uri.go: add IsFileURI()

uri.go

@@ -53,6 +53,10 @@ func (u URI) Filename() string {
 	return filepath.FromSlash(filename)
 }
 
+func IsFileURI(uri string) bool {
+	return strings.HasPrefix(uri, FileScheme+hierPart)
+}
+
 func filename(uri URI) (string, error) {
 	u, err := url.ParseRequestURI(string(uri))
 	if err != nil {
@@ -76,7 +80,7 @@ func New(s string) URI {
 		s = u
 	}
 
-	if strings.HasPrefix(s, FileScheme+hierPart) {
+	if IsFileURI(s) {
 		return URI(s)
 	}
 

uri_test.go

@@ -140,3 +140,45 @@ func TestFrom(t *testing.T) {
 		})
 	}
 }
+
+func TestIsFileURI(t *testing.T) {
+	tests := []struct {
+		name string
+		s    string
+		want bool
+	}{
+		{
+			name: "File Scheme",
+			s:    "file://code.visualstudio.com/docs/extensions/overview.md",
+			want: true,
+		},
+		{
+			name: "HTTP Scheme",
+			s:    "http://code.visualstudio.com/docs/extensions/overview.md",
+			want: false,
+		},
+		{
+			name: "Empty string",
+			s:    "",
+			want: false,
+		},
+		{
+			name: "Random string",
+			s:    "8o3hsXTXRG",
+			want: false,
+		},
+	}
+
+	for _, tt := range tests {
+		tt := tt
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			got := IsFileURI(tt.s)
+
+			if got != tt.want {
+				t.Errorf("want '%v' != got '%v'", tt.want, got)
+			}
+		})
+	}
+}