fix(grpc): add more checks for tag validation

grpcv1_test.go

@@ -0,0 +1,42 @@
+package headscale
+
+import "testing"
+
+func Test_validateTag(t *testing.T) {
+	type args struct {
+		tag string
+	}
+	tests := []struct {
+		name    string
+		args    args
+		wantErr bool
+	}{
+		{
+			name:    "valid tag",
+			args:    args{tag: "tag:test"},
+			wantErr: false,
+		},
+		{
+			name:    "tag without tag prefix",
+			args:    args{tag: "test"},
+			wantErr: true,
+		},
+		{
+			name:    "uppercase tag",
+			args:    args{tag: "tag:tEST"},
+			wantErr: true,
+		},
+		{
+			name:    "tag that contains space",
+			args:    args{tag: "tag:this is a spaced tag"},
+			wantErr: true,
+		},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if err := validateTag(tt.args.tag); (err != nil) != tt.wantErr {
+				t.Errorf("validateTag() error = %v, wantErr %v", err, tt.wantErr)
+			}
+		})
+	}
+}