feat: support for omitzero added in Go 1.24

fixes #471

Author: perher

pkg/generator/config.go

@@ -42,6 +42,8 @@ type Config struct {
 	DisableCustomTypesForMaps bool
 	// AliasSingleAllOfAnyOfRefs will convert types with a single nested anyOf or allOf ref type into a type alias.
 	AliasSingleAllOfAnyOfRefs bool
+	// PreferOmitzero will use omit omitzero instead of omitempty, note this requires Go 1.24
+	PreferOmitzero bool
 }
 
 type SchemaMapping struct {

pkg/generator/schema_generator.go

@@ -803,11 +803,16 @@ func (g *schemaGenerator) addStructField(
 
 	tags := ""
 
-	if isRequired || g.DisableOmitempty() {
+	switch {
+	case isRequired || g.DisableOmitempty():
 		for _, tag := range g.config.Tags {
 			tags += fmt.Sprintf(`%s:"%s" `, tag, name)
 		}
-	} else {
+	case g.config.PreferOmitzero:
+		for _, tag := range g.config.Tags {
+			tags += fmt.Sprintf(`%s:"%s,omitzero" `, tag, name)
+		}
+	default:
 		for _, tag := range g.config.Tags {
 			tags += fmt.Sprintf(`%s:"%s,omitempty" `, tag, name)
 		}

tests/data/preferOmitzero/preferOmitzero.go

@@ -0,0 +1,49 @@
+{
+  "$schema": "http://json-schema.org/draft-04/schema#",
+  "id": "https://example.com/primitives",
+  "type": "object",
+  "properties": {
+    "myString": {
+      "type": "string"
+    },
+    "myNumber": {
+      "type": "number"
+    },
+    "myInteger": {
+      "type": "integer"
+    },
+    "myBoolean": {
+      "type": "boolean"
+    },
+    "myNull": {
+      "type": "null"
+    },
+    "myStringArray": {
+      "type": "array",
+      "items": {
+        "type": "string"
+      }
+    },
+    "myNullArray": {
+      "type": "array",
+      "items": {
+        "type": "null"
+      }
+    },
+    "myObjectArray": {
+      "type": "array",
+      "items": {
+        "type": "object"
+      }
+    },
+    "myArray": {
+      "type": "array"
+    },
+    "myMap": {
+      "type": "object",
+      "additionalProperties": {
+        "type": "number"
+      }
+    }
+  }
+}

tests/data/preferOmitzero/preferOmitzero.json

@@ -235,6 +235,16 @@ func TestAliasSingleAllOfAnyOfRefs(t *testing.T) {
 	testExamples(t, cfg, "./data/aliasSingleAllOfAnyOfRefs")
 }
 
+func TestPreferOmitzero(t *testing.T) {
+	t.Parallel()
+
+	cfg := basicConfig
+	cfg.PreferOmitzero = true
+	cfg.Tags = []string{"json"}
+
+	testExamples(t, cfg, "./data/preferOmitzero")
+}
+
 func TestSchemaExtensions(t *testing.T) {
 	t.Parallel()