Merge pull request #322 from mittwald/bugfix/fix-eventual-consistency…

…-again

Fix bugs introduced by eventual-consistency handling

src/lib/api_consistency.ts

@@ -5,9 +5,13 @@ const d = debug("mw:api-consistency");
 
 export function configureConsistencyHandling(axios: AxiosInstance) {
   let lastEventId: string | undefined = undefined;
+  let mutatedPaths: string[] | undefined = undefined;
 
   axios.interceptors.request.use((config) => {
-    if (lastEventId !== undefined) {
+    if (
+      lastEventId !== undefined &&
+      mutatedPaths?.some((path) => config.url?.startsWith(path))
+    ) {
       d("setting if-event-reached to %o", lastEventId);
       config.headers["if-event-reached"] = lastEventId;
     }
@@ -22,11 +26,18 @@ export function configureConsistencyHandling(axios: AxiosInstance) {
     const headers = response.headers as AxiosHeaders;
 
     if (headers.has("etag") && isMutatingRequest) {
+      lastEventId = headers.get("etag") as string;
+
+      const mutatedPath = response.config?.url;
+      if (mutatedPath !== undefined) {
+        mutatedPaths = [mutatedPath];
+      }
+
       d(
-        "setting last event id to %o after mutating request",
-        headers.get("etag"),
+        "setting last event id to %o after mutating request for path %o",
+        headers["etag"],
+        mutatedPath,
       );
-      lastEventId = headers.get("etag") as string;
     }
     return response;
   });

src/lib/api_retry.ts

@@ -24,7 +24,10 @@ export function configureAxiosRetry(axios: AxiosInstance) {
   axiosRetry(axios, {
     retries: 10,
     retryDelay: axiosRetry.exponentialDelay,
-    onRetry(count, error) {
+    onRetry(count, error, config) {
+      if (error.response?.status === 412 && config.headers !== undefined) {
+        delete config.headers["if-event-reached"];
+      }
       d("retrying request after %d attempts; error: %o", count, error.message);
     },
     retryCondition(error) {
@@ -37,8 +40,13 @@ export function configureAxiosRetry(axios: AxiosInstance) {
       }
 
       const isSafeRequest = error.config?.method?.toLowerCase() === "get";
+      const isPreconditionFailed = error.response?.status === 412;
       const isAccessDenied = error.response?.status === 403;
 
+      if (isPreconditionFailed) {
+        return true;
+      }
+
       return isSafeRequest && isAccessDenied && shouldRetryAccessDenied;
     },
   });