Don't show the same user twice in Spotlight

cypress/integration/12-spotlight/spotlight.spec.ts

@@ -55,6 +55,7 @@ declare global {
             roomHeaderName(
                 options?: Partial<Loggable & Timeoutable & Withinable & Shadow>
             ): Chainable<JQuery<HTMLElement>>;
+            startDM(name: string): Chainable<void>;
         }
     }
 }
@@ -109,6 +110,16 @@ Cypress.Commands.add("roomHeaderName", (
     return cy.get(".mx_RoomHeader_nametext", options);
 });
 
+Cypress.Commands.add("startDM", (name: string) => {
+    cy.openSpotlightDialog().within(() => {
+        cy.spotlightFilter(Filter.People);
+        cy.spotlightSearch().clear().type(name);
+        cy.spotlightResults().eq(0).click();
+    });
+    // Opening a DM takes time...
+    cy.wait(3000);
+});
+
 describe("Spotlight", () => {
     let synapse: SynapseInstance;
 
@@ -319,6 +330,24 @@ describe("Spotlight", () => {
         });
     });
 
+    it("should close spotlight after starting a DM", () => {
+        cy.startDM(bot1Name);
+        cy.get(".mx_SpotlightDialog").should("have.length", 0);
+    });
+
+    it("should show the same user only once", () => {
+        cy.startDM(bot1Name);
+        cy.visit("/#/home");
+
+        cy.openSpotlightDialog().within(() => {
+            cy.spotlightFilter(Filter.People);
+            cy.spotlightSearch().clear().type(bot1Name);
+            // Sometimes it take a bit of time for all the results to show up
+            cy.wait(100);
+            cy.spotlightResults().should("have.length", 1);
+        });
+    });
+
     it("should be able to navigate results via keyboard", () => {
         cy.openSpotlightDialog().within(() => {
             cy.spotlightFilter(Filter.People);

src/components/views/dialogs/spotlight/SpotlightDialog.tsx

@@ -322,7 +322,7 @@ const SpotlightDialog: React.FC<IProps> = ({ initialText = "", initialFilter = n
         () => {
             const roomMembers = findVisibleRoomMembers(cli);
             const roomMemberIds = new Set(roomMembers.map(item => item.userId));
-            return [
+            const results = [
                 ...SpaceStore.instance.enabledMetaSpaces.map(spaceKey => ({
                     section: Section.Spaces,
                     filter: [],
@@ -341,6 +341,25 @@ const SpotlightDialog: React.FC<IProps> = ({ initialText = "", initialFilter = n
                 ...(profile ? [new DirectoryMember(profile)] : []).map(toMemberResult),
                 ...publicRooms.map(toPublicRoomResult),
             ].filter(result => filter === null || result.filter.includes(filter));
+
+            // Find userIds with whom we have a DM
+            const hiddenUserIds = [...results].reduce((userIds, result) => {
+                const room: Room = result["room"];
+                if (!room) return userIds;
+                const userId = DMRoomMap.shared().getUserIdForRoomId(room.roomId);
+                if (!userId) return userIds;
+                if (room.getJoinedMemberCount() > 2) return userIds;
+
+                userIds.add(userId);
+                return userIds;
+            }, new Set<string>());
+
+            // Filter out members with whom we have a DM
+            return results.filter((result) => {
+                const userId = result["member"]?.userId;
+                if (!userId) return true;
+                return !hiddenUserIds.has(userId);
+            });
         },
         [cli, users, profile, publicRooms, filter],
     );