check timeout when doing a query to /keys to add an exchange

packages/taler-wallet-webextension/src/utils/index.ts

@@ -43,14 +43,37 @@ export async function queryToSlashConfig<T>(
     .then(getJsonIfOk);
 }
 
+function timeout<T>(ms: number, promise: Promise<T>): Promise<T> {
+  return new Promise((resolve, reject) => {
+    const timer = setTimeout(() => {
+      reject(new Error(`Timeout: the query took longer than ${Math.floor(ms / 1000)} secs`))
+    }, ms)
+
+    promise
+      .then(value => {
+        clearTimeout(timer)
+        resolve(value)
+      })
+      .catch(reason => {
+        clearTimeout(timer)
+        reject(reason)
+      })
+  })
+}
+
 export async function queryToSlashKeys<T>(
   url: string,
 ): Promise<T> {
-  return fetch(new URL("keys", url).href)
+  const endpoint = new URL("keys", url)
+  endpoint.searchParams.set("cacheBreaker", new Date().getTime() + "");
+
+  const query = fetch(endpoint.href)
     .catch(() => {
       throw new Error(`Network error`);
     })
     .then(getJsonIfOk);
+
+  return timeout(3000, query)
 }
 
 export function buildTermsOfServiceState(tos: GetExchangeTosResult): TermsState {

packages/taler-wallet-webextension/src/wallet/ExchangeAddPage.tsx

@@ -47,8 +47,15 @@ export function ExchangeAddPage({ onBack }: Props): VNode {
     return (
       <ExchangeSetUrlPage
         onCancel={onBack}
-        knownExchanges={knownExchanges}
-        onVerify={(url) => queryToSlashKeys(url)}
+        onVerify={async (url) => {
+          const found =
+            knownExchanges.findIndex((e) => e.exchangeBaseUrl === url) !== -1;
+
+          if (found) {
+            throw Error("This exchange is already known");
+          }
+          return queryToSlashKeys(url);
+        }}
         onConfirm={(url) =>
           queryToSlashKeys<TalerConfigResponse>(url)
             .then((config) => {

packages/taler-wallet-webextension/src/wallet/ExchangeAddSetUrl.stories.tsx

@@ -36,22 +36,18 @@ export default {
 export const ExpectedUSD = createExample(TestedComponent, {
   expectedCurrency: "USD",
   onVerify: queryToSlashKeys,
-  knownExchanges: [],
 });
 
 export const ExpectedKUDOS = createExample(TestedComponent, {
   expectedCurrency: "KUDOS",
   onVerify: queryToSlashKeys,
-  knownExchanges: [],
 });
 
 export const InitialState = createExample(TestedComponent, {
   onVerify: queryToSlashKeys,
-  knownExchanges: [],
 });
 
-export const WithDemoAsKnownExchange = createExample(TestedComponent, {
-  knownExchanges: [
+const knownExchanges = [
   {
     currency: "TESTKUDOS",
     exchangeBaseUrl: "https://exchange.demo.taler.net/",
@@ -63,6 +59,16 @@ export const WithDemoAsKnownExchange = createExample(TestedComponent, {
     },
     paytoUris: [],
   },
-  ],
-  onVerify: queryToSlashKeys,
+];
+
+export const WithDemoAsKnownExchange = createExample(TestedComponent, {
+  onVerify: async (url) => {
+    const found =
+      knownExchanges.findIndex((e) => e.exchangeBaseUrl === url) !== -1;
+
+    if (found) {
+      throw Error("This exchange is already known");
+    }
+    return queryToSlashKeys(url);
+  },
 });

packages/taler-wallet-webextension/src/wallet/ExchangeSetUrl.tsx

@@ -17,52 +17,75 @@ import {
 export interface Props {
   initialValue?: string;
   expectedCurrency?: string;
-  knownExchanges: ExchangeListItem[];
   onCancel: () => void;
   onVerify: (s: string) => Promise<TalerConfigResponse | undefined>;
   onConfirm: (url: string) => Promise<string | undefined>;
   withError?: string;
 }
 
+function useEndpointStatus<T>(
+  endpoint: string,
+  onVerify: (e: string) => Promise<T>,
+): {
+  loading: boolean;
+  error?: string;
+  endpoint: string;
+  result: T | undefined;
+  updateEndpoint: (s: string) => void;
+} {
+  const [value, setValue] = useState<string>(endpoint);
+  const [dirty, setDirty] = useState(false);
+  const [loading, setLoading] = useState(false);
+  const [result, setResult] = useState<T | undefined>(undefined);
+  const [error, setError] = useState<string | undefined>(undefined);
+
+  const [handler, setHandler] = useState<number | undefined>(undefined);
+
+  useEffect(() => {
+    if (!value) return;
+    window.clearTimeout(handler);
+    const h = window.setTimeout(async () => {
+      setDirty(true);
+      setLoading(true);
+      try {
+        const url = canonicalizeBaseUrl(value);
+        const result = await onVerify(url);
+        setResult(result);
+        setError(undefined);
+        setLoading(false);
+      } catch (e) {
+        const errorMessage =
+          e instanceof Error ? e.message : `unknown error: ${e}`;
+        setError(errorMessage);
+        setLoading(false);
+        setResult(undefined);
+      }
+    }, 500);
+    setHandler(h);
+  }, [value]);
+
+  return {
+    error: dirty ? error : undefined,
+    loading: loading,
+    result: result,
+    endpoint: value,
+    updateEndpoint: setValue,
+  };
+}
+
 export function ExchangeSetUrlPage({
   initialValue,
-  knownExchanges,
   expectedCurrency,
   onCancel,
   onVerify,
   onConfirm,
-  withError,
 }: Props) {
-  const [value, setValue] = useState<string>(initialValue || "");
-  const [dirty, setDirty] = useState(false);
-  const [result, setResult] = useState<TalerConfigResponse | undefined>(
-    undefined,
-  );
-  const [error, setError] = useState<string | undefined>(withError);
+  const { loading, result, endpoint, updateEndpoint, error } =
+    useEndpointStatus(initialValue ?? "", onVerify);
 
-  useEffect(() => {
-    try {
-      const url = canonicalizeBaseUrl(value);
-
-      const found =
-        knownExchanges.findIndex((e) => e.exchangeBaseUrl === url) !== -1;
-
-      if (found) {
-        setError("This exchange is already known");
-        return;
-      }
-      onVerify(url)
-        .then((r) => {
-          setResult(r);
-        })
-        .catch(() => {
-          setResult(undefined);
-        });
-      setDirty(true);
-    } catch {
-      setResult(undefined);
-    }
-  }, [value]);
+  const [confirmationError, setConfirmationError] = useState<
+    string | undefined
+  >(undefined);
 
   return (
     <Fragment>
@@ -72,21 +95,32 @@ export function ExchangeSetUrlPage({
         ) : (
           <h2>Add exchange for {expectedCurrency}</h2>
         )}
+        {result && expectedCurrency && expectedCurrency !== result.currency && (
+          <WarningBox>
+            This exchange doesn't match the expected currency{" "}
+            <b>{expectedCurrency}</b>
+          </WarningBox>
+        )}
         <ErrorMessage
           title={error && "Unable to add this exchange"}
           description={error}
         />
+        <ErrorMessage
+          title={confirmationError && "Unable to add this exchange"}
+          description={confirmationError}
+        />
         <p>
-          <Input invalid={dirty && !!error}>
+          <Input invalid={!!error}>
             <label>URL</label>
             <input
               type="text"
               placeholder="https://"
-              value={value}
-              onInput={(e) => setValue(e.currentTarget.value)}
+              value={endpoint}
+              onInput={(e) => updateEndpoint(e.currentTarget.value)}
             />
           </Input>
-          {result && (
+          {loading && <div>loading... </div>}
+          {result && !loading && (
             <Fragment>
               <Input>
                 <label>Version</label>
@@ -100,12 +134,6 @@ export function ExchangeSetUrlPage({
           )}
         </p>
       </section>
-      {result && expectedCurrency && expectedCurrency !== result.currency && (
-        <WarningBox>
-          This exchange doesn't match the expected currency{" "}
-          <b>{expectedCurrency}</b>
-        </WarningBox>
-      )}
       <footer>
         <Button onClick={onCancel}>
           <i18n.Translate>Cancel</i18n.Translate>
@@ -118,8 +146,10 @@ export function ExchangeSetUrlPage({
               expectedCurrency !== result.currency)
           }
           onClick={() => {
-            const url = canonicalizeBaseUrl(value);
-            return onConfirm(url).then((r) => (r ? setError(r) : undefined));
+            const url = canonicalizeBaseUrl(endpoint);
+            return onConfirm(url).then((r) =>
+              r ? setConfirmationError(r) : undefined,
+            );
           }}
         >
           <i18n.Translate>Next</i18n.Translate>