yup: add snake case to ObjectSchema (#43708)

* yup: add snake case

* remove auto formatting

types/yup/index.d.ts

@@ -257,6 +257,7 @@ export interface ObjectSchema<T extends object | null | undefined = object> exte
     noUnknown(onlyKnownKeys?: boolean, message?: ObjectLocale['noUnknown']): ObjectSchema<T>;
     transformKeys(callback: (key: any) => any): void;
     camelCase(): ObjectSchema<T>;
+    snakeCase(): ObjectSchema<T>;
     constantCase(): ObjectSchema<T>;
     nullable(isNullable?: true): ObjectSchema<T | null>;
     nullable(isNullable: false): ObjectSchema<Exclude<T, null>>;

types/yup/yup-tests.ts

@@ -458,6 +458,7 @@ objSchema.noUnknown(true, 'message');
 objSchema.noUnknown(true, () => 'message');
 objSchema.transformKeys(key => key.toUpperCase());
 objSchema.camelCase();
+objSchema.snakeCase();
 objSchema.constantCase();
 
 const description: SchemaDescription = {