Add generic raw output validators

internal/validators/generic/valid_json_schema/validator.go

@@ -0,0 +1,81 @@
+package validjsonschema
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+
+	"github.com/santhosh-tekuri/jsonschema/v6"
+
+	"gitea.maximumdirect.net/eric/notarius/internal/framework/contracts"
+	"gitea.maximumdirect.net/eric/notarius/internal/framework/pipeline"
+)
+
+const Key = "generic/valid_json_schema"
+const ReasonCodeInvalidJSON = "invalid_json"
+const ReasonCodeSchemaInvalid = "json_schema_invalid"
+
+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 len(req.Schema.JSONSchema) == 0 {
+		return contracts.ValidationResult{}, fmt.Errorf("response schema content is not available")
+	}
+
+	instance, err := jsonschema.UnmarshalJSON(bytes.NewReader(req.Payload.Content))
+	if err != nil {
+		return contracts.ValidationResult{
+			Approved:   false,
+			ReasonCode: ReasonCodeInvalidJSON,
+			Message:    "payload is not valid JSON",
+		}, nil
+	}
+
+	schemaDocument, err := jsonschema.UnmarshalJSON(bytes.NewReader(req.Schema.JSONSchema))
+	if err != nil {
+		return contracts.ValidationResult{}, fmt.Errorf("parse response schema: %w", err)
+	}
+	compiler := jsonschema.NewCompiler()
+	if err := compiler.AddResource("schema.json", schemaDocument); err != nil {
+		return contracts.ValidationResult{}, fmt.Errorf("load response schema: %w", err)
+	}
+	schema, err := compiler.Compile("schema.json")
+	if err != nil {
+		return contracts.ValidationResult{}, fmt.Errorf("compile response schema: %w", err)
+	}
+	if err := schema.Validate(instance); err != nil {
+		return contracts.ValidationResult{
+			Approved:   false,
+			ReasonCode: ReasonCodeSchemaInvalid,
+			Message:    "payload does not conform to response schema",
+		}, 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
+	})
+}