Add Warn for omitempty

Author: JoelSpeed

pkg/analysis/optionalfields/analyzer.go

@@ -127,11 +127,10 @@ func (a *analyzer) checkField(pass *analysis.Pass, field *ast.Field, markersAcce
 // (such as to be able to marshal an empty object with all possible options shown)
 // and when this is desired, there is an option to ignore the omitempty tag.
 func (a *analyzer) checkFieldOmitEmpty(pass *analysis.Pass, field *ast.Field, fieldName string, jsonTags extractjsontags.FieldTagInfo) {
-	if a.omitEmptyPolicy == config.OptionalFieldsOmitEmptyPolicyIgnore {
-		return
-	}
-
-	if !jsonTags.OmitEmpty {
+	switch {
+	case jsonTags.OmitEmpty, a.omitEmptyPolicy == config.OptionalFieldsOmitEmptyPolicyIgnore:
+		// Nothing to do, either we have omitempty, or we are ignoring it.
+	case a.omitEmptyPolicy == config.OptionalFieldsOmitEmptyPolicySuggestFix:
 		pass.Report(analysis.Diagnostic{
 			Pos:     field.Pos(),
 			Message: fmt.Sprintf("field %s is optional and should be omitempty", fieldName),
@@ -147,6 +146,8 @@ func (a *analyzer) checkFieldOmitEmpty(pass *analysis.Pass, field *ast.Field, fi
 				},
 			},
 		})
+	case a.omitEmptyPolicy == config.OptionalFieldsOmitEmptyPolicyWarn:
+		pass.Reportf(field.Pos(), "field %s is optional and should be omitempty", fieldName)
 	}
 }
 

pkg/config/linters_config.go

@@ -181,6 +181,7 @@ type OptionalFieldsOmitEmpty struct {
 	// policy determines whether the linter should require omitempty for all optional fields.
 	// Valid values are "SuggestFix" and "Ignore".
 	// When set to "SuggestFix", the linter will suggest adding the `omitempty` tag when an optional field does not have it.
+	// When set to "Warn", the linter will emit a warning if the field does not have the `omitempty` tag.
 	// When set to "Ignore", and optional field missing the `omitempty` tag will be ignored.
 	// Note, when set to "Ignore", and a field does not have the `omitempty` tag, this may affect whether the field should be a pointer or not.
 	Policy OptionalFieldsOmitEmptyPolicy `json:"policy"`
@@ -215,6 +216,9 @@ const (
 	// OptionalFieldsOmitEmptyPolicySuggestFix indicates that the linter will emit a warning if the field does not have omitempty, and suggest a fix.
 	OptionalFieldsOmitEmptyPolicySuggestFix OptionalFieldsOmitEmptyPolicy = "SuggestFix"
 
+	// OptionalFieldsOmitEmptyPolicyWarn indicates that the linter will emit a warning if the field does not have omitempty.
+	OptionalFieldsOmitEmptyPolicyWarn OptionalFieldsOmitEmptyPolicy = "Warn"
+
 	// OptionalFieldsOmitEmptyPolicyIgnore indicates that the linter will ignore any field missing the omitempty tag.
 	OptionalFieldsOmitEmptyPolicyIgnore OptionalFieldsOmitEmptyPolicy = "Ignore"
 )

pkg/validation/linters_config.go

@@ -126,9 +126,9 @@ func validateOptionFieldsOmitEmpty(oec config.OptionalFieldsOmitEmpty, fldPath *
 	fieldErrors := field.ErrorList{}
 
 	switch oec.Policy {
-	case "", config.OptionalFieldsOmitEmptyPolicyIgnore, config.OptionalFieldsOmitEmptyPolicySuggestFix:
+	case "", config.OptionalFieldsOmitEmptyPolicyIgnore, config.OptionalFieldsOmitEmptyPolicyWarn, config.OptionalFieldsOmitEmptyPolicySuggestFix:
 	default:
-		fieldErrors = append(fieldErrors, field.Invalid(fldPath.Child("policy"), oec.Policy, fmt.Sprintf("invalid value, must be one of %q, %q or omitted", config.OptionalFieldsOmitEmptyPolicyIgnore, config.OptionalFieldsOmitEmptyPolicySuggestFix)))
+		fieldErrors = append(fieldErrors, field.Invalid(fldPath.Child("policy"), oec.Policy, fmt.Sprintf("invalid value, must be one of %q, %q, %q or omitted", config.OptionalFieldsOmitEmptyPolicyIgnore, config.OptionalFieldsOmitEmptyPolicyWarn, config.OptionalFieldsOmitEmptyPolicySuggestFix)))
 	}
 
 	return fieldErrors