Add filesExist

1 files changed, 28 insertions, 0 deletions

diff --git a/webAO/utils/filesExist.ts b/webAO/utils/filesExist.ts
new file mode 100644
index 0000000..2f39427
--- /dev/null
+++ b/webAO/utils/filesExist.ts
@@ -0,0 +1,28 @@
+import fileExists from "./fileExists";
+
+/**
+ * This function takes a list of urls and returns the first one that exists.
+ * It checks all the URLs in parallel.
+ * @param urls the list of URLs to check
+ * @returns either the first URL that exists or null if none were found
+ */
+export default async function filesExist(urls: string[]): Promise<string | null> {
+    const promises = urls.map(async (url) => {
+        if (await fileExists(url)) {
+            return url;
+        }
+        return null;
+    });
+
+    // Run all in parallel
+    const results = await Promise.all(promises);
+
+    // Find the first URL that exists (not null) or return null if none exist
+    for (const result of results) {
+        if (result !== null) {
+            return result;
+        }
+    }
+
+    return null; // None of the URLs exist
+}