Adjust DataTable types.

- Make key in `cell` slot prop less strict to prevent type errors in markup.
- Resolve property path names up to one level deep for header keys.

types/DataTable/DataTable.svelte.d.ts

@@ -1,7 +1,8 @@
 import type { SvelteComponentTyped } from "svelte";
 import type { SvelteHTMLElements } from "svelte/elements";
 
-export type DataTableKey<Row = DataTableRow> = Exclude<keyof Row, "id">;
+export type DataTableKey<Row = DataTableRow> =
+  import("./DataTableTypes.d.ts").PropertyPath<Row>;
 
 export type DataTableValue = any;
 
@@ -37,7 +38,7 @@ export interface DataTableRow {
 export type DataTableRowId = any;
 
 export interface DataTableCell<Row = DataTableRow> {
-  key: DataTableKey<Row>;
+  key: DataTableKey<Row> | (string & {});
   value: DataTableValue;
   display?: (item: Value, row: DataTableRow) => DataTableValue;
 }

types/DataTable/DataTableTypes.d.ts

@@ -0,0 +1,17 @@
+type PathDepth = [never, 0, 1, 2, ...0[]];
+
+type Join<K, P> = K extends string | number
+  ? P extends string | number
+    ? `${K}${"" extends P ? "" : "."}${P}`
+    : never
+  : never;
+
+export type PropertyPath<T, D extends number = 10> = [D] extends [never]
+  ? never
+  : T extends object
+  ? {
+      [K in keyof T]-?: K extends string | number
+        ? `${K}` | Join<K, PropertyPath<T[K], PathDepth[D]>>
+        : never;
+    }[keyof T]
+  : "";