Add generic raw output validators

internal/validators/generic/valid_json/validator.go

@@ -0,0 +1,52 @@
+package validjson
+
+import (
+	"context"
+	"encoding/json"
+
+	"gitea.maximumdirect.net/eric/notarius/internal/framework/contracts"
+	"gitea.maximumdirect.net/eric/notarius/internal/framework/pipeline"
+)
+
+const Key = "generic/valid_json"
+const ReasonCodeInvalidJSON = "invalid_json"
+
+var _ contracts.Validator = (*Validator)(nil)
+
+type Validator struct{}
+
+func New() *Validator {
+	return &Validator{}
+}
+
+func (v *Validator) Name() string {
+	return Key
+}
+
+func (v *Validator) ExecutionClass() contracts.ExecutionClass {
+	return contracts.ExecutionClassDeterministic
+}
+
+func (v *Validator) Validate(ctx context.Context, req contracts.ValidationRequest) (contracts.ValidationResult, error) {
+	if !json.Valid(req.Payload.Content) {
+		return contracts.ValidationResult{
+			Approved:   false,
+			ReasonCode: ReasonCodeInvalidJSON,
+			Message:    "payload is not valid JSON",
+		}, nil
+	}
+	return contracts.ValidationResult{Approved: true}, nil
+}
+
+func Spec() pipeline.ValidatorSpec {
+	return pipeline.ValidatorSpec{
+		Key:            Key,
+		ExecutionClass: contracts.ExecutionClassDeterministic,
+	}
+}
+
+func Register(registry *pipeline.ValidatorRegistry) error {
+	return registry.RegisterWithSpec(Spec(), func() (contracts.Validator, error) {
+		return New(), nil
+	})
+}

internal/validators/generic/valid_json/validator_test.go

@@ -0,0 +1,66 @@
+package validjson
+
+import (
+	"context"
+	"testing"
+
+	"gitea.maximumdirect.net/eric/notarius/internal/framework/contracts"
+	"gitea.maximumdirect.net/eric/notarius/internal/framework/pipeline"
+)
+
+func TestValidatorAcceptsValidJSON(t *testing.T) {
+	tests := []string{
+		`{"value":true}`,
+		`[1,2,3]`,
+		`"value"`,
+	}
+	for _, payload := range tests {
+		result, err := New().Validate(context.Background(), requestWithPayload(payload))
+		if err != nil {
+			t.Fatalf("Validate(%s) error = %v, want nil", payload, err)
+		}
+		if !result.Approved {
+			t.Fatalf("Validate(%s) = %#v, want approved", payload, result)
+		}
+	}
+}
+
+func TestValidatorRejectsInvalidJSON(t *testing.T) {
+	result, err := New().Validate(context.Background(), requestWithPayload(`{"value":`))
+	if err != nil {
+		t.Fatalf("Validate() error = %v, want nil", err)
+	}
+	if result.Approved {
+		t.Fatalf("Approved = true, want false")
+	}
+	if result.ReasonCode != ReasonCodeInvalidJSON {
+		t.Fatalf("ReasonCode = %q, want %q", result.ReasonCode, ReasonCodeInvalidJSON)
+	}
+}
+
+func TestSpecAndRegister(t *testing.T) {
+	if Spec().Key != Key || Spec().ExecutionClass != contracts.ExecutionClassDeterministic {
+		t.Fatalf("Spec() = %#v, want key and deterministic execution", Spec())
+	}
+
+	registry := pipeline.NewValidatorRegistry()
+	if err := Register(registry); err != nil {
+		t.Fatalf("Register() error = %v, want nil", err)
+	}
+	validator, err := registry.Build(Key)
+	if err != nil {
+		t.Fatalf("Build(%q) error = %v, want nil", Key, err)
+	}
+	if validator.Name() != Key {
+		t.Fatalf("Name() = %q, want %q", validator.Name(), Key)
+	}
+}
+
+func requestWithPayload(payload string) contracts.ValidationRequest {
+	return contracts.ValidationRequest{
+		Payload: contracts.RawPayload{
+			Content:   []byte(payload),
+			MediaType: "application/json",
+		},
+	}
+}