Add View Servers in Room to Devtools

res/css/views/dialogs/_DevtoolsDialog.scss

@@ -18,7 +18,12 @@ limitations under the License.
     margin: 10px 0;
 }
 
-.mx_DevTools_RoomStateExplorer_button, .mx_DevTools_RoomStateExplorer_query {
+.mx_DevTools_ServersInRoomList_button {
+    /* Set the cursor back to default as `.mx_Dialog button` sets it to pointer */
+    cursor: default !important;
+}
+
+.mx_DevTools_RoomStateExplorer_button, .mx_DevTools_ServersInRoomList_button, .mx_DevTools_RoomStateExplorer_query {
     margin-bottom: 10px;
     width: 100%;
 }

src/components/views/dialogs/DevtoolsDialog.js

@@ -551,11 +551,53 @@ class AccountDataExplorer extends DevtoolsComponent {
     }
 }
 
+class ServersInRoomList extends DevtoolsComponent {
+    static getLabel() { return _t('View Servers in Room'); }
+
+    static propTypes = {
+        onBack: PropTypes.func.isRequired,
+    };
+
+    constructor(props, context) {
+        super(props, context);
+
+        const room = MatrixClientPeg.get().getRoom(this.context.roomId);
+        const servers = new Set();
+        room.currentState.getStateEvents("m.room.member").forEach(ev => servers.add(ev.getSender().split(":")[1]));
+        this.servers = Array.from(servers).map(s =>
+            <button key={s} className="mx_DevTools_ServersInRoomList_button">
+                { s }
+            </button>);
+
+        this.state = {
+            query: '',
+        };
+    }
+
+    onQuery = (query) => {
+        this.setState({ query });
+    }
+
+    render() {
+        return <div>
+            <div className="mx_Dialog_content">
+                <FilteredList query={this.state.query} onChange={this.onQuery}>
+                    { this.servers }
+                </FilteredList>
+            </div>
+            <div className="mx_Dialog_buttons">
+                <button onClick={this.props.onBack}>{ _t('Back') }</button>
+            </div>
+        </div>;
+    }
+}
+
 const Entries = [
     SendCustomEvent,
     RoomStateExplorer,
     SendAccountData,
     AccountDataExplorer,
+    ServersInRoomList,
 ];
 
 export default class DevtoolsDialog extends React.Component {

src/i18n/strings/en_EN.json

@@ -1133,6 +1133,7 @@
     "Filter results": "Filter results",
     "Explore Room State": "Explore Room State",
     "Explore Account Data": "Explore Account Data",
+    "View Servers in Room": "View Servers in Room",
     "Toolbox": "Toolbox",
     "Developer Tools": "Developer Tools",
     "An error has occurred.": "An error has occurred.",