Run validation based on fields always, keep validation based on mapping optional

.buildkite/pipeline.trigger.integration.tests.sh

@@ -113,7 +113,7 @@ echo "          - build/test-coverage/coverage-*.xml" # these files should not b
 # Add steps to test validation method mappings
 while IFS= read -r -d '' package ; do
     package_name=$(basename "${package}")
-    echo "      - label: \":go: Integration test: ${package_name} (just validate mappings)\""
+    echo "      - label: \":go: Integration test: ${package_name} (validate mappings)\""
     echo "        key: \"integration-parallel-${package_name}-agent-validate-mappings\""
     echo "        command: ./.buildkite/scripts/integration_tests.sh -t test-check-packages-parallel -p ${package_name}"
     echo "        env:"

internal/elasticsearch/client.go

@@ -361,6 +361,16 @@ func (c *Client) SimulateIndexTemplate(ctx context.Context, indexTemplateName st
 		return nil, nil, fmt.Errorf("error unmarshaling mappings: %w", err)
 	}
 
+	// In case there are no dynamic templates, set an empty array
+	if string(preview.Template.Mappings.DynamicTemplates) == "" {
+		preview.Template.Mappings.DynamicTemplates = []byte("[]")
+	}
+
+	// In case there are no mappings defined, set an empty map
+	if string(preview.Template.Mappings.Properties) == "" {
+		preview.Template.Mappings.Properties = []byte("{}")
+	}
+
 	return preview.Template.Mappings.DynamicTemplates, preview.Template.Mappings.Properties, nil
 }
 
@@ -403,5 +413,15 @@ func (c *Client) DataStreamMappings(ctx context.Context, dataStreamName string)
 		mappingsDefinition = v.Mappings
 	}
 
+	// In case there are no dynamic templates, set an empty array
+	if string(mappingsDefinition.DynamicTemplates) == "" {
+		mappingsDefinition.DynamicTemplates = []byte("[]")
+	}
+
+	// In case there are no mappings defined, set an empty map
+	if string(mappingsDefinition.Properties) == "" {
+		mappingsDefinition.Properties = []byte("{}")
+	}
+
 	return mappingsDefinition.DynamicTemplates, mappingsDefinition.Properties, nil
 }

internal/testrunner/runners/system/tester.go

@@ -141,13 +141,11 @@ var (
 type fieldValidationMethod int
 
 const (
-	allMethods fieldValidationMethod = iota
-	fieldsMethod
+	fieldsMethod fieldValidationMethod = iota
 	mappingsMethod
 )
 
 var validationMethods = map[string]fieldValidationMethod{
-	"all":      allMethods,
 	"fields":   fieldsMethod,
 	"mappings": mappingsMethod,
 }
@@ -1632,13 +1630,11 @@ func (r *tester) validateTestScenario(ctx context.Context, result *testrunner.Re
 		return result.WithErrorf("creating fields validator for data stream failed (path: %s): %w", r.dataStreamPath, err)
 	}
 
-	if r.fieldValidationMethod == allMethods || r.fieldValidationMethod == fieldsMethod {
-		if errs := validateFields(scenario.docs, fieldsValidator); len(errs) > 0 {
-			return result.WithError(testrunner.ErrTestCaseFailed{
-				Reason:  fmt.Sprintf("one or more errors found in documents stored in %s data stream", scenario.dataStream),
-				Details: errs.Error(),
-			})
-		}
+	if errs := validateFields(scenario.docs, fieldsValidator); len(errs) > 0 {
+		return result.WithError(testrunner.ErrTestCaseFailed{
+			Reason:  fmt.Sprintf("one or more errors found in documents stored in %s data stream", scenario.dataStream),
+			Details: errs.Error(),
+		})
 	}
 
 	stackVersion, err := semver.NewVersion(r.stackVersion.Number)
@@ -1651,8 +1647,8 @@ func (r *tester) validateTestScenario(ctx context.Context, result *testrunner.Re
 		return result.WithError(err)
 	}
 
-	if r.fieldValidationMethod == allMethods || r.fieldValidationMethod == mappingsMethod {
-		logger.Warn("Validate mappings found (technical preview)")
+	if r.fieldValidationMethod == mappingsMethod {
+		logger.Warn("Validation based on mappings enabled (technical preview)")
 		exceptionFields := listExceptionFields(scenario.docs, fieldsValidator)
 
 		mappingsValidator, err := fields.CreateValidatorForMappings(r.esClient,