1 files changed, 121 insertions, 0 deletions
diff --git a/tests/runfiles/fs_test.go b/tests/runfiles/fs_test.go
new file mode 100644
index 00000000..3b66c480
--- /dev/null
+++ b/tests/runfiles/fs_test.go
@@ -0,0 +1,121 @@
+// Copyright 2021 Google LLC
+//
+// 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
+//
+//     https://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.
+
+//go:build go1.16
+// +build go1.16
+
+package runfiles_test
+
+import (
+	"io"
+	"io/fs"
+	"os"
+	"path/filepath"
+	"runtime"
+	"testing"
+	"testing/fstest"
+
+	"github.com/bazelbuild/rules_go/go/runfiles"
+)
+
+func TestFS(t *testing.T) {
+	fsys, err := runfiles.New()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	// Ensure that the Runfiles object implements FS interfaces.
+	var _ fs.FS = fsys
+	var _ fs.StatFS = fsys
+	var _ fs.ReadFileFS = fsys
+
+	if runtime.GOOS == "windows" {
+		// Currently the result of
+		//
+		//  fsys.Rlocation("io_bazel_rules_go/go/runfiles/test.txt")
+		//  fsys.Rlocation("bazel_tools/tools/bash/runfiles/runfiles.bash")
+		//  fsys.Rlocation("io_bazel_rules_go/go/runfiles/testprog/testprog")
+		//
+		// would be a full path like these
+		//
+		//  C:\b\bk-windows-1z0z\bazel\rules-go-golang\go\tools\bazel\runfiles\test.txt
+		//  C:\b\zslxztin\external\bazel_tools\tools\bash\runfiles\runfiles.bash
+		//  C:\b\pm4ep4b2\execroot\io_bazel_rules_go\bazel-out\x64_windows-fastbuild\bin\go\tools\bazel\runfiles\testprog\testprog
+		//
+		// Which does not follow any particular patter / rules.
+		// This makes it very hard to define what we are looking for on Windows.
+		// So let's skip this for now.
+		return
+	}
+
+	expected1 := "io_bazel_rules_go/tests/runfiles/test.txt"
+	expected2 := "io_bazel_rules_go/tests/runfiles/testprog/testprog_/testprog"
+	expected3 := "bazel_tools/tools/bash/runfiles/runfiles.bash"
+	if err := fstest.TestFS(fsys, expected1, expected2, expected3); err != nil {
+		t.Error(err)
+	}
+}
+
+func TestFS_empty(t *testing.T) {
+	dir := t.TempDir()
+	manifest := filepath.Join(dir, "manifest")
+	if err := os.WriteFile(manifest, []byte("__init__.py \n"), 0o600); err != nil {
+		t.Fatal(err)
+	}
+	fsys, err := runfiles.New(runfiles.ManifestFile(manifest), runfiles.ProgramName("/invalid"), runfiles.Directory("/invalid"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	t.Run("Open", func(t *testing.T) {
+		fd, err := fsys.Open("__init__.py")
+		if err != nil {
+			t.Fatal(err)
+		}
+		defer fd.Close()
+		got, err := io.ReadAll(fd)
+		if err != nil {
+			t.Error(err)
+		}
+		if len(got) != 0 {
+			t.Errorf("got nonempty contents: %q", got)
+		}
+	})
+	t.Run("Stat", func(t *testing.T) {
+		got, err := fsys.Stat("__init__.py")
+		if err != nil {
+			t.Fatal(err)
+		}
+		if got.Name() != "__init__.py" {
+			t.Errorf("Name: got %q, want %q", got.Name(), "__init__.py")
+		}
+		if got.Size() != 0 {
+			t.Errorf("Size: got %d, want %d", got.Size(), 0)
+		}
+		if !got.Mode().IsRegular() {
+			t.Errorf("IsRegular: got %v, want %v", got.Mode().IsRegular(), true)
+		}
+		if got.IsDir() {
+			t.Errorf("IsDir: got %v, want %v", got.IsDir(), false)
+		}
+	})
+	t.Run("ReadFile", func(t *testing.T) {
+		got, err := fsys.ReadFile("__init__.py")
+		if err != nil {
+			t.Error(err)
+		}
+		if len(got) != 0 {
+			t.Errorf("got nonempty contents: %q", got)
+		}
+	})
+}