feat: introduce flag noAdditionalProperties

This will default `additionalProperties` to `false` for all objects in the schema if set to `true`.
The `additionalProperties` annotation, `schemaRoot.additionalProperties` and additionalProperties
set via other ways (nested in `itemProperties`, `patternProperties` or similar) will take
precedence over this setting, so it's fully backwards compatible.

Closes #95.

README.md

@@ -116,6 +116,8 @@ Usage: helm schema [options...] <arguments>
     	Multiple yaml files as inputs (comma-separated)
   -output string
     	Output file path (default "values.schema.json")
+  -noAdditionalProperties value
+         Default additionalProperties to false for all objects in the schema (true/false)
   -schemaRoot.additionalProperties value
     	JSON schema additional properties (true/false)
   -schemaRoot.description string

pkg/cmd.go

@@ -20,6 +20,7 @@ func ParseFlags(progname string, args []string) (*Config, string, error) {
 	flags.StringVar(&conf.OutputPath, "output", "values.schema.json", "Output file path")
 	flags.IntVar(&conf.Draft, "draft", 2020, "Draft version (4, 6, 7, 2019, or 2020)")
 	flags.IntVar(&conf.Indent, "indent", 4, "Indentation spaces (even number)")
+	flags.Var(&conf.NoAdditionalProperties, "noAdditionalProperties", "Default additionalProperties to false for all objects in the schema")
 
 	// Nested SchemaRoot flags
 	flags.StringVar(&conf.SchemaRoot.ID, "schemaRoot.id", "", "JSON schema ID")
@@ -88,6 +89,10 @@ func MergeConfig(fileConfig, flagConfig *Config) *Config {
 	if flagConfig.IndentSet || mergedConfig.Indent == 0 {
 		mergedConfig.Indent = flagConfig.Indent
 	}
+
+	if flagConfig.NoAdditionalProperties.IsSet() {
+		mergedConfig.NoAdditionalProperties = flagConfig.NoAdditionalProperties
+	}
 	if flagConfig.SchemaRoot.ID != "" {
 		mergedConfig.SchemaRoot.ID = flagConfig.SchemaRoot.ID
 	}

pkg/generator.go

@@ -89,14 +89,16 @@ func GenerateJsonSchema(config *Config) error {
 	}
 
 	// Convert merged Schema into a JSON Schema compliant map
-	jsonSchemaMap, err := convertSchemaToMap(mergedSchema)
+	jsonSchemaMap, err := convertSchemaToMap(mergedSchema, config.NoAdditionalProperties.value)
 	if err != nil {
 		return err
 	}
 	jsonSchemaMap["$schema"] = schemaURL // Include the schema draft version
 
 	if config.SchemaRoot.AdditionalProperties.IsSet() {
 		jsonSchemaMap["additionalProperties"] = config.SchemaRoot.AdditionalProperties.Value()
+	} else if config.NoAdditionalProperties.value {
+		jsonSchemaMap["additionalProperties"] = false
 	}
 
 	// If validation is successful, marshal the schema and save to the file

pkg/generator_test.go

@@ -11,41 +11,68 @@ import (
 )
 
 func TestGenerateJsonSchema(t *testing.T) {
-	config := &Config{
-		Input: []string{
-			"../testdata/full.yaml",
-			"../testdata/empty.yaml",
+	tests := []struct {
+		name               string
+		config             *Config
+		templateSchemaFile string
+	}{
+		{
+			name: "full json schema",
+			config: &Config{
+				Input: []string{
+					"../testdata/full.yaml",
+					"../testdata/empty.yaml",
+				},
+				OutputPath: "../testdata/output.json",
+				Draft:      2020,
+				Indent:     4,
+				SchemaRoot: SchemaRoot{
+					ID:                   "https://example.com/schema",
+					Ref:                  "schema/product.json",
+					Title:                "Helm Values Schema",
+					Description:          "Schema for Helm values",
+					AdditionalProperties: BoolFlag{set: true, value: true},
+				},
+			},
+			templateSchemaFile: "../testdata/full.schema.json",
 		},
-		OutputPath: "../testdata/output.json",
-		Draft:      2020,
-		Indent:     4,
-		SchemaRoot: SchemaRoot{
-			ID:                   "https://example.com/schema",
-			Ref:                  "schema/product.json",
-			Title:                "Helm Values Schema",
-			Description:          "Schema for Helm values",
-			AdditionalProperties: BoolFlag{set: true, value: true},
+		{
+			name: "full json schema",
+			config: &Config{
+				Draft:                  2020,
+				Indent:                 4,
+				NoAdditionalProperties: BoolFlag{set: true, value: true},
+				Input: []string{
+					"../testdata/noAdditionalProperties.yaml",
+				},
+				OutputPath: "../testdata/output1.json",
+			},
+			templateSchemaFile: "../testdata/noAdditionalProperties.schema.json",
 		},
 	}
 
-	err := GenerateJsonSchema(config)
-	assert.NoError(t, err)
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			err := GenerateJsonSchema(tt.config)
+			assert.NoError(t, err)
 
-	generatedBytes, err := os.ReadFile(config.OutputPath)
-	assert.NoError(t, err)
+			generatedBytes, err := os.ReadFile(tt.config.OutputPath)
+			assert.NoError(t, err)
 
-	templateBytes, err := os.ReadFile("../testdata/full.schema.json")
-	assert.NoError(t, err)
+			templateBytes, err := os.ReadFile(tt.templateSchemaFile)
+			assert.NoError(t, err)
 
-	var generatedSchema, templateSchema map[string]interface{}
-	err = json.Unmarshal(generatedBytes, &generatedSchema)
-	assert.NoError(t, err)
-	err = json.Unmarshal(templateBytes, &templateSchema)
-	assert.NoError(t, err)
+			var generatedSchema, templateSchema map[string]interface{}
+			err = json.Unmarshal(generatedBytes, &generatedSchema)
+			assert.NoError(t, err)
+			err = json.Unmarshal(templateBytes, &templateSchema)
+			assert.NoError(t, err)
 
-	assert.Equal(t, templateSchema, generatedSchema, "Generated JSON schema does not match the template")
+			assert.Equal(t, templateSchema, generatedSchema, "Generated JSON schema does not match the template")
 
-	os.Remove(config.OutputPath)
+			os.Remove(tt.config.OutputPath)
+		})
+	}
 }
 
 func TestGenerateJsonSchema_Errors(t *testing.T) {
@@ -149,6 +176,7 @@ func TestGenerateJsonSchema_AdditionalProperties(t *testing.T) {
 		name                    string
 		additionalPropertiesSet bool
 		additionalProperties    bool
+		noAdditionalProperties  bool
 		expected                interface{}
 	}{
 		{
@@ -168,22 +196,42 @@ func TestGenerateJsonSchema_AdditionalProperties(t *testing.T) {
 			additionalPropertiesSet: false,
 			expected:                nil,
 		},
+		{
+			name:                    "AdditionalProperties not set, but NoAdditionalProperties set",
+			additionalPropertiesSet: false,
+			noAdditionalProperties:  true,
+			expected:                false,
+		},
+		{
+			name:                    "NoAdditionalProperties set, but AdditionalProperties set to true",
+			additionalPropertiesSet: true,
+			additionalProperties:    true,
+			noAdditionalProperties:  true,
+			expected:                true,
+		},
 	}
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
 			additionalPropertiesFlag := &BoolFlag{}
+			noAdditionalPropertiesFlag := &BoolFlag{}
 			if tt.additionalPropertiesSet {
 				if err := additionalPropertiesFlag.Set(fmt.Sprintf("%t", tt.additionalProperties)); err != nil {
 					t.Fatalf("Failed to set additionalPropertiesFlag: %v", err)
 				}
 			}
+			if tt.noAdditionalProperties {
+				if err := noAdditionalPropertiesFlag.Set(fmt.Sprintf("%t", tt.noAdditionalProperties)); err != nil {
+					t.Fatalf("Failed to set noAdditionalPropertiesFlag: %v", err)
+				}
+			}
 
 			config := &Config{
-				Input:      []string{"../testdata/empty.yaml"},
-				OutputPath: "../testdata/empty.schema.json",
-				Draft:      2020,
-				Indent:     4,
+				Input:                  []string{"../testdata/empty.yaml"},
+				OutputPath:             "../testdata/empty.schema.json",
+				Draft:                  2020,
+				Indent:                 4,
+				NoAdditionalProperties: *noAdditionalPropertiesFlag,
 				SchemaRoot: SchemaRoot{
 					ID:                   "",
 					Title:                "",

pkg/parser.go

@@ -103,11 +103,11 @@ func mergeSchemas(dest, src *Schema) *Schema {
 	return dest
 }
 
-func convertSchemaToMap(schema *Schema) (map[string]interface{}, error) {
-	return convertSchemaToMapRec(schema, make(map[uintptr]bool))
+func convertSchemaToMap(schema *Schema, noAdditionalProperties bool) (map[string]interface{}, error) {
+	return convertSchemaToMapRec(schema, make(map[uintptr]bool), noAdditionalProperties)
 }
 
-func convertSchemaToMapRec(schema *Schema, visited map[uintptr]bool) (map[string]interface{}, error) {
+func convertSchemaToMapRec(schema *Schema, visited map[uintptr]bool, noAdditionalProperties bool) (map[string]interface{}, error) {
 	if schema == nil {
 		return nil, nil
 	}
@@ -161,9 +161,6 @@ func convertSchemaToMapRec(schema *Schema, visited map[uintptr]bool) (map[string
 	if schema.MinProperties != nil {
 		schemaMap["minProperties"] = *schema.MinProperties
 	}
-	if schema.PatternProperties != nil {
-		schemaMap["patternProperties"] = schema.PatternProperties
-	}
 	if schema.Title != "" {
 		schemaMap["title"] = schema.Title
 	}
@@ -178,6 +175,8 @@ func convertSchemaToMapRec(schema *Schema, visited map[uintptr]bool) (map[string
 	}
 	if schema.AdditionalProperties != nil {
 		schemaMap["additionalProperties"] = *schema.AdditionalProperties
+	} else if noAdditionalProperties && schema.Type == "object" {
+		schemaMap["additionalProperties"] = false
 	}
 	if schema.ID != "" {
 		schemaMap["$id"] = schema.ID
@@ -196,7 +195,7 @@ func convertSchemaToMapRec(schema *Schema, visited map[uintptr]bool) (map[string
 
 	// Nested Schemas
 	if schema.Items != nil {
-		itemsMap, err := convertSchemaToMapRec(schema.Items, visited)
+		itemsMap, err := convertSchemaToMapRec(schema.Items, visited, noAdditionalProperties)
 		if err != nil {
 			return nil, err
 		}
@@ -205,7 +204,7 @@ func convertSchemaToMapRec(schema *Schema, visited map[uintptr]bool) (map[string
 	if schema.Properties != nil {
 		propertiesMap := make(map[string]interface{})
 		for propName, propSchema := range schema.Properties {
-			propMap, err := convertSchemaToMapRec(propSchema, visited)
+			propMap, err := convertSchemaToMapRec(propSchema, visited, noAdditionalProperties)
 			if err != nil {
 				return nil, err
 			}
@@ -214,6 +213,18 @@ func convertSchemaToMapRec(schema *Schema, visited map[uintptr]bool) (map[string
 		schemaMap["properties"] = propertiesMap
 	}
 
+	if schema.PatternProperties != nil {
+		patternPropertiesMap := make(map[string]interface{})
+		for propName, propSchema := range schema.PatternProperties {
+			propMap, err := convertSchemaToMapRec(propSchema, visited, noAdditionalProperties)
+			if err != nil {
+				return nil, err
+			}
+			patternPropertiesMap[propName] = propMap
+		}
+		schemaMap["patternProperties"] = patternPropertiesMap
+	}
+
 	delete(visited, ptr)
 
 	return schemaMap, nil

pkg/parser_test.go

@@ -271,7 +271,7 @@ func TestConvertSchemaToMap(t *testing.T) {
 
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			got, err := convertSchemaToMap(tt.schema)
+			got, err := convertSchemaToMap(tt.schema, false)
 			if (err != nil) != tt.wantErr {
 				t.Errorf("convertSchemaToMap() error = %v, wantErr %v", err, tt.wantErr)
 				return
@@ -318,7 +318,7 @@ func TestConvertSchemaToMapFail(t *testing.T) {
 
 	for _, tc := range tests {
 		t.Run(tc.name, func(t *testing.T) {
-			_, err := convertSchemaToMap(tc.schema)
+			_, err := convertSchemaToMap(tc.schema, false)
 			tc.expectedErr(t, err)
 		})
 	}

pkg/schema.go

@@ -23,7 +23,7 @@ type Schema struct {
 	UniqueItems          bool               `json:"uniqueItems,omitempty"`
 	MaxProperties        *uint64            `json:"maxProperties,omitempty"`
 	MinProperties        *uint64            `json:"minProperties,omitempty"`
-	PatternProperties    interface{}        `json:"patternProperties,omitempty"`
+	PatternProperties    map[string]*Schema `json:"patternProperties,omitempty"`
 	Required             []string           `json:"required,omitempty"`
 	Items                *Schema            `json:"items,omitempty"`
 	ItemsEnum            []any              `json:"itemsEnum,omitempty"`
@@ -170,7 +170,7 @@ func processComment(schema *Schema, comment string) (isRequired bool, isHidden b
 					schema.MinProperties = &v
 				}
 			case "patternProperties":
-				var jsonObject interface{}
+				var jsonObject map[string]*Schema
 				if err := json.Unmarshal([]byte(value), &jsonObject); err == nil {
 					schema.PatternProperties = jsonObject
 				}

pkg/utils.go

@@ -17,10 +17,11 @@ type SchemaRoot struct {
 
 // Save values of parsed flags in Config
 type Config struct {
-	Input      multiStringFlag `yaml:"input"`
-	OutputPath string          `yaml:"output"`
-	Draft      int             `yaml:"draft"`
-	Indent     int             `yaml:"indent"`
+	Input                  multiStringFlag `yaml:"input"`
+	OutputPath             string          `yaml:"output"`
+	Draft                  int             `yaml:"draft"`
+	Indent                 int             `yaml:"indent"`
+	NoAdditionalProperties BoolFlag        `yaml:"noAdditionalProperties"`
 
 	SchemaRoot SchemaRoot `yaml:"schemaRoot"`
 

testdata/noAdditionalProperties.schema.json

@@ -0,0 +1,39 @@
+{
+    "$schema": "https://json-schema.org/draft/2020-12/schema",
+    "additionalProperties": false,
+    "properties": {
+        "object": {
+            "additionalProperties": false,
+            "properties": {},
+            "type": "object"
+        },
+        "objectOfObjects": {
+            "additionalProperties": false,
+            "patternProperties": {
+                "^.*$": {
+                    "additionalProperties": false,
+                    "type": "object"
+                }
+            },
+            "properties": {},
+            "type": "object"
+        },
+        "objectOfObjectsWithInnerAdditionalPropertiesAllowed": {
+            "additionalProperties": false,
+            "patternProperties": {
+                "^.*$": {
+                    "additionalProperties": true,
+                    "type": "object"
+                }
+            },
+            "properties": {},
+            "type": "object"
+        },
+        "objectWithAdditionalPropertiesAllowed": {
+            "additionalProperties": true,
+            "properties": {},
+            "type": "object"
+        }
+    },
+    "type": "object"
+}

testdata/noAdditionalProperties.yaml

@@ -0,0 +1,4 @@
+object: {}
+objectWithAdditionalPropertiesAllowed: {} # @schema additionalProperties: true
+objectOfObjects: {} # @schema patternProperties: { "^.*$": {"type": "object" } }
+objectOfObjectsWithInnerAdditionalPropertiesAllowed: {} # @schema patternProperties: { "^.*$": {"type": "object", "additionalProperties": true }}