Add --strict_error flag to conformance tool (#25)

Defaulting it to off. This should be turned on for any implementations
that can type-check before running the program, so currently only
cel-go/protovalidate-go. This will allow others (like cc, python, java,
etc) to enable --strict mode.

proto/protovalidate-testing/buf/validate/conformance/harness/results.proto

@@ -28,6 +28,8 @@ message ResultOptions {
 
   // If the violation message must be an exact match.
   bool strict_message = 5;
+  // If the distinciton between runtime and compile time errors must be exact.
+  bool strict_error = 6;
 }
 
 message ResultSet {

tools/protovalidate-conformance/config.go

@@ -33,6 +33,7 @@ type config struct {
 	verbose            bool
 	strict             bool
 	strictMessage      bool
+	strictError        bool
 	proto              bool
 	json               bool
 	print              bool
@@ -57,6 +58,7 @@ func parseFlags() config {
 	flag.BoolVarP(&cfg.verbose, "verbose", "v", cfg.verbose, "verbose output")
 	flag.BoolVar(&cfg.strict, "strict", cfg.strict, "strict mode")
 	flag.BoolVar(&cfg.strictMessage, "strict_message", cfg.strictMessage, "require that violation messages match the expected message exactly")
+	flag.BoolVar(&cfg.strictError, "strict_error", cfg.strictError, "require that compile-time errors are distinguished from runtime errors")
 	flag.BoolVar(&cfg.json, "json", cfg.json, "return results as JSON to stdout")
 	flag.BoolVar(&cfg.proto, "proto", cfg.proto, "return results as binary serialized proto to stdout")
 	flag.BoolVar(&cfg.dump, "dump", cfg.dump, "output the expected results, without a command")

tools/protovalidate-conformance/internal/results/result.go

@@ -166,7 +166,7 @@ func (c compilationErrorResult) IsSuccessWith(other Result, options *harness.Res
 	case compilationErrorResult:
 		return true
 	case runtimeErrorResult:
-		return !options.Strict
+		return !options.StrictError
 	default:
 		return false
 	}

tools/protovalidate-conformance/main.go

@@ -35,6 +35,7 @@ func main() {
 		Verbose:       cfg.verbose,
 		Strict:        cfg.strict,
 		StrictMessage: cfg.strictMessage,
+		StrictError:   cfg.strictError,
 	}
 	resultSet := &results.Set{
 		Options: options,