Add support for Joi.any().cast() to string and number types

README.md

@@ -212,6 +212,7 @@ export interface Settings {
 - .allow(null) - will add as an optional type eg `string | null`
 - .unknown(true) - will add a property `[x: string]: unknown;`
 - .example() - jsdoc
+- .cast() - currently will honor casting to string and number types, map and set to be added later
   Any many others
 
 ## Contributing

src/__tests__/cast/cast.ts

@@ -0,0 +1,45 @@
+import { existsSync, readFileSync, rmdirSync } from 'fs';
+
+import { convertFromDirectory } from '../../index';
+
+describe('Cast primitive types', () => {
+  const typeOutputDirectory = './src/__tests__/cast/interfaces';
+
+  beforeAll(() => {
+    if (existsSync(typeOutputDirectory)) {
+      rmdirSync(typeOutputDirectory, { recursive: true });
+    }
+  });
+
+  test('casts all variations from file', async () => {
+    const result = await convertFromDirectory({
+      schemaDirectory: './src/__tests__/cast/schemas',
+      typeOutputDirectory
+    });
+
+    expect(result).toBe(true);
+
+    const oneContent = readFileSync(`${typeOutputDirectory}/One.ts`).toString();
+
+    expect(oneContent).toBe(
+      `/**
+ * This file was automatically generated by joi-to-typescript
+ * Do not modify this file manually
+ */
+
+export type NumberType = number;
+
+export interface Numbers {
+  bool: number;
+  day: number;
+}
+
+export type StringType = string;
+
+export interface Strings {
+  num: string;
+}
+`
+    );
+  });
+});

src/__tests__/cast/schemas/OneSchema.ts

@@ -0,0 +1,14 @@
+import Joi from 'joi';
+
+export const NumberSchema = Joi.object({
+  bool: Joi.boolean().cast('number').required(),
+  day: Joi.date().cast('number').required(),
+}).meta({ className: 'Numbers' });
+
+export const StringSchema = Joi.object({
+  num: Joi.number().cast('string').required()
+}).meta({ className: 'Strings' })
+
+export const StringType = Joi.number().cast('string')
+
+export const NumberType = Joi.boolean().cast('number')

src/index.ts

@@ -29,7 +29,8 @@ function defaultSettings(settings: Partial<Settings>): Settings {
       sortPropertiesByName: true,
       commentEverything: false,
       ignoreFiles: [],
-      indentationChacters: '  '
+      indentationChacters: '  ',
+      honorCastTo: [],
     },
     settings
   ) as Settings;

src/joiDescribeTypes.ts

@@ -29,6 +29,10 @@ export interface BaseDescribe extends Joi.Description {
      * https://joi.dev/api/#objectunknownallow
      */
     unknown?: boolean;
+    /**
+     * https://joi.dev/api/?v=17.4.2#anycastto
+     */
+    cast?: 'string' | 'number' | 'map' | 'set';
   };
   metas?: Meta[];
 }

src/parse.ts

@@ -14,6 +14,10 @@ import { getInterfaceOrTypeName, getMetadataFromDetails } from './joiUtils';
 // see __tests__/joiTypes.ts for more information
 export const supportedJoiTypes = ['array', 'object', 'alternatives', 'any', 'boolean', 'date', 'number', 'string'];
 
+// @TODO - Temporarily used prevent 'map' and 'set' from being used by cast
+//         Remove once support for 'map' and 'set' is added
+const validCastTo = ['string', 'number'];
+
 function getCommonDetails(
   details: Describe,
   settings: Settings
@@ -184,6 +188,13 @@ export function parseSchema(
   rootSchema?: boolean
 ): TypeContent | undefined {
   function parseHelper(): TypeContent | undefined {
+    // Convert type if a valid cast type is present
+    if (details.flags?.cast && validCastTo.includes(details.flags?.cast as ('number' | 'string'))) {
+      // @NOTE - if additional values are added beyond 'string' and 'number' further transformation will
+      // be needed on the details object to support those types
+      details.type = details.flags?.cast as ('string' | 'number');
+    }
+
     switch (details.type) {
       case 'array':
         return parseArray(details, settings);