Language Services should recognize transitive dependencies for intellisense

[KrisSodroski]

Issue Type: Bug

Since npm 7, transitive dependencies are honored when installing packages. Given I have the following structure:

{
  "name": "app",
  "version": "1.0.0",
  "dependencies": {
    "a": "^1.0.0",
    "b": "^1.0.0"
  }
}

{
  "name": "b",
  "version": "1.0.0",
  "peerDependencies": {
    "c": "^2.0.0"
  },
 "devDependencies": {
    "c": "^2.0.0"
  }
}

When installing app, npm installed module b, and through peer dependencies of modules b, also installs module c.

Unfortunately, when doing so, typescript's language services no longer help with imports/typing from module c.

To fix this, app can installed module c directly, but this brings us back full circle to the days when package.json's were full of useless dependencies.

VS Code version: Code 1.68.1 (30d9c6c, 2022-06-14T12:48:58.283Z)
OS version: Windows_NT x64 10.0.17763
Restricted Mode: No

System Info

Item	Value
CPUs	Intel(R) Xeon(R) CPU E3-1275 v5 @ 3.60GHz (8 x 3600)
GPU Status	2d_canvas: unavailable_software canvas_oop_rasterization: disabled_off direct_rendering_display_compositor: disabled_off_ok gpu_compositing: disabled_software multiple_raster_threads: enabled_on oop_rasterization: disabled_off opengl: disabled_off rasterization: disabled_software raw_draw: disabled_off_ok skia_renderer: enabled_on video_decode: disabled_software video_encode: disabled_software vulkan: disabled_off webgl: unavailable_software webgl2: unavailable_software
Load (avg)	undefined
Memory (System)	9.51GB (2.56GB free)
Process Argv	--folder-uri file:///c%3A/TFS/Emerald/PermissionsManagement --crash-reporter-id 6655adb3-2fb8-47fd-84a4-43e264305df8
Screen Reader	no
VM	0%

Extensions (14)

Extension	Author (truncated)	Version
vscode-sql-formatter	adp	1.4.4
ng-template	Ang	14.1.0
gitlens	eam	12.1.2
vscode-scss	mrm	0.10.0
python	ms-	2022.10.1
vscode-pylance	ms-	2022.7.40
jupyter	ms-	2022.6.1201981810
jupyter-keymap	ms-	1.0.0
jupyter-renderers	ms-	1.0.9
powershell	ms-	2022.7.2
vscode-typescript-tslint-plugin	ms-	1.3.4
microsoft-office-add-in-debugger	mso	0.3.0
vscode-xml	red	0.21.2022062916
vscode-scss-formatter	sib	2.4.3

A/B Experiments

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[vscodenpa]

Thanks for creating this issue! It looks like you may be using an old version of VS Code, the latest stable release is 1.69.2. Please try upgrading to the latest version and checking whether this issue remains.

Happy Coding!

[KrisSodroski]

I have tested on 1.69.2 and experience the same.

[IllusionMH]

That's intended behavior of TS - you shouldn't rely on packages that aren't specified in your package.json as they are implementation details of your actual dependency b and can be changes/removed at any moment.

Direct peerDependencies should work microsoft/TypeScript#38923

See microsoft/TypeScript#35560 and other

[vscodenpa]

The described behavior is how it is expected to work. If you disagree, please explain what is expected and what is not in more detail. See also our issue reporting guidelines.

Happy Coding!