show reducer network errors

packages/anastasis-webui/src/hooks/use-anastasis-reducer.ts

@@ -1,3 +1,4 @@
+import { TalerErrorCode } from "@gnu-taler/taler-util";
 import { useState } from "preact/hooks";
 
 export type ReducerState =
@@ -138,13 +139,44 @@ export enum RecoveryStates {
 const reducerBaseUrl = "http://localhost:5000/";
 
 async function getBackupStartState(): Promise<ReducerState> {
-  const resp = await fetch(new URL("start-backup", reducerBaseUrl).href);
+  let resp: Response;
+
+  try {
+    resp = await fetch(new URL("start-backup", reducerBaseUrl).href);
+  } catch (e) {
+    return {
+      code: TalerErrorCode.ANASTASIS_REDUCER_NETWORK_FAILED,
+      message: `Network request to remote reducer ${reducerBaseUrl} failed`,
+    } as any;
+  }
+  try {
     return await resp.json();
+  } catch (e) {
+    return {
+      code: TalerErrorCode.ANASTASIS_REDUCER_NETWORK_FAILED,
+      message: `Could not parse response from reducer`,
+    } as any;
+  }
 }
 
 async function getRecoveryStartState(): Promise<ReducerState> {
-  const resp = await fetch(new URL("start-recovery", reducerBaseUrl).href);
+  let resp: Response;
+  try {
+    resp = await fetch(new URL("start-recovery", reducerBaseUrl).href);
+  } catch (e) {
+    return {
+      code: TalerErrorCode.ANASTASIS_REDUCER_NETWORK_FAILED,
+      message: `Network request to remote reducer ${reducerBaseUrl} failed`,
+    } as any;
+  }
+  try {
     return await resp.json();
+  } catch (e) {
+    return {
+      code: TalerErrorCode.ANASTASIS_REDUCER_NETWORK_FAILED,
+      message: `Could not parse response from reducer`,
+    } as any;
+  }
 }
 
 async function reduceState(
@@ -152,7 +184,9 @@ async function reduceState(
   action: string,
   args: any,
 ): Promise<ReducerState> {
-  const resp = await fetch(new URL("action", reducerBaseUrl).href, {
+  let resp: Response;
+  try {
+    resp = await fetch(new URL("action", reducerBaseUrl).href, {
       method: "POST",
       headers: {
         Accept: "application/json",
@@ -164,7 +198,20 @@ async function reduceState(
         arguments: args,
       }),
     });
-  return resp.json();
+  } catch (e) {
+    return {
+      code: TalerErrorCode.ANASTASIS_REDUCER_NETWORK_FAILED,
+      message: `Network request to remote reducer ${reducerBaseUrl} failed`,
+    } as any;
+  }
+  try {
+    return await resp.json();
+  } catch (e) {
+    return {
+      code: TalerErrorCode.ANASTASIS_REDUCER_NETWORK_FAILED,
+      message: `Could not parse response from reducer`,
+    } as any;
+  }
 }
 
 export interface ReducerTransactionHandle {
@@ -244,19 +291,33 @@ export function useAnastasisReducer(): AnastasisReducerApi {
     currentError: anastasisState.currentError,
     async startBackup() {
       const s = await getBackupStartState();
+      if (s.code !== undefined) {
+        setAnastasisState({
+          ...anastasisState,
+          currentError: s,
+        });
+      } else {
         setAnastasisState({
           ...anastasisState,
           currentError: undefined,
           reducerState: s,
         });
+      }
     },
     async startRecover() {
       const s = await getRecoveryStartState();
+      if (s.code !== undefined) {
+        setAnastasisState({
+          ...anastasisState,
+          currentError: s,
+        });
+      } else {
         setAnastasisState({
           ...anastasisState,
           currentError: undefined,
           reducerState: s,
         });
+      }
     },
     transition(action: string, args: any) {
       doTransition(action, args);