feat: Support minItems and maxItems

README.md

@@ -145,6 +145,8 @@ foo: bar
 | [`$ref`](#ref) | Accepts an URI to a valid `jsonschema`. Extend the schema for the current key | Takes an URI (or relative file) |
 | [`minLength`](#minlength) | Minimum string length. | Takes an `integer`. Must be smaller or equal than `maxLength` (if used) |
 | [`maxLength`](#maxlength) | Maximum string length. | Takes an `integer`. Must be greater or equal than `minLength` (if used) |
+| [`minItems`](#minItems) | Minimum length of an array. | Takes an `integer`. Must be smaller or equal than `maxItems` (if used) |
+| [`maxItems`](#maxItems) | Maximum length of an array. | Takes an `integer`. Must be greater or equal than `minItems` (if used) |
 
 ## Validation & completion
 
@@ -716,6 +718,31 @@ The value must be an integer greater than zero and defines the maximum length of
 namespace: foo
 ```
 
+#### `minItems`
+
+The value must be an integer greater than zero and defines the minimum length of an array value.
+
+```yaml
+# @schema
+# minItems: 1
+# @schema
+namespace:
+  - foo
+```
+
+#### `maxItems`
+
+The value must be an integer greater than zero and defines the maximum length of an array value.
+
+```yaml
+# @schema
+# maxItems: 2
+# @schema
+namespace:
+  - foo
+  - bar
+```
+
 #### `$ref`
 
 The value must be an URI or relative file.

pkg/schema/schema.go

@@ -247,6 +247,8 @@ type Schema struct {
 	CustomAnnotations    map[string]interface{} `yaml:"-"                              json:",omitempty"`
 	MinLength            *int                   `yaml:"minLength,omitempty"              json:"minLength,omitempty"`
 	MaxLength            *int                   `yaml:"maxLength,omitempty"              json:"maxLength,omitempty"`
+	MinItems             *int                   `yaml:"minItems,omitempty"              json:"minItems,omitempty"`
+	MaxItems             *int                   `yaml:"maxItems,omitempty"              json:"maxItems,omitempty"`
 }
 
 func NewSchema(schemaType string) *Schema {
@@ -413,6 +415,14 @@ func (s Schema) Validate() error {
 		return fmt.Errorf("cant use items if type is %s. Use type=array", s.Type)
 	}
 
+	if (s.MinItems != nil || s.MaxItems != nil) && !s.Type.IsEmpty() && !s.Type.Matches("array") {
+		return fmt.Errorf("cant use minItems or maxItems if type is %s. Use type=array", s.Type)
+	}
+
+	if (s.MinItems != nil && s.MaxItems != nil) && *s.MaxItems < *s.MinItems {
+		return errors.New("minItems cant be greater than maxItems")
+	}
+
 	if s.Const != nil && !s.Type.IsEmpty() {
 		return errors.New("if your are using const, you can't use type")
 	}

pkg/schema/schema_test.go

@@ -147,6 +147,30 @@ func TestValidate(t *testing.T) {
 # @schema`,
 			expectedValid: true,
 		},
+		{
+			comment: `
+# @schema
+# minItems: 1
+# maxItems: 2
+# @schema`,
+			expectedValid: true,
+		},
+		{
+			comment: `
+# @schema
+# minItems: 2
+# maxItems: 1
+# @schema`,
+			expectedValid: false,
+		},
+		{
+			comment: `
+# @schema
+# type: string
+# minItems: 1
+# @schema`,
+			expectedValid: false,
+		},
 	}
 
 	for _, test := range tests {