diff --git a/os/gfile/gfile_z_exmaple_basic_test.go b/os/gfile/gfile_z_exmaple_basic_test.go
index 188d0a374..3f9d87ded 100644
--- a/os/gfile/gfile_z_exmaple_basic_test.go
+++ b/os/gfile/gfile_z_exmaple_basic_test.go
@@ -340,14 +340,17 @@ func ExampleIsReadable() {
 func ExampleIsWritable() {
 	// init
 	var (
-		path = gfile.Pwd() + gfile.Separator + "testdata/readline/file.log"
+		path = gfile.Pwd() + gfile.Separator + "testdata/readline/"
+		file = "file.log"
 	)
 
 	// Checks whether given `path` is writable.
 	fmt.Println(gfile.IsWritable(path))
+	fmt.Println(gfile.IsWritable(path + file))
 
 	// Output:
 	// true
+	// true
 }
 
 func ExampleChmod() {
diff --git a/os/gfile/gfile_z_unit_contents_test.go b/os/gfile/gfile_z_unit_contents_test.go
index 3d38e18a6..bb9b01da3 100644
--- a/os/gfile/gfile_z_unit_contents_test.go
+++ b/os/gfile/gfile_z_unit_contents_test.go
@@ -323,7 +323,7 @@ func Test_Home(t *testing.T) {
 			err   error
 		)
 
-		reads, err = gfile.Home()
+		reads, err = gfile.Home("a", "b")
 		t.Assert(err, nil)
 		t.AssertNE(reads, "")
 	})
diff --git a/os/gfile/gfile_z_unit_copy_test.go b/os/gfile/gfile_z_unit_copy_test.go
index 73cb2689f..6a00895fa 100644
--- a/os/gfile/gfile_z_unit_copy_test.go
+++ b/os/gfile/gfile_z_unit_copy_test.go
@@ -28,7 +28,8 @@ func Test_Copy(t *testing.T) {
 		defer delTestFiles(topath)
 
 		t.Assert(gfile.IsFile(testpath()+topath), true)
-		t.AssertNE(gfile.Copy("", ""), nil)
+		t.AssertNE(gfile.Copy(paths, ""), nil)
+		t.AssertNE(gfile.Copy("", topath), nil)
 	})
 }
 
@@ -46,7 +47,8 @@ func Test_CopyFile(t *testing.T) {
 		defer delTestFiles(topath)
 
 		t.Assert(gfile.IsFile(testpath()+topath), true)
-		t.AssertNE(gfile.CopyFile("", ""), nil)
+		t.AssertNE(gfile.CopyFile(paths, ""), nil)
+		t.AssertNE(gfile.CopyFile("", topath), nil)
 	})
 	// Content replacement.
 	gtest.C(t, func(t *gtest.T) {
@@ -128,5 +130,8 @@ func Test_CopyDir(t *testing.T) {
 		t.Assert(err, nil)
 		t.Assert(gfile.GetContents(src), srcContent)
 		t.Assert(gfile.GetContents(dst), srcContent)
+
+		t.AssertNE(gfile.CopyDir(gfile.Dir(src), ""), nil)
+		t.AssertNE(gfile.CopyDir("", gfile.Dir(dst)), nil)
 	})
 }
diff --git a/os/gfile/gfile_z_unit_size_test.go b/os/gfile/gfile_z_unit_size_test.go
index f5f97c506..8e410a97b 100644
--- a/os/gfile/gfile_z_unit_size_test.go
+++ b/os/gfile/gfile_z_unit_size_test.go
@@ -68,6 +68,11 @@ func Test_StrToSize(t *testing.T) {
 		t.Assert(gfile.StrToSize("8.53P"), gconv.Int64(8.53*1024*1024*1024*1024*1024))
 		t.Assert(gfile.StrToSize("8.53PB"), gconv.Int64(8.53*1024*1024*1024*1024*1024))
 		t.Assert(gfile.StrToSize("8.01EB"), gconv.Int64(8.01*1024*1024*1024*1024*1024*1024))
+		t.Assert(gfile.StrToSize("0.01ZB"), gconv.Int64(0.01*1024*1024*1024*1024*1024*1024*1024))
+		t.Assert(gfile.StrToSize("0.01YB"), gconv.Int64(0.01*1024*1024*1024*1024*1024*1024*1024*1024))
+		t.Assert(gfile.StrToSize("0.01BB"), gconv.Int64(0.01*1024*1024*1024*1024*1024*1024*1024*1024*1024))
+		t.Assert(gfile.StrToSize("0.01AB"), gconv.Int64(-1))
+		t.Assert(gfile.StrToSize("123456789"), 123456789)
 	})
 }
 
diff --git a/os/gfile/gfile_z_unit_test.go b/os/gfile/gfile_z_unit_test.go
index 1b0c6596b..e290621e7 100644
--- a/os/gfile/gfile_z_unit_test.go
+++ b/os/gfile/gfile_z_unit_test.go
@@ -571,6 +571,7 @@ func Test_Dir(t *testing.T) {
 
 		t.Assert(readlPath, testpath())
 
+		t.Assert(len(gfile.Dir(".")) > 0, true)
 	})
 }
 
@@ -667,3 +668,15 @@ func Test_MainPkgPath(t *testing.T) {
 		t.Assert(reads, "")
 	})
 }
+
+func Test_SelfName(t *testing.T) {
+	gtest.C(t, func(t *gtest.T) {
+		t.Assert(len(gfile.SelfName()) > 0, true)
+	})
+}
+
+func Test_MTimestamp(t *testing.T) {
+	gtest.C(t, func(t *gtest.T) {
+		t.Assert(gfile.MTimestamp(gfile.Temp()) > 0, true)
+	})
+}