1 files changed, 58 insertions, 31 deletions

diff --git a/packages/anastasis-webui/src/pages/home/AddingProviderScreen/index.ts b/packages/anastasis-webui/src/pages/home/AddingProviderScreen/index.ts
index 0ab275f54..ed8301d65 100644
--- a/packages/anastasis-webui/src/pages/home/AddingProviderScreen/index.ts
+++ b/packages/anastasis-webui/src/pages/home/AddingProviderScreen/index.ts
@@ -24,7 +24,7 @@ import { WithoutProviderType, WithProviderType } from "./views.js";
 export type AuthProvByStatusMap = Record<
   AuthenticationProviderStatus["status"],
   (AuthenticationProviderStatus & { url: string })[]
->
+>;
 
 export type State = NoReducer | InvalidState | WithType | WithoutType;
 
@@ -63,42 +63,69 @@ const map: StateViewMap<State> = {
   "without-type": WithoutProviderType,
 };
 
-export default compose("AddingProviderScreen", useComponentState, map)
-
+export default compose("AddingProviderScreen", useComponentState, map);
 
+const providerResponseCache = new Map<string, any>(); // `any` is the return type of res.json()
 export async function testProvider(
   url: string,
   expectedMethodType?: string,
 ): Promise<void> {
+  const testFatalPrefix = `Encountered a fatal error whilst testing the provider ${url}`;
+  let configUrl = "";
   try {
-    const response = await fetch(new URL("config", url).href);
-    const json = await response.json().catch((d) => ({}));
-    if (!("methods" in json) || !Array.isArray(json.methods)) {
-      throw Error(
-        "This provider doesn't have authentication method. Check the provider URL",
-      );
-    }
-    if (!expectedMethodType) {
-      return;
-    }
-    let found = false;
-    for (let i = 0; i < json.methods.length && !found; i++) {
-      found = json.methods[i].type === expectedMethodType;
-    }
-    if (!found) {
-      throw Error(
-        `This provider does not support authentication method ${expectedMethodType}`,
-      );
-    }
+    configUrl = new URL("config", url).href;
+  } catch (error) {
+    throw new Error(`${testFatalPrefix}: Invalid Provider URL: ${url}
+Error: ${error}`);
+  }
+  // TODO: look into using core.getProviderInfo :)
+  const providerHasUrl = providerResponseCache.has(url);
+  const json = providerHasUrl
+    ? providerResponseCache.get(url)
+    : await fetch(configUrl)
+        .catch((error) => {
+          throw new Error(`${testFatalPrefix}: Could not connect: ${error}
+Please check the URL.`);
+        })
+        .then(async (response) => {
+          if (!response.ok)
+            throw new Error(
+              `${testFatalPrefix}: The server ${response.url} responded with a non-2xx response.`,
+            );
+          try {
+            return await response.json();
+          } catch (error) {
+            throw new Error(
+              `${testFatalPrefix}: The server responded with malformed JSON.\nError: ${error}`,
+            );
+          }
+        });
+  if (typeof json !== "object")
+    throw new Error(
+      `${testFatalPrefix}: Did not get an object after decoding.`,
+    );
+  if (!("name" in json) || json.name !== "anastasis") {
+    throw new Error(
+      `${testFatalPrefix}: The provider does not appear to be an Anastasis provider. Please check the provider's URL.`,
+    );
+  }
+  if (!("methods" in json) || !Array.isArray(json.methods)) {
+    throw new Error(
+      "This provider doesn't have authentication method. Please check the provider's URL and ensure it is properly configured.",
+    );
+  }
+  if (!providerHasUrl) providerResponseCache.set(url, json);
+  if (!expectedMethodType) {
     return;
-  } catch (e) {
-    console.log("ERROR testProvider", e);
-    const error =
-      e instanceof Error
-        ? Error(
-          `There was an error testing this provider, try another one. ${e.message}`,
-        )
-        : Error(`There was an error testing this provider, try another one.`);
-    throw error;
   }
+  let found = false;
+  for (let i = 0; i < json.methods.length && !found; i++) {
+    found = json.methods[i].type === expectedMethodType;
+  }
+  if (!found) {
+    throw new Error(
+      `${testFatalPrefix}: This provider does not support authentication method ${expectedMethodType}`,
+    );
+  }
+  return;
 }