From 6bf69eb1435f495dad7625ae1db79b06c0bea4d5 Mon Sep 17 00:00:00 2001
From: Germain <germain@souquet.com>
Date: Mon, 31 Oct 2022 16:56:14 +0000
Subject: [PATCH 1/6] Catch server versions API call exception when starting
 the client

---
 src/client.ts | 40 +++++++++++++++++++++++++---------------
 1 file changed, 25 insertions(+), 15 deletions(-)

diff --git a/src/client.ts b/src/client.ts
index 67d56f7b942..d0ca25141e2 100644
--- a/src/client.ts
+++ b/src/client.ts
@@ -1193,11 +1193,11 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
             this.syncApi.stop();
         }
 
-        const serverVersions = await this.getVersions();
-        this.canSupport = await buildFeatureSupportMap(serverVersions);
-
-        const support = this.canSupport.get(Feature.ThreadUnreadNotifications);
-        UNREAD_THREAD_NOTIFICATIONS.setPreferUnstable(support === ServerSupport.Unstable);
+        try {
+            await this.getVersions();
+        } catch (e) {
+            logger.error("Can't fetch server versions, continuing to initialise sync, this will be retried later", e);
+        }
 
         const { threads, list, fwdPagination } = await this.doesServerSupportThread();
         Thread.setServerSideSupport(threads);
@@ -6712,24 +6712,34 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
      * unstable APIs it supports
      * @return {Promise<object>} The server /versions response
      */
-    public getVersions(): Promise<IServerVersions> {
+    public async getVersions(): Promise<IServerVersions> {
         if (this.serverVersionsPromise) {
             return this.serverVersionsPromise;
         }
 
-        this.serverVersionsPromise = this.http.request<IServerVersions>(
-            Method.Get, "/_matrix/client/versions",
-            undefined, // queryParams
-            undefined, // data
-            {
-                prefix: '',
-            },
-        ).catch((e: Error) => {
+        try {
+            this.serverVersionsPromise = this.http.request<IServerVersions>(
+                Method.Get, "/_matrix/client/versions",
+                undefined, // queryParams
+                undefined, // data
+                {
+                    prefix: '',
+                },
+            );
+            // throw "YOLO";
+        } catch (e) {
             // Need to unset this if it fails, otherwise we'll never retry
             this.serverVersionsPromise = undefined;
             // but rethrow the exception to anything that was waiting
             throw e;
-        });
+        }
+
+        const serverVersions = await this.serverVersionsPromise;
+        this.canSupport = await buildFeatureSupportMap(serverVersions);
+
+        // We can set flag values to use their stable or unstable version
+        const support = this.canSupport.get(Feature.ThreadUnreadNotifications);
+        UNREAD_THREAD_NOTIFICATIONS.setPreferUnstable(support === ServerSupport.Unstable);
 
         return this.serverVersionsPromise;
     }

From c839779f78adcadfd984cb26854924b4bcaee0a2 Mon Sep 17 00:00:00 2001
From: Germain <germain@souquet.com>
Date: Mon, 31 Oct 2022 17:03:17 +0000
Subject: [PATCH 2/6] Remove log line

---
 src/client.ts | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/client.ts b/src/client.ts
index d0ca25141e2..7ff2fe17cc4 100644
--- a/src/client.ts
+++ b/src/client.ts
@@ -6726,7 +6726,6 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
                     prefix: '',
                 },
             );
-            // throw "YOLO";
         } catch (e) {
             // Need to unset this if it fails, otherwise we'll never retry
             this.serverVersionsPromise = undefined;

From 88ae78f6ea60abeaf24383c2345154a523b65def Mon Sep 17 00:00:00 2001
From: Germain <germain@souquet.com>
Date: Mon, 31 Oct 2022 17:07:02 +0000
Subject: [PATCH 3/6] Add test when all API call fail in startClient

---
 spec/integ/matrix-client-syncing.spec.ts | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/spec/integ/matrix-client-syncing.spec.ts b/spec/integ/matrix-client-syncing.spec.ts
index 3609e8a0f3d..d9099444273 100644
--- a/spec/integ/matrix-client-syncing.spec.ts
+++ b/spec/integ/matrix-client-syncing.spec.ts
@@ -274,6 +274,15 @@ describe("MatrixClient syncing", () => {
 
             expect(fires).toBe(1);
         });
+
+        it("should work when all network calls fail", async () => {
+            httpBackend!.when("GET", "").fail(0, new Error("CORS or something"));
+            const prom = client!.startClient();
+            await Promise.all([
+                expect(prom).resolves.toBeUndefined(),
+            httpBackend!.flushAllExpected(),
+            ]);
+        });
     });
 
     describe("initial sync", () => {

From 44e8fbcb12fdac5d7e2dd1674e061bd4999e867c Mon Sep 17 00:00:00 2001
From: Germain <germain@souquet.com>
Date: Mon, 31 Oct 2022 17:18:36 +0000
Subject: [PATCH 4/6] Fix try/catch in getVersions

---
 src/client.ts | 20 +++++++++-----------
 1 file changed, 9 insertions(+), 11 deletions(-)

diff --git a/src/client.ts b/src/client.ts
index 7ff2fe17cc4..3b752e77ab6 100644
--- a/src/client.ts
+++ b/src/client.ts
@@ -6717,21 +6717,19 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
             return this.serverVersionsPromise;
         }
 
-        try {
-            this.serverVersionsPromise = this.http.request<IServerVersions>(
-                Method.Get, "/_matrix/client/versions",
-                undefined, // queryParams
-                undefined, // data
-                {
-                    prefix: '',
-                },
-            );
-        } catch (e) {
+        this.serverVersionsPromise = this.http.request<IServerVersions>(
+            Method.Get, "/_matrix/client/versions",
+            undefined, // queryParams
+            undefined, // data
+            {
+                prefix: '',
+            },
+        ).catch(e => {
             // Need to unset this if it fails, otherwise we'll never retry
             this.serverVersionsPromise = undefined;
             // but rethrow the exception to anything that was waiting
             throw e;
-        }
+        });
 
         const serverVersions = await this.serverVersionsPromise;
         this.canSupport = await buildFeatureSupportMap(serverVersions);

From c273b9813dd2f6c5174245f3f31d6c97d8c85eb6 Mon Sep 17 00:00:00 2001
From: Germain <germain@souquet.com>
Date: Mon, 31 Oct 2022 17:29:39 +0000
Subject: [PATCH 5/6] Move threads feature detection in try/catch

---
 src/client.ts | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/src/client.ts b/src/client.ts
index 3b752e77ab6..4c380ec4138 100644
--- a/src/client.ts
+++ b/src/client.ts
@@ -1195,15 +1195,17 @@ export class MatrixClient extends TypedEventEmitter<EmittedEvents, ClientEventHa
 
         try {
             await this.getVersions();
+
+            // This should be done with `canSupport`
+            // TODO: https://github.com/vector-im/element-web/issues/23643
+            const { threads, list, fwdPagination } = await this.doesServerSupportThread();
+            Thread.setServerSideSupport(threads);
+            Thread.setServerSideListSupport(list);
+            Thread.setServerSideFwdPaginationSupport(fwdPagination);
         } catch (e) {
             logger.error("Can't fetch server versions, continuing to initialise sync, this will be retried later", e);
         }
 
-        const { threads, list, fwdPagination } = await this.doesServerSupportThread();
-        Thread.setServerSideSupport(threads);
-        Thread.setServerSideListSupport(list);
-        Thread.setServerSideFwdPaginationSupport(fwdPagination);
-
         // shallow-copy the opts dict before modifying and storing it
         this.clientOpts = Object.assign({}, opts) as IStoredClientOpts;
         this.clientOpts.crypto = this.crypto;

From f0b5779084ae04b991948bafe910dcba1ef66196 Mon Sep 17 00:00:00 2001
From: Germain <germain@souquet.com>
Date: Mon, 31 Oct 2022 17:34:41 +0000
Subject: [PATCH 6/6] reset expected requests to sure /versions fails

---
 spec/integ/matrix-client-syncing.spec.ts | 1 +
 1 file changed, 1 insertion(+)

diff --git a/spec/integ/matrix-client-syncing.spec.ts b/spec/integ/matrix-client-syncing.spec.ts
index d9099444273..418e2d16add 100644
--- a/spec/integ/matrix-client-syncing.spec.ts
+++ b/spec/integ/matrix-client-syncing.spec.ts
@@ -276,6 +276,7 @@ describe("MatrixClient syncing", () => {
         });
 
         it("should work when all network calls fail", async () => {
+            httpBackend!.expectedRequests = [];
             httpBackend!.when("GET", "").fail(0, new Error("CORS or something"));
             const prom = client!.startClient();
             await Promise.all([