
+			}
+		}
+	}
+
 	return mainDir, cleanup, nil
 }
 
@@ -511,6 +557,20 @@ go_register_toolchains({{if .Nogo}}nogo = "{{.Nogo}}"{{end}})
 {{.Suffix}}
 `))
 
+type moduleFileTemplateInfo struct {
+	RulesGoPath string
+	Suffix      string
+}
+
+var defaultModuleBazelTpl = template.Must(template.New("").Parse(`
+bazel_dep(name = "rules_go", version = "", repo_name = "io_bazel_rules_go")
+local_path_override(
+    module_name = "rules_go",
+    path = "{{.RulesGoPath}}",
+)
+{{.Suffix}}
+`))
+
 func copyOrLink(dstPath, srcPath string) error {
 	if err := os.MkdirAll(filepath.Dir(dstPath), 0777); err != nil {
 		return err

tests/core/nogo/bzlmod/BUILD.bazel

@@ -0,0 +1,6 @@
+load("@io_bazel_rules_go//go/tools/bazel_testing:def.bzl", "go_bazel_test")
+
+go_bazel_test(
+    name = "includes_exclude_test",
+    srcs = ["includes_excludes_test.go"],
+)

tests/core/nogo/bzlmod/README.rst

@@ -0,0 +1,15 @@
+Nogo Bzlmod configuration
+==================
+
+.. _nogo: /go/nogo.rst
+.. _Bzlmod: /docs/go/core/bzlmod.md
+
+Tests that verify nogo_ works when configured from ``MODULE.bazel``.
+
+.. contents::
+
+includes_excludes_test
+-----------
+
+Verifies that `go_library`_ targets can be built in default configurations with
+nogo with includes and excludes being honored.

tests/core/nogo/bzlmod/includes_excludes_test.go

@@ -0,0 +1,126 @@
+// Copyright 2019 The Bazel Authors. All rights reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//    http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package includes_excludes_test
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/bazelbuild/rules_go/go/tools/bazel_testing"
+)
+
+func TestMain(m *testing.M) {
+	bazel_testing.TestMain(m, bazel_testing.Args{
+		Nogo: "@io_bazel_rules_go//:tools_nogo",
+		Main: `
+-- BUILD.bazel --
+load("@io_bazel_rules_go//go:def.bzl", "go_library", "nogo", "TOOLS_NOGO")
+
+nogo(
+    name = "my_nogo",
+    visibility = ["//visibility:public"],
+    deps = TOOLS_NOGO,
+)
+
+go_library(
+    name = "lib",
+    srcs = ["lib.go"],
+    importpath = "example.com/lib",
+)    
+
+-- lib.go --
+package lib
+
+func shadowed() string {
+	foo := "original"
+	if foo == "original" {
+		foo := "shadow"
+		return foo
+	}
+	return foo
+}
+
+-- go/BUILD.bazel --
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "lib",
+    srcs = ["lib.go"],
+    importpath = "example.com/go/lib",
+)    
+
+-- go/lib.go --
+package lib
+
+func shadowed() string {
+	foo := "original"
+	if foo == "original" {
+		foo := "shadow"
+		return foo
+	}
+	return foo
+}
+
+-- go/third_party/BUILD.bazel --
+load("@io_bazel_rules_go//go:def.bzl", "go_library")
+
+go_library(
+    name = "lib",
+    srcs = ["lib.go"],
+    importpath = "example.com/go/third_party/lib",
+)    
+
+-- go/third_party/lib.go --
+package lib
+
+func shadowed() string {
+	foo := "original"
+	if foo == "original" {
+		foo := "shadow"
+		return foo
+	}
+	return foo
+}
+`,
+		ModuleFileSuffix: `
+go_sdk = use_extension("@io_bazel_rules_go//go:extensions.bzl", "go_sdk")
+go_sdk.nogo(
+    nogo = "//:my_nogo",
+    includes = ["//go:__subpackages__"],
+    excludes = ["//go/third_party:__subpackages__"],
+)
+`,
+	})
+}
+
+func TestNotIncluded(t *testing.T) {
+	if err := bazel_testing.RunBazel("build", "//:lib"); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestIncluded(t *testing.T) {
+	if err := bazel_testing.RunBazel("build", "//go:lib"); err == nil {
+		t.Fatal("Expected build to fail")
+	} else if !strings.Contains(err.Error(), "lib.go:6:3: declaration of \"foo\" shadows declaration at line 4 (shadow)") {
+		t.Fatalf("Expected error to contain \"lib.go:6:3: declaration of \"foo\" shadows declaration at line 4 (shadow)\", got %s", err)
+	}
+}
+
+func TestExcluded(t *testing.T) {
+	if err := bazel_testing.RunBazel("build", "//go/third_party:lib"); err != nil {
+		t.Fatal(err)
+	}
+}