documentation, some basic testing

pkg/dom.ts

@@ -1,10 +1,32 @@
 import React from 'react';
 
+/**
+ * Given an JSX element type `TElement`, returns a subset of its props
+ * specified in the union `TProps`.
+ */
 export type PickElementProps<
   TElement extends keyof React.JSX.IntrinsicElements,
   TProps extends keyof React.ComponentProps<TElement>
 > = Pick<React.ComponentProps<TElement>, TProps>;
 
+/**
+ * Given an JSX element type `TElement`, returns its full set of props,
+ * excluding members of the union `TProps`.
+ */
+export type ExcludeElementProps<
+  TElement extends keyof React.JSX.IntrinsicElements,
+  TProps extends keyof React.ComponentProps<TElement>
+> = Exclude<keyof React.ComponentProps<TElement>, TProps>;
+
+export type ElementProps<TElement extends keyof React.JSX.IntrinsicElements> = React.ComponentProps<TElement>;
+
+/**
+ * Mounts a virtual <a> tag and virtually clicks it, intiating a download
+ * on the client's device.
+ *
+ * @param url the URL location of the desired resource
+ * @param filename the name to assign to the download once completed
+ */
 export function clickVirtualDownloadLink(
     url: string,
     filename: string,