Add support for additionalProperties.

__tests__/additionalProperties.ts

@@ -0,0 +1,80 @@
+// tslint:disable:no-submodule-imports
+import { IsString, MinLength, ValidateNested } from 'class-validator'
+import { validationMetadatasToSchemas } from '../src'
+import { Type } from 'class-transformer'
+import { defaultMetadataStorage } from 'class-transformer/storage'
+
+class User {
+  @IsString()
+  name: string;
+}
+
+// @ts-ignore: not referenced
+class Post {
+  // @ts-ignore
+  @ValidateNested({each: true})
+  // @Matches(/w{10}/, {each: true})
+  @Type(() => {
+    return String
+  })
+  @MinLength(2, {each: true})
+    // users: User[]
+  userStatus: Map<string, string>
+}
+
+// @ts-ignore: not referenced
+class PostWidthUsers {
+  @ValidateNested({each: true})
+  @Type(() => User)
+  users: Map<string, User>
+}
+
+describe('classValidatorConverter', () => {
+  it('combines converted class-validator metadata into JSON Schemas', async () => {
+    const schemas = validationMetadatasToSchemas({
+      classTransformerMetadataStorage: defaultMetadataStorage,
+    })
+    expect(schemas).toEqual({
+      "User": {
+        "properties": {
+          "name": {
+            "type": "string"
+          }
+        },
+        "type": "object",
+        "required": [
+          "name"
+        ]
+      },
+      "Post": {
+        "properties": {
+          "userStatus": {
+            "additionalProperties": {
+              "minLength": 2,
+              "type": "string"
+            },
+            "type": "object"
+          }
+        },
+        "type": "object",
+        "required": [
+          "userStatus"
+        ]
+      },
+      "PostWidthUsers": {
+        "properties": {
+          "users": {
+            "additionalProperties": {
+              "$ref": "#/definitions/User"
+            },
+            "type": "object"
+          }
+        },
+        "type": "object",
+        "required": [
+          "users"
+        ]
+      }
+    })
+  })
+})

src/index.ts

@@ -114,12 +114,33 @@ function applyConverters(
   options: IOptions
 ): SchemaObject {
   const converters = { ...defaultConverters, ...options.additionalConverters }
+
   const convert = (meta: ValidationMetadata) => {
+    // @ts-ignore
+    const typeMeta = options.classTransformerMetadataStorage
+      ? options.classTransformerMetadataStorage.findTypeMetadata(
+        // @ts-ignore
+        meta.target,
+        meta.propertyName
+      )
+      : null
+    const isMap = typeMeta ? new typeMeta.reflectedType() instanceof Map : false;
+
     const converter =
       converters[meta.type] || converters[cv.ValidationTypes.CUSTOM_VALIDATION]
 
     const items = _.isFunction(converter) ? converter(meta, options) : converter
-    return meta.each ? { items, type: 'array' } : items
+
+    if (meta.each && isMap) {
+      // @ts-ignore
+      return {
+        additionalProperties: {
+          ...items,
+        },
+        type: "object"
+      };
+    }
+    return meta.each ? {items, type: "array"} : items;
   }
 
   // @ts-ignore: array spread