From 104434182b6bf0922920b935ad8a083201fd8ed7 Mon Sep 17 00:00:00 2001
From: Andrew Casey <andrew.casey@microsoft.com>
Date: Mon, 14 Jan 2019 17:01:46 -0800
Subject: [PATCH 1/3] Harden telemetryOnOpenFile against disabled projects

As for syntax-only servers, we can't meaningfully report open-file
telemetry for projects with disabled language services.

Hopefully, a deeper fix will follow, but this solves the immediate
problem that VS disables the LS for all projects when it sees a failure
in applyChangedToOpenFiles (because it assumes the server state is
corrupt).
---
 src/server/editorServices.ts | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/server/editorServices.ts b/src/server/editorServices.ts
index cd1c69a2d67..3e062efc272 100644
--- a/src/server/editorServices.ts
+++ b/src/server/editorServices.ts
@@ -2777,7 +2777,12 @@ namespace ts.server {
                 return;
             }
 
-            const info: OpenFileInfo = { checkJs: !!scriptInfo.getDefaultProject().getSourceFile(scriptInfo.path)!.checkJsDirective };
+            const project = scriptInfo.getDefaultProject();
+            if (!project.languageServiceEnabled) {
+                return;
+            }       
+
+            const info: OpenFileInfo = { checkJs: !!project.getSourceFile(scriptInfo.path)!.checkJsDirective };
             this.eventHandler({ eventName: OpenFileInfoTelemetryEvent, data: { info } });
         }
 

From b86cb27d0b222f1cadb00e391928923c26244257 Mon Sep 17 00:00:00 2001
From: Andrew Casey <andrew.casey@microsoft.com>
Date: Mon, 14 Jan 2019 18:13:13 -0800
Subject: [PATCH 2/3] Fix trailing whitespace

---
 src/server/editorServices.ts | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/server/editorServices.ts b/src/server/editorServices.ts
index 3e062efc272..bc8197f9354 100644
--- a/src/server/editorServices.ts
+++ b/src/server/editorServices.ts
@@ -2780,7 +2780,7 @@ namespace ts.server {
             const project = scriptInfo.getDefaultProject();
             if (!project.languageServiceEnabled) {
                 return;
-            }       
+            }
 
             const info: OpenFileInfo = { checkJs: !!project.getSourceFile(scriptInfo.path)!.checkJsDirective };
             this.eventHandler({ eventName: OpenFileInfoTelemetryEvent, data: { info } });

From 3fb09630a82c3f94e47ec37515cb0733b6cfcdb5 Mon Sep 17 00:00:00 2001
From: Andrew Casey <andrew.casey@microsoft.com>
Date: Tue, 15 Jan 2019 10:55:15 -0800
Subject: [PATCH 3/3] Add regression test

---
 src/testRunner/unittests/tsserver/projects.ts | 24 +++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/src/testRunner/unittests/tsserver/projects.ts b/src/testRunner/unittests/tsserver/projects.ts
index 00941a1d3c9..3a648c9189e 100644
--- a/src/testRunner/unittests/tsserver/projects.ts
+++ b/src/testRunner/unittests/tsserver/projects.ts
@@ -103,6 +103,30 @@ namespace ts.projectSystem {
             assert.isFalse(proj3.languageServiceEnabled);
         });
 
+        it("should not crash when opening a file in a project with a disabled language service", () => {
+            const file1 = {
+                path: "/a/b/f1.js",
+                content: "let x =1;",
+                fileSize: 50 * 1024 * 1024
+            };
+            const file2 = {
+                path: "/a/b/f2.js",
+                content: "let x =1;",
+                fileSize: 100
+            };
+
+            const projName = "proj1";
+
+            const host = createServerHost([file1, file2]);
+            const projectService = createProjectService(host, { useSingleInferredProject: true }, { eventHandler: noop });
+
+            projectService.openExternalProject({ rootFiles: toExternalFiles([file1.path, file2.path]), options: {}, projectFileName: projName });
+            const proj1 = projectService.findProject(projName)!;
+            assert.isFalse(proj1.languageServiceEnabled);
+
+            assert.doesNotThrow(() => projectService.openClientFile(file2.path));
+        });
+
         describe("ignoreConfigFiles", () => {
             it("external project including config file", () => {
                 const file1 = {