fix(agent/agentcontainers): broadcast devcontainer dirty status over websocket

mafredri · mafredri · commit 9a7d18a16b48 · 2025-12-04T12:59:33.000Z
Previously, when a devcontainer config file was modified, the dirty
status was updated internally but not broadcast to websocket listeners.
This meant the UI would not show the dirty indicator until some other
event triggered a broadcast (e.g., container restart or updater loop).

Add broadcastUpdatesLocked() call in markDevcontainerDirty to notify
websocket listeners immediately when a config file changes.
diff --git a/agent/agentcontainers/api.go b/agent/agentcontainers/api.go
@@ -1457,6 +1457,8 @@ func (api *API) markDevcontainerDirty(configPath string, modifiedAt time.Time) {
 
 		api.knownDevcontainers[dc.WorkspaceFolder] = dc
 	}
+
+	api.broadcastUpdatesLocked()
 }
 
 // cleanupSubAgents removes subagents that are no longer managed by
diff --git a/agent/agentcontainers/api_test.go b/agent/agentcontainers/api_test.go
@@ -1641,6 +1641,77 @@ func TestAPI(t *testing.T) {
 		require.NotNil(t, response.Devcontainers[0].Container, "container should not be nil")
 	})
 
+	// Verify that modifying a config file broadcasts the dirty status
+	// over websocket immediately.
+	t.Run("FileWatcherDirtyBroadcast", func(t *testing.T) {
+		t.Parallel()
+
+		ctx := testutil.Context(t, testutil.WaitShort)
+		configPath := "/workspace/project/.devcontainer/devcontainer.json"
+		fWatcher := newFakeWatcher(t)
+		fLister := &fakeContainerCLI{
+			containers: codersdk.WorkspaceAgentListContainersResponse{
+				Containers: []codersdk.WorkspaceAgentContainer{
+					{
+						ID:           "container-id",
+						FriendlyName: "container-name",
+						Running:      true,
+						Labels: map[string]string{
+							agentcontainers.DevcontainerLocalFolderLabel: "/workspace/project",
+							agentcontainers.DevcontainerConfigFileLabel:  configPath,
+						},
+					},
+				},
+			},
+		}
+
+		mClock := quartz.NewMock(t)
+		tickerTrap := mClock.Trap().TickerFunc("updaterLoop")
+
+		api := agentcontainers.NewAPI(
+			slogtest.Make(t, nil).Leveled(slog.LevelDebug),
+			agentcontainers.WithContainerCLI(fLister),
+			agentcontainers.WithWatcher(fWatcher),
+			agentcontainers.WithClock(mClock),
+		)
+		api.Start()
+		defer api.Close()
+
+		srv := httptest.NewServer(api.Routes())
+		defer srv.Close()
+
+		tickerTrap.MustWait(ctx).MustRelease(ctx)
+		tickerTrap.Close()
+
+		wsConn, resp, err := websocket.Dial(ctx, "ws"+strings.TrimPrefix(srv.URL, "http")+"/watch", nil)
+		require.NoError(t, err)
+		if resp != nil && resp.Body != nil {
+			defer resp.Body.Close()
+		}
+		defer wsConn.Close(websocket.StatusNormalClosure, "")
+
+		// Read and discard initial state.
+		_, _, err = wsConn.Read(ctx)
+		require.NoError(t, err)
+
+		fWatcher.waitNext(ctx)
+		fWatcher.sendEventWaitNextCalled(ctx, fsnotify.Event{
+			Name: configPath,
+			Op:   fsnotify.Write,
+		})
+
+		// Verify dirty status is broadcast without advancing the clock.
+		_, msg, err := wsConn.Read(ctx)
+		require.NoError(t, err)
+
+		var response codersdk.WorkspaceAgentListContainersResponse
+		err = json.Unmarshal(msg, &response)
+		require.NoError(t, err)
+		require.Len(t, response.Devcontainers, 1)
+		assert.True(t, response.Devcontainers[0].Dirty,
+			"devcontainer should be marked as dirty after config file modification")
+	})
+
 	t.Run("SubAgentLifecycle", func(t *testing.T) {
 		t.Parallel()
 

Original file line number	Diff line number	Diff line change
`@@ -1457,6 +1457,8 @@ func (api *API) markDevcontainerDirty(configPath string, modifiedAt time.Time) {`
`1457`	`1457`
`1458`	`1458`	`api.knownDevcontainers[dc.WorkspaceFolder] = dc`
`1459`	`1459`	`}`
	`1460`	`+`
	`1461`	`+ api.broadcastUpdatesLocked()`
`1460`	`1462`	`}`
`1461`	`1463`
`1462`	`1464`	`// cleanupSubAgents removes subagents that are no longer managed by`