Add error type wrapper and missing error cause

src/lib/components/app/HealthLink.svelte

@@ -26,6 +26,7 @@
   import { goto } from '$app/navigation';
   import type { Writable } from 'svelte/store';
   import type { SHLAdminParams, SHLClient } from '$lib/utils/managementClient';
+  import { ensureError } from '$lib/utils/util';
 
   export let shl: SHLAdminParams;
   let shlControlled: SHLAdminParams;
@@ -63,7 +64,7 @@
     try {
       linkIsActive = await shlClient.isActive(shl.id);
     } catch (e) {
-      console.error(e);
+      console.error(ensureError(e).message);
       linkNotFound = true;
     }
   });
@@ -75,7 +76,7 @@
     const qrCode = await new Promise((resolve, reject) => {
         const img = new Image();
         img.onload = () => resolve(img);
-        img.onerror = (err) => reject(new Error('Failed to load image from data URI.'));
+        img.onerror = (err) => reject(new Error('Failed to load image from data URI.', { cause: err }));
         img.src = qrCodeURI;
       }) as HTMLImageElement;
     // get the header and footer images

src/lib/utils/util.ts

@@ -6,6 +6,17 @@ import type { Bundle, BundleEntry, Resource } from 'fhir/r4';
 
 export const base64url = jose.base64url;
 
+export function ensureError(value: unknown): Error {
+  if (value instanceof Error) return value;
+  let stringifiedValue = "[Unable to stringify the thrown value]";
+  try {
+    stringifiedValue = JSON.stringify(value);
+  } catch (e) {}
+
+  const error = new Error(`This value was thrown, but it was not an Error object: ${stringifiedValue}`);
+  return error
+}
+
 export function randomStringWithEntropy(entropy = 32): string {
   const b = new Uint8Array(entropy);
   crypto.getRandomValues(b);