diff --git a/finder/fs/readdir_test.go b/finder/fs/readdir_test.go
new file mode 100644
index 0000000..24a6d18
--- /dev/null
+++ b/finder/fs/readdir_test.go
@@ -0,0 +1,312 @@
+// Copyright 2017 Google Inc. 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 fs
+
+import (
+	"os"
+	"reflect"
+	"runtime"
+	"testing"
+)
+
+func TestParseDirent(t *testing.T) {
+	testCases := []struct {
+		name string
+		in   []byte
+		out  []*dirEntryInfo
+	}{
+		{
+			// Test that type DT_DIR is translated to os.ModeDir
+			name: "dir",
+			in: []byte{
+				// __ino64_t d_ino;
+				0xfb, 0x10, 0xe6, 0x00, 0x00, 0x00, 0x00, 0x00,
+				// __off64_t d_off;
+				0xeb, 0x85, 0x20, 0x91, 0xb9, 0x14, 0x34, 0x03,
+				// unsigned short int d_reclen;
+				0x28, 0x00,
+				// unsigned char d_type;
+				0x04,
+				// char d_name[];
+				0x2e, 0x6d, 0x6f, 0x64, 0x75, 0x6c, 0x65, 0x5f, 0x70, 0x61, 0x74, 0x68, 0x73,
+				0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			},
+			out: []*dirEntryInfo{
+				{".module_paths", os.ModeDir, true},
+			},
+		},
+		{
+			// Test that type DT_REG is translated to a regular file
+			name: "file",
+			in: []byte{
+				// __ino64_t d_ino;
+				0xfb, 0x10, 0xe6, 0x00, 0x00, 0x00, 0x00, 0x00,
+				// __off64_t d_off;
+				0xeb, 0x85, 0x20, 0x91, 0xb9, 0x14, 0x34, 0x03,
+				// unsigned short int d_reclen;
+				0x28, 0x00,
+				// unsigned char d_type;
+				0x08,
+				// char d_name[];
+				0x2e, 0x6d, 0x6f, 0x64, 0x75, 0x6c, 0x65, 0x5f, 0x70, 0x61, 0x74, 0x68, 0x73,
+				0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			},
+			out: []*dirEntryInfo{
+				{".module_paths", 0, true},
+			},
+		},
+		{
+			// Test that type DT_LNK is translated to a regular os.ModeSymlink
+			name: "symlink",
+			in: []byte{
+				// __ino64_t d_ino;
+				0xfb, 0x10, 0xe6, 0x00, 0x00, 0x00, 0x00, 0x00,
+				// __off64_t d_off;
+				0xeb, 0x85, 0x20, 0x91, 0xb9, 0x14, 0x34, 0x03,
+				// unsigned short int d_reclen;
+				0x28, 0x00,
+				// unsigned char d_type;
+				0x0a,
+				// char d_name[];
+				0x2e, 0x6d, 0x6f, 0x64, 0x75, 0x6c, 0x65, 0x5f, 0x70, 0x61, 0x74, 0x68, 0x73,
+				0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			},
+			out: []*dirEntryInfo{
+				{".module_paths", os.ModeSymlink, true},
+			},
+		},
+		{
+			// Test that type DT_UNKNOWN sets modeExists: false
+			name: "unknown",
+			in: []byte{
+				// __ino64_t d_ino;
+				0xfb, 0x10, 0xe6, 0x00, 0x00, 0x00, 0x00, 0x00,
+				// __off64_t d_off;
+				0xeb, 0x85, 0x20, 0x91, 0xb9, 0x14, 0x34, 0x03,
+				// unsigned short int d_reclen;
+				0x28, 0x00,
+				// unsigned char d_type;
+				0x00,
+				// char d_name[];
+				0x2e, 0x6d, 0x6f, 0x64, 0x75, 0x6c, 0x65, 0x5f, 0x70, 0x61, 0x74, 0x68, 0x73,
+				0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			},
+			out: []*dirEntryInfo{
+				{".module_paths", 0, false},
+			},
+		},
+		{
+			// Test a name with no padding after the null terminator
+			name: "no padding",
+			in: []byte{
+				// __ino64_t d_ino;
+				0xfb, 0x10, 0xe6, 0x00, 0x00, 0x00, 0x00, 0x00,
+				// __off64_t d_off;
+				0xeb, 0x85, 0x20, 0x91, 0xb9, 0x14, 0x34, 0x03,
+				// unsigned short int d_reclen;
+				0x20, 0x00,
+				// unsigned char d_type;
+				0x04,
+				// char d_name[];
+				0x2e, 0x6d, 0x6f, 0x64, 0x75, 0x6c, 0x65, 0x5f, 0x70, 0x61, 0x74, 0x68, 0x00,
+			},
+			out: []*dirEntryInfo{
+				{".module_path", os.ModeDir, true},
+			},
+		},
+		{
+			// Test two sequential entries
+			name: "two entries",
+			in: []byte{
+				// __ino64_t d_ino;
+				0xfb, 0x10, 0xe6, 0x00, 0x00, 0x00, 0x00, 0x00,
+				// __off64_t d_off;
+				0xeb, 0x85, 0x20, 0x91, 0xb9, 0x14, 0x34, 0x03,
+				// unsigned short int d_reclen;
+				0x28, 0x00,
+				// unsigned char d_type;
+				0x04,
+				// char d_name[];
+				0x2e, 0x6d, 0x6f, 0x64, 0x75, 0x6c, 0x65, 0x5f, 0x70, 0x61, 0x74, 0x68, 0x73,
+				0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+
+				// __ino64_t d_ino;
+				0xfb, 0x10, 0xe6, 0x00, 0x00, 0x00, 0x00, 0x00,
+				// __off64_t d_off;
+				0xeb, 0x85, 0x20, 0x91, 0xb9, 0x14, 0x34, 0x03,
+				// unsigned short int d_reclen;
+				0x28, 0x00,
+				// unsigned char d_type;
+				0x04,
+				// char d_name[];
+				0x2e, 0x6d, 0x6f, 0x64, 0x75, 0x6c, 0x65, 0x5f, 0x70, 0x61, 0x74, 0x68, 0x74,
+				0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			},
+			out: []*dirEntryInfo{
+				{".module_paths", os.ModeDir, true},
+				{".module_patht", os.ModeDir, true},
+			},
+		},
+		{
+			// Test two sequential entries with no padding between them
+			name: "two entries no padding",
+			in: []byte{
+				// __ino64_t d_ino;
+				0xfb, 0x10, 0xe6, 0x00, 0x00, 0x00, 0x00, 0x00,
+				// __off64_t d_off;
+				0xeb, 0x85, 0x20, 0x91, 0xb9, 0x14, 0x34, 0x03,
+				// unsigned short int d_reclen;
+				0x20, 0x00,
+				// unsigned char d_type;
+				0x04,
+				// char d_name[];
+				0x2e, 0x6d, 0x6f, 0x64, 0x75, 0x6c, 0x65, 0x5f, 0x70, 0x61, 0x74, 0x68, 0x00,
+
+				// __ino64_t d_ino;
+				0xfb, 0x10, 0xe6, 0x00, 0x00, 0x00, 0x00, 0x00,
+				// __off64_t d_off;
+				0xeb, 0x85, 0x20, 0x91, 0xb9, 0x14, 0x34, 0x03,
+				// unsigned short int d_reclen;
+				0x28, 0x00,
+				// unsigned char d_type;
+				0x04,
+				// char d_name[];
+				0x2e, 0x6d, 0x6f, 0x64, 0x75, 0x6c, 0x65, 0x5f, 0x70, 0x61, 0x74, 0x68, 0x73,
+				0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			},
+			out: []*dirEntryInfo{
+				{".module_path", os.ModeDir, true},
+				{".module_paths", os.ModeDir, true},
+			},
+		},
+		{
+			// Test an empty buffer.  This shouldn't happen in practice because
+			// readdir doesn't call parseDirent if no bytes were returned.
+			name: "empty",
+			in:   []byte{},
+			out:  nil,
+		},
+		{
+			name: "missing null terminator",
+			in: []byte{
+				// __ino64_t d_ino;
+				0xfb, 0x10, 0xe6, 0x00, 0x00, 0x00, 0x00, 0x00,
+				// __off64_t d_off;
+				0xeb, 0x85, 0x20, 0x91, 0xb9, 0x14, 0x34, 0x03,
+				// unsigned short int d_reclen;
+				0x20, 0x00,
+				// unsigned char d_type;
+				0x04,
+				// char d_name[];
+				0x2e, 0x6d, 0x6f, 0x64, 0x75, 0x6c, 0x65, 0x5f, 0x70, 0x61, 0x74, 0x68, 0x73,
+			},
+			out: []*dirEntryInfo{
+				{".module_paths", os.ModeDir, true},
+			},
+		},
+		{
+			// Test two sequential entries where the first has an incorrect d_reclen.
+			// Should return with no entries.
+			name: "two entries first malformed",
+			in: []byte{
+				// __ino64_t d_ino;
+				0xfb, 0x10, 0xe6, 0x00, 0x00, 0x00, 0x00, 0x00,
+				// __off64_t d_off;
+				0xeb, 0x85, 0x20, 0x91, 0xb9, 0x14, 0x34, 0x03,
+				// unsigned short int d_reclen;
+				0x10, 0x00,
+				// unsigned char d_type;
+				0x04,
+				// char d_name[];
+				0x2e, 0x6d, 0x6f, 0x64, 0x75, 0x6c, 0x65, 0x5f, 0x70, 0x61, 0x74, 0x68, 0x00,
+
+				// __ino64_t d_ino;
+				0xfb, 0x10, 0xe6, 0x00, 0x00, 0x00, 0x00, 0x00,
+				// __off64_t d_off;
+				0xeb, 0x85, 0x20, 0x91, 0xb9, 0x14, 0x34, 0x03,
+				// unsigned short int d_reclen;
+				0x28, 0x00,
+				// unsigned char d_type;
+				0x04,
+				// char d_name[];
+				0x2e, 0x6d, 0x6f, 0x64, 0x75, 0x6c, 0x65, 0x5f, 0x70, 0x61, 0x74, 0x68, 0x73,
+				0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			},
+			out: nil,
+		},
+		{
+			// Test two sequential entries where the second has an incorrect d_reclen.
+			// Should return the first entry.
+			name: "two entries second malformed",
+			in: []byte{
+				// __ino64_t d_ino;
+				0xfb, 0x10, 0xe6, 0x00, 0x00, 0x00, 0x00, 0x00,
+				// __off64_t d_off;
+				0xeb, 0x85, 0x20, 0x91, 0xb9, 0x14, 0x34, 0x03,
+				// unsigned short int d_reclen;
+				0x28, 0x00,
+				// unsigned char d_type;
+				0x04,
+				// char d_name[];
+				0x2e, 0x6d, 0x6f, 0x64, 0x75, 0x6c, 0x65, 0x5f, 0x70, 0x61, 0x74, 0x68, 0x00,
+
+				// __ino64_t d_ino;
+				0xfb, 0x10, 0xe6, 0x00, 0x00, 0x00, 0x00, 0x00,
+				// __off64_t d_off;
+				0xeb, 0x85, 0x20, 0x91, 0xb9, 0x14, 0x34, 0x03,
+				// unsigned short int d_reclen;
+				0x10, 0x00,
+				// unsigned char d_type;
+				0x04,
+				// char d_name[];
+				0x2e, 0x6d, 0x6f, 0x64, 0x75, 0x6c, 0x65, 0x5f, 0x70, 0x61, 0x74, 0x68, 0x73,
+				0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+			},
+			out: []*dirEntryInfo{
+				{".module_path", os.ModeDir, true},
+			},
+		},
+		{
+			// Test a reclen that goes past the end of the buffer.
+			name: "overrun",
+			in: []byte{
+				// __ino64_t d_ino;
+				0xfb, 0x10, 0xe6, 0x00, 0x00, 0x00, 0x00, 0x00,
+				// __off64_t d_off;
+				0xeb, 0x85, 0x20, 0x91, 0xb9, 0x14, 0x34, 0x03,
+				// unsigned short int d_reclen;
+				0x30, 0x00,
+				// unsigned char d_type;
+				0x04,
+				// char d_name[];
+				0x2e, 0x6d, 0x6f, 0x64, 0x75, 0x6c, 0x65, 0x5f, 0x70, 0x61, 0x74, 0x68, 0x00,
+			},
+			out: nil,
+		},
+	}
+
+	if runtime.GOOS != "linux" {
+		t.Skip("depends on Linux definitions of syscall.Dirent")
+	}
+
+	for _, testCase := range testCases {
+		t.Run(testCase.name, func(t *testing.T) {
+			entries := parseDirent(testCase.in, nil)
+			if !reflect.DeepEqual(testCase.out, entries) {
+				t.Fatalf("expected:\n %v\ngot:\n %v\n", testCase.out, entries)
+			}
+		})
+	}
+}