Intellisense very slow on latest version

[premun]

Issue Type: Performance Issue

I have a very big project and with the latest update, any intellisense is very slow - displaying "Loading..." takes a very long time on 1.26.1.

VS Code version: Code 1.26.1 (493869e, 2018-08-16T18:38:57.434Z)
OS version: Windows_NT x64 10.0.17134

System Info

Item	Value
CPUs	Intel(R) Core(TM) i7-7820HQ CPU @ 2.90GHz (8 x 2904)
GPU Status	2d_canvas: enabled checker_imaging: disabled_off flash_3d: enabled flash_stage3d: enabled flash_stage3d_baseline: enabled gpu_compositing: enabled multiple_raster_threads: enabled_on native_gpu_memory_buffers: disabled_software rasterization: enabled video_decode: enabled video_encode: enabled webgl: enabled webgl2: enabled
Memory (System)	31.82GB (18.87GB free)
Process Argv	C:\Users\prvysoky\AppData\Local\Programs\Microsoft VS Code\Code.exe
Screen Reader	no
VM	0%

Process Info

CPU %	Mem MB	   PID	Process
    1	    81	 10960	code main
    0	    76	  8372	   shared-process
    0	   520	  9712	   window (● DiversityPicker.tsx - clients - Visual Studio Code)
    0	    82	 15528	     extensionHost
    0	  1053	  4864	       electron_node electronForkStart.js tsserver.js 
    0	    47	 13556	         electron_node typingsInstaller.js tsserver.js typesMap.js 
    0	    21	  8468	       electron_node jsonServerMain.js 
    0	    65	 17356	       electron_node tslintServer.js 
    0	    46	 16228	     searchService
    0	     3	 21912	     electron-crash-reporter
    0	    11	 22416	     watcherService 
    0	     5	 20976	       console-window-host (Windows internal process)
    0	   254	 19992	   gpu-process
    1	    70	 23432	   window (Issue Reporter)

Workspace Info

|  Window (● DiversityPicker.tsx - clients - Visual Studio Code)
|    Folder (clients): 19871 files
|      File types: js(5345) json(3925) h(2521) ts(1845) html(1520) tsx(973)
|                  png(833) java(342) cs(305) m(213)
|      Conf files: csproj(32) package.json(22) sln(6) gulp.js(3)
|                  tsconfig.json(2) project.json(1) settings.json(1)
|                  launch.json(1) tasks.json(1) tslint.json(1)
|                  webpack.config.js(1);

Extensions (8)

Extension	Author (truncated)	Version
tslint	eg2	1.0.36
vscode-git-blamer	how	1.1.2
json-to-ts	Mar	1.5.5
PowerShell	ms-	1.8.3
debugger-for-chrome	msj	4.8.2
project-snippets	reb	0.5.0
trailing-spaces	sha	0.2.11
sort-lines	Tyr	1.7.0

[vscodebot]

(Experimental duplicate detection)
Thanks for submitting this issue. Please also check if it is already covered by an existing one, like:

• Very Slow (#52013)
• Intellisense is very slow. (#56120)
• intellisense become very slow using 1.24.1 (#51819)

[mjbvz]

What type of project? Please provide more details about your project setup

[premun]

Sorry, I thought it will be in logs. It is a large TS/React project and TS intellisense is very slow. Every intellisense pop-up takes about 2-4 seconds even when about local variables.
It happens for the whole team across different MacOS & Windows and we all went back to 1.23 which fixed it.

Feel free to contact me internally for more information on [email protected].

[mjbvz]

Thanks. Please try collecting the TS Server log so we can investigate:

1. Set "typescript.tsserver.log": "verbose",
2. Restart VS Code and reproduce the problem
3. In VS Code, run the TypeScript: Open TS Server log command
4. This should open a folder with a tsserver.log file in it

Look through that log file for errors or stack traces. If you can share the log, I can also take a look to see if anything stands out

⚠️Warning: The TypeScript log may include information from your workspace, including file paths and source code. If you have any concerns about posting this publicly on Github, just let me know and we can arrange something else. On our side, we only use these logs to investigate issues like this

[premun]

I sent you the logs via Microsoft Teams as it contains sensitive data.

[mjbvz]

Closing as we follow up internally. If you have not already done so, please open an issue against typescript and send them your logs

[premun]

@mjbvz I noticed that switching TypeScript version in VS code has no effect and using TS 2.8.0 still results in slow intellisense. Is this still TS issue?

[deftomat]

@premun Hi, I'm not sure if it can helps, but can you give a try to the latest version (3.2.0-dev.20181006)? It helps us a lot. For more info see microsoft/TypeScript#26680.

[premun]

@deftomat do I need to be on VS Code insiders or install custom TS for that? I checked and 1.28.0 of VS Code comes with 3.1.1.

[deftomat]

@premun No, you just need to install TS 3.2.0-dev.20181006 or newest and use a workspace version of TypeScript in VSCode.

[premun]

@deftomat I have tried today with your version and after VS Code starts, the first call for intellisense takes about 5 seconds, then my VS Code file scrollbar jumped to the top of file and after that everything was fast and working smooth as expected. I guess it's fine then! :)