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 +110,20 @@ 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.get(".mx_Spinner").should("not.exist");
+        cy.spotlightResults().should("have.length", 1);
+        cy.spotlightResults().eq(0).should("contain", name);
+        cy.spotlightResults().eq(0).click();
+    }).then(() => {
+        cy.roomHeaderName().should("contain", name);
+        cy.get(".mx_RoomSublist[aria-label=People]").should("contain", name);
+    });
+});
+
 describe("Spotlight", () => {
     let synapse: SynapseInstance;
 
@@ -319,6 +334,23 @@ 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);
+            cy.get(".mx_Spinner").should("not.exist");
+            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

@@ -320,8 +320,25 @@ const SpotlightDialog: React.FC<IProps> = ({ initialText = "", initialFilter = n
     );
     const possibleResults = useMemo<Result[]>(
         () => {
-            const roomMembers = findVisibleRoomMembers(cli);
-            const roomMemberIds = new Set(roomMembers.map(item => item.userId));
+            const roomResults = findVisibleRooms(cli).map(toRoomResult);
+            // If we already have a DM with the user we're looking for, we will
+            // show that DM instead of the user themselves
+            const alreadyAddedUserIds = roomResults.reduce((userIds, result) => {
+                const userId = DMRoomMap.shared().getUserIdForRoomId(result.room.roomId);
+                if (!userId) return userIds;
+                if (result.room.getJoinedMemberCount() > 2) return userIds;
+                userIds.add(userId);
+                return userIds;
+            }, new Set<string>());
+            const userResults = [...findVisibleRoomMembers(cli), ...users].reduce((userResults, user) => {
+                // Make sure we don't have any user more than once
+                if (alreadyAddedUserIds.has(user.userId)) return userResults;
+                alreadyAddedUserIds.add(user.userId);
+
+                userResults.push(toMemberResult(user));
+                return userResults;
+            }, []);
+
             return [
                 ...SpaceStore.instance.enabledMetaSpaces.map(spaceKey => ({
                     section: Section.Spaces,
@@ -335,9 +352,8 @@ const SpotlightDialog: React.FC<IProps> = ({ initialText = "", initialFilter = n
                         SpaceStore.instance.setActiveSpace(spaceKey);
                     },
                 })),
-                ...findVisibleRooms(cli).map(toRoomResult),
-                ...roomMembers.map(toMemberResult),
-                ...users.filter(item => !roomMemberIds.has(item.userId)).map(toMemberResult),
+                ...roomResults,
+                ...userResults,
                 ...(profile ? [new DirectoryMember(profile)] : []).map(toMemberResult),
                 ...publicRooms.map(toPublicRoomResult),
             ].filter(result => filter === null || result.filter.includes(filter));