Webview: improve error debug abilities

pkgs/webview-ui/app/src/api.ts

@@ -94,12 +94,30 @@ type PyApi = {
   };
 };
 
+function download(filename: string, text: string) {
+  const element = document.createElement("a");
+  element.setAttribute(
+    "href",
+    "data:text/plain;charset=utf-8," + encodeURIComponent(text)
+  );
+  element.setAttribute("download", filename);
+
+  element.style.display = "none";
+  document.body.appendChild(element);
+
+  element.click();
+
+  document.body.removeChild(element);
+}
+
 const deserialize =
   <T>(fn: (response: T) => void) =>
   (str: string) => {
     try {
       fn(JSON.parse(str) as T);
     } catch (e) {
+      console.log("Error parsing JSON: ", e);
+      console.log({ download: () => download("error.json", str) });
       console.error(str);
       alert(`Error parsing JSON: ${e}`);
     }

pkgs/webview-ui/app/util.ts

@@ -0,0 +1,33 @@
+export function isValidHostname(value: string | null | undefined) {
+  if (typeof value !== "string") return false;
+
+  const validHostnameChars = /^[a-zA-Z0-9-.]{1,253}\.?$/g;
+
+  if (!validHostnameChars.test(value)) {
+    return false;
+  }
+
+  if (value.endsWith(".")) {
+    value = value.slice(0, value.length - 1);
+  }
+
+  if (value.length > 253) {
+    return false;
+  }
+
+  const labels = value.split(".");
+
+  const isValid = labels.every(function (label) {
+    const validLabelChars = /^([a-zA-Z0-9-]+)$/g;
+
+    const validLabel =
+      validLabelChars.test(label) &&
+      label.length < 64 &&
+      !label.startsWith("-") &&
+      !label.endsWith("-");
+
+    return validLabel;
+  });
+
+  return isValid;
+}