make static

src/configFetch.ts

@@ -0,0 +1,66 @@
+import { loadConfig } from "./configLoader";
+import type { ConfigResult } from "./types";
+
+/**
+ * Fetch and validate config.json at runtime. The URL is resolved against the
+ * app's configured base (import.meta.env.BASE_URL), so it works whether the app
+ * is served from a domain root or a subpath.
+ */
+export async function fetchConfig(): Promise<ConfigResult> {
+  const url = configUrl();
+
+  let response: Response;
+  try {
+    response = await fetch(url.toString(), { cache: "no-cache" });
+  } catch (err) {
+    return {
+      ok: false,
+      errors: [`Could not fetch config.json (${describe(err)}).`],
+    };
+  }
+
+  if (!response.ok) {
+    return {
+      ok: false,
+      errors: [
+        `Could not load config.json (HTTP ${response.status} ${response.statusText}).`,
+      ],
+    };
+  }
+
+  let raw: unknown;
+  try {
+    raw = await response.json();
+  } catch {
+    return {
+      ok: false,
+      errors: ["config.json is not valid JSON."],
+    };
+  }
+
+  return loadConfig(raw);
+}
+
+/**
+ * Resolve the config.json URL for the deployed location. Uses Vite's configured
+ * base when it is an absolute path (e.g. "/meal-estimator/"); otherwise falls
+ * back to the directory of the current document so a relative "./" base works
+ * whether or not the URL has a trailing slash.
+ */
+function configUrl(): string {
+  const base = import.meta.env.BASE_URL;
+
+  if (base.startsWith("/")) {
+    // Absolute base path: config sits directly under it.
+    return new URL(`${base}config.json`, window.location.origin).toString();
+  }
+
+  // Relative base: resolve against the current document's directory.
+  const path = window.location.pathname;
+  const dir = path.endsWith("/") ? path : path.slice(0, path.lastIndexOf("/") + 1);
+  return new URL(`${dir}config.json`, window.location.origin).toString();
+}
+
+function describe(err: unknown): string {
+  return err instanceof Error ? err.message : "network error";
+}