Add support for minItems and maxItems for repeated (#122)

Author: gauravojha

.golangci.yml

@@ -13,6 +13,7 @@ linters:
     - lll               # don't want hard limits for line length
     - maintidx          # covered by gocyclo
     - mnd               # some unnamed constants are okay
+    - nestif            # covered by gocyclo
     - nilnil
     - nlreturn          # generous whitespace violates house style
     - noinlineerr

internal/gen/jsonschema/buf.protoschema.test.v1.ConstraintTest.jsonschema.strict.bundle.json

@@ -312,6 +312,11 @@ message ConstraintTest {
       }
     }
   }];
+
+  repeated string is_list = 125 [
+    (buf.validate.field).repeated.min_items = 1,
+    (buf.validate.field).repeated.max_items = 10
+  ];
 }
 
 message ConstraintTests {

internal/gen/jsonschema/buf.protoschema.test.v1.ConstraintTest.schema.json

@@ -382,6 +382,14 @@ func (p *Generator) generateField(entry *msgSchema, field protoreflect.FieldDesc
 func (p *Generator) generateFieldValidation(entry *msgSchema, field protoreflect.FieldDescriptor, hasImplicitPresence bool, rules *validate.FieldRules, schema map[string]any) error {
 	if field.IsList() {
 		schema["type"] = jsArray
+		if repeated := rules.GetRepeated(); repeated != nil {
+			if repeated.HasMinItems() {
+				schema["minItems"] = repeated.GetMinItems()
+			}
+			if repeated.HasMaxItems() {
+				schema["maxItems"] = repeated.GetMaxItems()
+			}
+		}
 		items := make(map[string]any)
 		schema["items"] = items
 		schema = items