feat(new-tool): json to csv converter

src/tools/json-to-csv/json-to-csv.service.ts

@@ -0,0 +1,35 @@
+export { getHeaders, convertArrayToCsv };
+
+function getHeaders({ array }: { array: Record<string, unknown>[] }): string[] {
+  const headers = new Set<string>();
+
+  array.forEach(item => Object.keys(item).forEach(key => headers.add(key)));
+
+  return Array.from(headers);
+}
+
+function serializeValue(value: unknown): string {
+  if (value === null) {
+    return 'null';
+  }
+
+  if (value === undefined) {
+    return '';
+  }
+
+  const valueAsString = String(value).replace(/\n/g, '\\n').replace(/\r/g, '\\r').replace(/"/g, '\\"');
+
+  if (valueAsString.includes(',')) {
+    return `"${valueAsString}"`;
+  }
+
+  return valueAsString;
+}
+
+function convertArrayToCsv({ array }: { array: Record<string, unknown>[] }): string {
+  const headers = getHeaders({ array });
+
+  const rows = array.map(item => headers.map(header => serializeValue(item[header])));
+
+  return [headers.join(','), ...rows].join('\n');
+}