Update required validator in Field to correctly handle falsey values (#…

…2499)

Previously, the validator incorrectly returned errors for all falsey
values, e.g. the number `0`.
Now, it only returns an error for `undefined`, `null`, `false` and empty
strings.

.changeset/quiet-bats-mate.md

@@ -0,0 +1,8 @@
+---
+"@comet/admin": patch
+---
+
+Update required validator in `Field` to correctly handle falsey values
+
+Previously, the validator incorrectly returned errors for all falsey values, e.g. the number `0`.
+Now, it only returns an error for `undefined`, `null`, `false` and empty strings.

packages/admin/admin/src/form/Field.tsx

@@ -6,7 +6,12 @@ import { FormattedMessage } from "react-intl";
 import { FieldContainer, FieldContainerProps } from "./FieldContainer";
 import { useFinalFormContext } from "./FinalFormContextProvider";
 
-const requiredValidator = (value: any) => (value ? undefined : <FormattedMessage id="comet.form.required" defaultMessage="Required" />);
+const requiredValidator = (value: any) => {
+    if (value === undefined || value === null || value === false || value === "") {
+        return <FormattedMessage id="comet.form.required" defaultMessage="Required" />;
+    }
+    return undefined;
+};
 
 const composeValidators =
     (...validators: Array<(value: any, allValues: object) => any>) =>