diff --git a/src/server/editorServices.ts b/src/server/editorServices.ts
index 117887d7611ac..4bbd1b7d6b88a 100644
--- a/src/server/editorServices.ts
+++ b/src/server/editorServices.ts
@@ -5,6 +5,7 @@ namespace ts.server {
 
     // tslint:disable variable-name
     export const ProjectsUpdatedInBackgroundEvent = "projectsUpdatedInBackground";
+    export const SurveyReady = "surveyReady";
     export const LargeFileReferencedEvent = "largeFileReferenced";
     export const ConfigFileDiagEvent = "configFileDiag";
     export const ProjectLanguageServiceStateEvent = "projectLanguageServiceState";
@@ -17,6 +18,11 @@ namespace ts.server {
         data: { openFiles: string[]; };
     }
 
+    export interface SurveyReady {
+        eventName: typeof SurveyReady;
+        data: { surveyId: string; };
+    }
+
     export interface LargeFileReferencedEvent {
         eventName: typeof LargeFileReferencedEvent;
         data: { file: string; fileSize: number; maxFileSize: number; };
@@ -98,7 +104,7 @@ namespace ts.server {
         readonly checkJs: boolean;
     }
 
-    export type ProjectServiceEvent = LargeFileReferencedEvent | ProjectsUpdatedInBackgroundEvent | ConfigFileDiagEvent | ProjectLanguageServiceStateEvent | ProjectInfoTelemetryEvent | OpenFileInfoTelemetryEvent;
+    export type ProjectServiceEvent = LargeFileReferencedEvent | SurveyReady | ProjectsUpdatedInBackgroundEvent | ConfigFileDiagEvent | ProjectLanguageServiceStateEvent | ProjectInfoTelemetryEvent | OpenFileInfoTelemetryEvent;
 
     export type ProjectServiceEventHandler = (event: ProjectServiceEvent) => void;
 
@@ -456,6 +462,9 @@ namespace ts.server {
         /** Tracks projects that we have already sent telemetry for. */
         private readonly seenProjects = createMap<true>();
 
+        /** Tracks projects that we have already sent survey events for. */
+        private readonly seenSurveyProjects = createMap<true>();
+
         /*@internal*/
         readonly watchFactory: WatchFactory<WatchType, Project>;
 
@@ -657,6 +666,14 @@ namespace ts.server {
             this.eventHandler(event);
         }
 
+        /* @internal */
+        sendSurveyReadyEvent(surveyId: string) {
+            if (!this.eventHandler) {
+                return;
+            }
+            this.eventHandler({ eventName: SurveyReady, data: { surveyId } });
+        }
+
         /* @internal */
         sendLargeFileReferencedEvent(file: string, fileSize: number) {
             if (!this.eventHandler) {
@@ -1471,6 +1488,20 @@ namespace ts.server {
             return project;
         }
 
+        /*@internal*/
+        sendSurveyReady(project: ExternalProject | ConfiguredProject): void {
+            if (this.seenSurveyProjects.has(project.projectName)) {
+                return;
+            }
+
+            if (project.getCompilerOptions().checkJs !== undefined) {
+                const name = "checkJs";
+                this.logger.info(`Survey ${name} is ready`);
+                this.sendSurveyReadyEvent(name);
+                this.seenSurveyProjects.set(project.projectName, true);
+            }
+        }
+
         /*@internal*/
         sendProjectTelemetry(project: ExternalProject | ConfiguredProject): void {
             if (this.seenProjects.has(project.projectName)) {
diff --git a/src/server/project.ts b/src/server/project.ts
index ff2c504a54a0a..59c1e082039c8 100644
--- a/src/server/project.ts
+++ b/src/server/project.ts
@@ -1366,6 +1366,7 @@ namespace ts.server {
                     result = super.updateGraph();
             }
             this.projectService.sendProjectTelemetry(this);
+            this.projectService.sendSurveyReady(this);
             return result;
         }
 
@@ -1565,6 +1566,7 @@ namespace ts.server {
         updateGraph() {
             const result = super.updateGraph();
             this.projectService.sendProjectTelemetry(this);
+            this.projectService.sendSurveyReady(this);
             return result;
         }
 
diff --git a/src/server/protocol.ts b/src/server/protocol.ts
index f8e94085c479e..89417082b4a72 100644
--- a/src/server/protocol.ts
+++ b/src/server/protocol.ts
@@ -2436,6 +2436,18 @@ namespace ts.server.protocol {
         openFiles: string[];
     }
 
+    export type SurveyReadyEventName = "surveyReady";
+
+    export interface SurveyReadyEvent extends Event {
+        event: SurveyReadyEventName;
+        body: SurveyReadyEventBody;
+    }
+
+    export interface SurveyReadyEventBody {
+        /** Name of the survey. This is an internal machine- and programmer-friendly name */
+        surveyId: string;
+    }
+
     export type LargeFileReferencedEventName = "largeFileReferenced";
     export interface LargeFileReferencedEvent extends Event {
         event: LargeFileReferencedEventName;
diff --git a/src/server/session.ts b/src/server/session.ts
index 8d2fbe9e190a1..97541d1995552 100644
--- a/src/server/session.ts
+++ b/src/server/session.ts
@@ -572,6 +572,10 @@ namespace ts.server {
                         diagnostics: bakedDiags
                     }, "configFileDiag");
                     break;
+                case SurveyReady:
+                    const { surveyId } = event.data;
+                    this.event<protocol.SurveyReadyEventBody>({ surveyId }, "surveyReady");
+                    break;
                 case ProjectLanguageServiceStateEvent: {
                     const eventName: protocol.ProjectLanguageServiceStateEventName = "projectLanguageServiceState";
                     this.event<protocol.ProjectLanguageServiceStateEventBody>({
diff --git a/src/testRunner/unittests/tsserverProjectSystem.ts b/src/testRunner/unittests/tsserverProjectSystem.ts
index b99a2d9fe999e..6c98db8f0a0cf 100644
--- a/src/testRunner/unittests/tsserverProjectSystem.ts
+++ b/src/testRunner/unittests/tsserverProjectSystem.ts
@@ -2846,7 +2846,7 @@ namespace ts.projectSystem {
             const session = createSession(host, {
                 canUseEvents: true,
                 eventHandler: e => {
-                    if (e.eventName === server.ConfigFileDiagEvent || e.eventName === server.ProjectsUpdatedInBackgroundEvent || e.eventName === server.ProjectInfoTelemetryEvent || e.eventName === server.OpenFileInfoTelemetryEvent || e.eventName === server.LargeFileReferencedEvent) {
+                    if (e.eventName === server.ConfigFileDiagEvent || e.eventName === server.ProjectsUpdatedInBackgroundEvent || e.eventName === server.ProjectInfoTelemetryEvent || e.eventName === server.OpenFileInfoTelemetryEvent || e.eventName === server.LargeFileReferencedEvent || e.eventName === server.SurveyReady) {
                         return;
                     }
                     assert.equal(e.eventName, server.ProjectLanguageServiceStateEvent);
@@ -3496,6 +3496,121 @@ namespace ts.projectSystem {
             }
         });
 
+        function createSessionWithEventHandler(host: TestServerHost) {
+            const surveyEvents: server.SurveyReady[] = [];
+            const session = createSession(host, {
+                eventHandler: e => {
+                    if (e.eventName === server.SurveyReady) {
+                        surveyEvents.push(e);
+                    }
+                }
+            });
+
+            return { session, verifySurveyReadyEvent };
+
+            function verifySurveyReadyEvent(numberOfEvents: number) {
+                assert.equal(surveyEvents.length, numberOfEvents);
+                const expectedEvents = numberOfEvents === 0 ? [] : [{
+                    eventName: server.SurveyReady,
+                    data: { surveyId: "checkJs" }
+                }];
+                assert.deepEqual(surveyEvents, expectedEvents);
+            }
+        }
+
+        it("doesn't log an event when checkJs isn't set", () => {
+            const projectRoot = "/user/username/projects/project";
+            const file: File = {
+                path: `${projectRoot}/src/file.ts`,
+                content: "export var y = 10;"
+            };
+            const tsconfig: File = {
+                path: `${projectRoot}/tsconfig.json`,
+                content: JSON.stringify({ compilerOptions: { } }),
+            };
+            const host = createServerHost([file, tsconfig]);
+            const { session, verifySurveyReadyEvent } = createSessionWithEventHandler(host);
+            const service = session.getProjectService();
+            openFilesForSession([file], session);
+            checkNumberOfProjects(service, { configuredProjects: 1 });
+            const project = service.configuredProjects.get(tsconfig.path)!;
+            checkProjectActualFiles(project, [file.path, tsconfig.path]);
+
+            verifySurveyReadyEvent(0);
+        });
+
+        it("logs an event when checkJs is set", () => {
+            const projectRoot = "/user/username/projects/project";
+            const file: File = {
+                path: `${projectRoot}/src/file.ts`,
+                content: "export var y = 10;"
+            };
+            const tsconfig: File = {
+                path: `${projectRoot}/tsconfig.json`,
+                content: JSON.stringify({ compilerOptions: { checkJs: true } }),
+            };
+            const host = createServerHost([file, tsconfig]);
+            const { session, verifySurveyReadyEvent } = createSessionWithEventHandler(host);
+            openFilesForSession([file], session);
+
+            verifySurveyReadyEvent(1);
+        });
+
+        it("logs an event when checkJs is set, only the first time", () => {
+            const projectRoot = "/user/username/projects/project";
+            const file: File = {
+                path: `${projectRoot}/src/file.ts`,
+                content: "export var y = 10;"
+            };
+            const rando: File = {
+                path: `/rando/calrissian.ts`,
+                content: "export function f() { }"
+            };
+            const tsconfig: File = {
+                path: `${projectRoot}/tsconfig.json`,
+                content: JSON.stringify({ compilerOptions: { checkJs: true } }),
+            };
+            const host = createServerHost([file, tsconfig]);
+            const { session, verifySurveyReadyEvent } = createSessionWithEventHandler(host);
+            openFilesForSession([file], session);
+
+            verifySurveyReadyEvent(1);
+
+            closeFilesForSession([file], session);
+            openFilesForSession([rando], session);
+            openFilesForSession([file], session);
+
+            verifySurveyReadyEvent(1);
+        });
+
+        it("logs an event when checkJs is set after closing and reopening", () => {
+            const projectRoot = "/user/username/projects/project";
+            const file: File = {
+                path: `${projectRoot}/src/file.ts`,
+                content: "export var y = 10;"
+            };
+            const rando: File = {
+                path: `/rando/calrissian.ts`,
+                content: "export function f() { }"
+            };
+            const tsconfig: File = {
+                path: `${projectRoot}/tsconfig.json`,
+                content: JSON.stringify({ }),
+            };
+            const host = createServerHost([file, tsconfig]);
+            const { session, verifySurveyReadyEvent } = createSessionWithEventHandler(host);
+            openFilesForSession([file], session);
+
+            verifySurveyReadyEvent(0);
+
+            closeFilesForSession([file], session);
+            openFilesForSession([rando], session);
+            host.writeFile(tsconfig.path, JSON.stringify({ compilerOptions: { checkJs: true } }));
+            openFilesForSession([file], session);
+
+            verifySurveyReadyEvent(1);
+        });
+
         describe("CompileOnSaveAffectedFileListRequest with and without projectFileName in request", () => {
             const projectRoot = "/user/username/projects/myproject";
             const core: File = {
diff --git a/tests/baselines/reference/api/tsserverlibrary.d.ts b/tests/baselines/reference/api/tsserverlibrary.d.ts
index 5e992f3847a8b..ccf65bb705e85 100644
--- a/tests/baselines/reference/api/tsserverlibrary.d.ts
+++ b/tests/baselines/reference/api/tsserverlibrary.d.ts
@@ -7460,6 +7460,15 @@ declare namespace ts.server.protocol {
          */
         openFiles: string[];
     }
+    type SurveyReadyEventName = "surveyReady";
+    interface SurveyReadyEvent extends Event {
+        event: SurveyReadyEventName;
+        body: SurveyReadyEventBody;
+    }
+    interface SurveyReadyEventBody {
+        /** Name of the survey. This is an internal machine- and programmer-friendly name */
+        surveyId: string;
+    }
     type LargeFileReferencedEventName = "largeFileReferenced";
     interface LargeFileReferencedEvent extends Event {
         event: LargeFileReferencedEventName;
@@ -8201,6 +8210,7 @@ declare namespace ts.server {
 declare namespace ts.server {
     const maxProgramSizeForNonTsFiles: number;
     const ProjectsUpdatedInBackgroundEvent = "projectsUpdatedInBackground";
+    const SurveyReady = "surveyReady";
     const LargeFileReferencedEvent = "largeFileReferenced";
     const ConfigFileDiagEvent = "configFileDiag";
     const ProjectLanguageServiceStateEvent = "projectLanguageServiceState";
@@ -8212,6 +8222,12 @@ declare namespace ts.server {
             openFiles: string[];
         };
     }
+    interface SurveyReady {
+        eventName: typeof SurveyReady;
+        data: {
+            surveyId: string;
+        };
+    }
     interface LargeFileReferencedEvent {
         eventName: typeof LargeFileReferencedEvent;
         data: {
@@ -8290,7 +8306,7 @@ declare namespace ts.server {
     interface OpenFileInfo {
         readonly checkJs: boolean;
     }
-    type ProjectServiceEvent = LargeFileReferencedEvent | ProjectsUpdatedInBackgroundEvent | ConfigFileDiagEvent | ProjectLanguageServiceStateEvent | ProjectInfoTelemetryEvent | OpenFileInfoTelemetryEvent;
+    type ProjectServiceEvent = LargeFileReferencedEvent | SurveyReady | ProjectsUpdatedInBackgroundEvent | ConfigFileDiagEvent | ProjectLanguageServiceStateEvent | ProjectInfoTelemetryEvent | OpenFileInfoTelemetryEvent;
     type ProjectServiceEventHandler = (event: ProjectServiceEvent) => void;
     interface SafeList {
         [name: string]: {
@@ -8409,6 +8425,8 @@ declare namespace ts.server {
         readonly syntaxOnly?: boolean;
         /** Tracks projects that we have already sent telemetry for. */
         private readonly seenProjects;
+        /** Tracks projects that we have already sent survey events for. */
+        private readonly seenSurveyProjects;
         constructor(opts: ProjectServiceOptions);
         toPath(fileName: string): Path;
         private loadTypesMap;