🔧 fix: Improve Endpoint Handling and Address Edge Cases (#1486)

* fix(TEndpointsConfig): resolve property access issues with typesafe helper function

* fix: undefined or null endpoint edge case

* refactor(mapEndpoints -> endpoints): renamed module to be more general for endpoint handling, wrote unit tests, export all helpers

client/src/utils/endpoints.ts

@@ -0,0 +1,58 @@
+import { defaultEndpoints } from 'librechat-data-provider';
+import type { EModelEndpoint, TEndpointsConfig, TConfig } from 'librechat-data-provider';
+
+export const getEndpointsFilter = (endpointsConfig: TEndpointsConfig) => {
+  const filter: Record<string, boolean> = {};
+  if (!endpointsConfig) {
+    return filter;
+  }
+  for (const key of Object.keys(endpointsConfig)) {
+    filter[key] = !!endpointsConfig[key];
+  }
+  return filter;
+};
+
+export const getAvailableEndpoints = (
+  filter: Record<string, boolean>,
+  endpointsConfig: TEndpointsConfig,
+) => {
+  const defaultSet = new Set(defaultEndpoints);
+  const availableEndpoints: EModelEndpoint[] = [];
+
+  for (const endpoint in endpointsConfig) {
+    // Check if endpoint is in the filter or its type is in defaultEndpoints
+    if (
+      filter[endpoint] ||
+      (endpointsConfig[endpoint]?.type &&
+        defaultSet.has(endpointsConfig[endpoint]?.type as EModelEndpoint))
+    ) {
+      availableEndpoints.push(endpoint as EModelEndpoint);
+    }
+  }
+
+  return availableEndpoints;
+};
+
+export function getEndpointField<K extends keyof TConfig>(
+  endpointsConfig: TEndpointsConfig | undefined,
+  endpoint: EModelEndpoint | string | null | undefined,
+  property: K,
+): TConfig[K] | undefined {
+  if (!endpointsConfig || endpoint === null || endpoint === undefined) {
+    return undefined;
+  }
+
+  const config = endpointsConfig[endpoint];
+  if (!config) {
+    return undefined;
+  }
+
+  return config[property];
+}
+
+export function mapEndpoints(endpointsConfig: TEndpointsConfig) {
+  const filter = getEndpointsFilter(endpointsConfig);
+  return getAvailableEndpoints(filter, endpointsConfig).sort(
+    (a, b) => (endpointsConfig?.[a]?.order ?? 0) - (endpointsConfig?.[b]?.order ?? 0),
+  );
+}