add csv converter

core/static/bundled/utils/csv.ts

@@ -0,0 +1,43 @@
+import type { NestedKeyOf } from "#core:utils/types";
+
+interface StringifyOptions<T extends object> {
+  /** The columns to include in the resulting CSV. */
+  columns: readonly NestedKeyOf<T>[];
+  /** Content of the first row */
+  titleRow?: readonly string[];
+}
+
+function getNested<T extends object>(obj: T, key: NestedKeyOf<T>) {
+  const path: (keyof object)[] = key.split(".") as (keyof unknown)[];
+  let res = obj[path.shift() as keyof T];
+  for (const node of path) {
+    if (res === null) {
+      break;
+    }
+    res = res[node];
+  }
+  return res;
+}
+
+export const csv = {
+  stringify: <T extends object>(objs: T[], options?: StringifyOptions<T>) => {
+    const columns = options.columns;
+    const content = objs
+      .map((obj) => {
+        return columns
+          .map((col) => {
+            return (getNested(obj, col) ?? "")
+              .toString()
+              .replace(/,/g, ",")
+              .replace(/\n/g, " ");
+          })
+          .join(",");
+      })
+      .join("\n");
+    if (!options.titleRow) {
+      return content;
+    }
+    const firstRow = options.titleRow.map((s) => s.replace(/,/g, ",")).join(",");
+    return `${firstRow}\n${content}`;
+  },
+};