diff --git a/uri_test.go b/uri_test.go
index 9c934a1..1da32c4 100644
--- a/uri_test.go
+++ b/uri_test.go
@@ -15,19 +15,49 @@ import (
 
 func TestParse(t *testing.T) {
 	tests := []struct {
-		name string
-		s    string
-		want *uri.URI
+		name    string
+		s       string
+		want    *uri.URI
+		wantErr bool
 	}{
 		{
-			name: "Valid",
-			s:    "https://code.visualstudio.com/docs/extensions/overview#frag",
+			name: "ValidFileScheme",
+			s:    "file://code.visualstudio.com/docs/extensions/overview.md",
 			want: &uri.URI{
-				Scheme:    "https",
+				Scheme:    uri.FileScheme,
+				Authority: "code.visualstudio.com",
+				Path:      "/docs/extensions/overview.md",
+				FsPath:    filepath.FromSlash("/docs/extensions/overview.md"),
+			},
+			wantErr: false,
+		},
+		{
+			name: "ValidHTTPScheme",
+			s:    "http://code.visualstudio.com/docs/extensions/overview#frag",
+			want: &uri.URI{
+				Scheme:    uri.HTTPScheme,
 				Authority: "code.visualstudio.com",
 				Path:      "/docs/extensions/overview",
 				Fragment:  "frag",
 			},
+			wantErr: false,
+		},
+		{
+			name: "ValidHTTPSScheme",
+			s:    "https://code.visualstudio.com/docs/extensions/overview#frag",
+			want: &uri.URI{
+				Scheme:    uri.HTTPSScheme,
+				Authority: "code.visualstudio.com",
+				Path:      "/docs/extensions/overview",
+				Fragment:  "frag",
+			},
+			wantErr: false,
+		},
+		{
+			name:    "Invalid",
+			s:       "foo://user@example.com:8042/over/there?name=ferret#nose",
+			want:    new(uri.URI),
+			wantErr: true,
 		},
 	}
 	for _, tt := range tests {
@@ -35,7 +65,7 @@ func TestParse(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			t.Parallel()
 
-			if diff := cmp.Diff(uri.Parse(tt.s), tt.want); diff != "" {
+			if diff := cmp.Diff(uri.Parse(tt.s), tt.want, cmp.AllowUnexported(*tt.want)); (diff != "") != tt.wantErr {
 				t.Errorf("%s: (-got, +want)\n%s", tt.name, diff)
 			}
 		})
@@ -44,18 +74,104 @@ func TestParse(t *testing.T) {
 
 func TestFile(t *testing.T) {
 	tests := []struct {
-		name string
-		path string
-		want *uri.URI
+		name    string
+		path    string
+		want    *uri.URI
+		wantErr bool
 	}{
 		{
-			name: "Valid",
+			name: "ValidFileScheme",
 			path: "/users/me/c#-projects/",
 			want: &uri.URI{
 				Scheme: uri.FileScheme,
 				Path:   "/users/me/c#-projects/",
 				FsPath: filepath.FromSlash("/users/me/c#-projects/"),
 			},
+			wantErr: false,
+		},
+		{
+			name:    "Invalid",
+			path:    "users-me-c#-projects",
+			want:    new(uri.URI),
+			wantErr: true,
+		},
+	}
+	for _, tt := range tests {
+		tt := tt
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			if diff := cmp.Diff(uri.File(tt.path), tt.want, cmp.AllowUnexported(*tt.want)); (diff != "") != tt.wantErr {
+				t.Errorf("%s: (-got, +want)\n%s", tt.name, diff)
+			}
+		})
+	}
+}
+
+func TestFrom(t *testing.T) {
+	type args struct {
+		scheme    string
+		authority string
+		path      string
+		query     string
+		fragment  string
+	}
+	tests := []struct {
+		name string
+		args args
+		want *uri.URI
+	}{
+		{
+			name: "ValidFileScheme",
+			args: args{
+				scheme:    "file",
+				authority: "example.com",
+				path:      "/over/there",
+				query:     "name=ferret",
+				fragment:  "nose",
+			},
+			want: &uri.URI{
+				Scheme:    uri.FileScheme,
+				Authority: "example.com",
+				Path:      "/over/there",
+				FsPath:    filepath.FromSlash("/over/there"),
+				Query:     "name=ferret",
+				Fragment:  "nose",
+			},
+		},
+		{
+			name: "ValidHTTPScheme",
+			args: args{
+				scheme:    "http",
+				authority: "example.com:8042",
+				path:      "/over/there",
+				query:     "name=ferret",
+				fragment:  "nose",
+			},
+			want: &uri.URI{
+				Scheme:    uri.HTTPScheme,
+				Authority: "example.com:8042",
+				Path:      "/over/there",
+				Query:     "name=ferret",
+				Fragment:  "nose",
+			},
+		},
+		{
+			name: "ValidHTTPSScheme",
+			args: args{
+				scheme:    "https",
+				authority: "example.com:8042",
+				path:      "/over/there",
+				query:     "name=ferret",
+				fragment:  "nose",
+			},
+			want: &uri.URI{
+				Scheme:    uri.HTTPSScheme,
+				Authority: "example.com:8042",
+				Path:      "/over/there",
+				Query:     "name=ferret",
+				Fragment:  "nose",
+			},
 		},
 	}
 	for _, tt := range tests {
@@ -63,9 +179,82 @@ func TestFile(t *testing.T) {
 		t.Run(tt.name, func(t *testing.T) {
 			t.Parallel()
 
-			if diff := cmp.Diff(uri.File(tt.path), tt.want); diff != "" {
+			if diff := cmp.Diff(uri.From(tt.args.scheme, tt.args.authority, tt.args.path, tt.args.query, tt.args.fragment), tt.want, cmp.AllowUnexported(*tt.want)); diff != "" {
 				t.Errorf("%s: (-got, +want)\n%s", tt.name, diff)
 			}
 		})
 	}
 }
+
+func TestURI_String(t *testing.T) {
+	type fields struct {
+		Authority string
+		Fragment  string
+		FsPath    string
+		Path      string
+		Query     string
+		Scheme    string
+	}
+	tests := []struct {
+		name   string
+		fields fields
+		want   string
+	}{
+		{
+			name: "ValidFileScheme",
+			fields: fields{
+				Authority: "code.visualstudio.com",
+				Path:      "/docs/extensions/overview.md",
+				FsPath:    filepath.FromSlash("/docs/extensions/overview.md"),
+				Scheme:    string(uri.FileScheme),
+			},
+			want: "file://code.visualstudio.com/docs/extensions/overview.md",
+		},
+		{
+			name: "ValidHTTPScheme",
+			fields: fields{
+				Authority: "code.visualstudio.com",
+				Fragment:  "frag",
+				Path:      "/docs/extensions/overview",
+				FsPath:    filepath.FromSlash("/docs/extensions/overview"),
+				Query:     "test",
+				Scheme:    string(uri.HTTPScheme),
+			},
+			want: "http://code.visualstudio.com/docs/extensions/overview?test#frag",
+		},
+		{
+			name: "ValidHTTPSScheme",
+			fields: fields{
+				Authority: "code.visualstudio.com",
+				Fragment:  "frag",
+				Path:      "/docs/extensions/overview",
+				FsPath:    filepath.FromSlash("/docs/extensions/overview"),
+				Query:     "test",
+				Scheme:    string(uri.HTTPSScheme),
+			},
+			want: "https://code.visualstudio.com/docs/extensions/overview?test#frag",
+		},
+	}
+	for _, tt := range tests {
+		tt := tt
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+
+			u := &uri.URI{
+				Authority: tt.fields.Authority,
+				Fragment:  tt.fields.Fragment,
+				FsPath:    tt.fields.FsPath,
+				Path:      tt.fields.Path,
+				Query:     tt.fields.Query,
+				Scheme:    tt.fields.Scheme,
+			}
+
+			if got := u.String(); !cmp.Equal(got, tt.want) {
+				t.Errorf("URI.String() = %v, want %v", got, tt.want)
+			}
+			if got2 := u.String(); !cmp.Equal(got2, tt.want) { // cache with u.formatted
+				t.Errorf("URI.String() = %v, want %v", got2, tt.want)
+			}
+		})
+	}
+}