feat: add a couple type helpers

Author: airjp73

TODO.md

@@ -1,5 +1,3 @@
-- Consider adding a `beforeSubmit` callback
-
 // follows
 
 - Globally setting some settings with a context or something.

packages/core/src/index.ts

@@ -10,3 +10,4 @@ export * from "./createValidator";
 export * from "./native-form-data/flatten";
 export * from "./constants";
 export * from "./input-types";
+export * from "./type-helpers";

packages/core/src/type-helpers.test.ts

@@ -0,0 +1,10 @@
+import { FormScope } from "../dist";
+import { FieldValue } from "./type-helpers";
+
+describe("FieldValue", () => {
+  it("should work with a single field", () => {
+    type TestForm = FormScope<{ foo: string }>;
+    type Foo = FieldValue<TestForm, "foo">;
+    expectTypeOf<Foo>().toEqualTypeOf<string>();
+  });
+});

packages/core/src/type-helpers.tsx

@@ -0,0 +1,9 @@
+import { StringToPathTuple, ValidStringPaths, ValueAtPath } from "@rvf/set-get";
+import { FormScope } from "./form";
+
+export type ScopedValues<Scope> = Scope extends FormScope<infer U> ? U : never;
+
+export type FieldValue<
+  Scope,
+  Path extends ValidStringPaths<ScopedValues<Scope>>,
+> = ValueAtPath<ScopedValues<Scope>, StringToPathTuple<Path>>;

packages/react/src/index.ts

@@ -23,6 +23,8 @@ export {
   type NumberInputValue,
   type NativeValueByType,
   type ValueOfInputType,
+  type ScopedValues,
+  type FieldValue,
 } from "@rvf/core";
 export { type FormApi, type FormFields } from "./base";
 export { useForm, FormOpts } from "./useForm";

packages/remix/src/index.ts

@@ -48,6 +48,8 @@ export {
   type GetInputProps,
   type GetInputPropsParam,
   type MinimalInputProps,
+  type ScopedValues,
+  type FieldValue,
 } from "@rvf/react";
 export { useForm, type RemixFormOpts as FormScopeRemixOpts } from "./useForm";
 export { ValidatedForm, type ValidatedFormProps } from "./ValidatedForm";