Microsoft/vscode

[scss] Display a wrong selector preview when using sibling combinators in SCSS, Less

Open

#169,900 opened on Dec 23, 2022

View on GitHub
 (3 comments) (0 reactions) (1 assignee)TypeScript (74,848 stars) (10,221 forks)batch import
bugcss-less-scsshelp wanted

Description

Type: Bug

When using both style nesting and sibling combinators (+ and ~) in SCSS or Less, VSCode will display a wrong selector preview. I've determined that this error also occurs when no extensions are running.

For example, if writing a stylesheet like this:

.foo + .bar {
    .baz & {
        color: red;
    }
}

VSCode will display a wrong selector preview like this: image

<element class="foo">
<element class="baz">
  …
    <element class="bar">

Expect this:

<element class="baz">
  …
    <element class="foo">
    <element class="bar">

Same when using ~: image

Expect this:

<element class="baz">
  …
    <element class="foo">
    ⋮
    <element class="bar">

VS Code version: Code 1.74.2 (e8a3071ea4344d9d48ef8a4df2c097372b0c5161, 2022-12-20T10:29:14.590Z) OS version: Windows_NT x64 10.0.22621 Modes: Sandboxed: No

Item Value
CPUs Intel(R) Core(TM) i5-10210U CPU @ 1.60GHz (8 x 2112)
GPU Status 2d_canvas: enabledcanvas_oop_rasterization: disabled_offdirect_rendering_display_compositor: disabled_off_okgpu_compositing: enabledmultiple_raster_threads: enabled_onopengl: enabled_onrasterization: enabledraw_draw: disabled_off_okskia_renderer: enabled_onvideo_decode: enabledvideo_encode: enabledvulkan: disabled_offwebgl: enabledwebgl2: enabledwebgpu: disabled_off
Load (avg) undefined
Memory (System) 11.80GB (2.37GB free)
Process Argv --crash-reporter-id 76088c10-0186-42e8-9434-fc9aba83ae2a
Screen Reader no
VM 0% 
vsliv368cf:30146710
vsreu685:30147344
python383:30185418
vspor879:30202332
vspor708:30202333
vspor363:30204092
vswsl492:30256859
vslsvsres303:30308271
pythonvspyl392:30443607
vserr242cf:30382550
pythontb:30283811
vsjup518:30340749
pythonptprofiler:30281270
vshan820:30294714
vstes263cf:30335440
pythondataviewer:30285071
vscod805:30301674
binariesv615:30325510
bridge0708:30335490
bridge0723:30353136
cmake_vspar411:30581797
vsaa593:30376534
pythonvs932:30410667
cppdebug:30492333
vsclangdf:30486550
c4g48928:30535728
dsvsc012:30540252
azure-dev_surveyone:30548225
vscccc:30610679
pyindex848:30577860
nodejswelcome1:30587005
2e4cg342:30602488
gswce1:30612156
3d0df643:30613357
f6dab269:30613381
fim-prod:30623723
vscsbc:30628655

Contributor guide

Tech stack
typescriptcss
Domain
frontenddeveloper experience
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
blocked
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
SCSS/Less nestingCSS sibling combinatorsVSCode extension development
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
45
Research direction
The bug is in VSCode's CSS language service that generates selector previews. To fix it, one needs to examine the logic that resolves nested selectors with sibling combinators in SCSS/Less. The assignee has been set, so it's advisable to check if they have progress. Comments in the issue may provide additional context.