Incorrect syntax colouring of YAML multi-line values containing colons

[itowlson]

Issue Type: Bug

Note: This was originally reported on the Kubernetes extension at vscode-kubernetes-tools/vscode-kubernetes-tools#639, and traced upstream to the Red Hat YAML extension at redhat-developer/vscode-yaml#242, but it looks like it affects all YAML files even without those extensions being installed, and appears to be down to the VS Code built-in YAML highlighter at https://github.com/microsoft/vscode/blob/master/extensions/yaml/syntaxes/yaml.tmLanguage.json.

The syntax highlighting of multi-line values containing colon characters doesn't look right. For example, consider the following YAML:

foo:
  bar: |
    set_header 'Server: '
    set_header 'Access-Control-Allow-Methods: GET, PUT, POST, DELETE, PATCH, OPTIONS'
    set_header 'Access-Control-Allow-Origin: https://snip'

Here's how this gets highlighted:

Note that the first line of the multiline value gets 'key' colouring (blue) up to the colon, then the closing quote and start of next line get 'value" (brown) colouring until the next quote, then key again until the colon, then value...

If I remove the colons, everything in the multi-line value is correctly coloured brown.

I tried this in an online YAML parser and it treated the multi-line section as a single value, so I think this should be valid - the colons shouldn't be being handled as key-value separators.

VS Code version: Code 1.39.2 (6ab5985, 2019-10-15T15:35:18.241Z)
OS version: Windows_NT x64 10.0.18363

System Info

Item	Value
CPUs	Intel(R) Core(TM) i7-7600U CPU @ 2.80GHz (4 x 2904)
GPU Status	2d_canvas: enabled flash_3d: enabled flash_stage3d: enabled flash_stage3d_baseline: enabled gpu_compositing: enabled multiple_raster_threads: enabled_on native_gpu_memory_buffers: disabled_software oop_rasterization: disabled_off protected_video_decode: enabled rasterization: enabled skia_deferred_display_list: disabled_off skia_renderer: disabled_off surface_synchronization: enabled_on video_decode: enabled viz_display_compositor: disabled_off webgl: enabled webgl2: enabled
Load (avg)	undefined
Memory (System)	15.85GB (2.04GB free)
Process Argv
Screen Reader	no
VM	22%

Extensions (10)

Extension	Author (truncated)	Version
gitlens	eam	10.1.1
EditorConfig	Edi	0.14.2
tslint	eg2	1.0.44
vscode-peacock	joh	3.1.6
vscode-docker	ms-	0.8.1
vscode-kubernetes-tools	ms-	1.0.6
remote-wsl	ms-	0.39.9
azure-account	ms-	0.8.6
azurerm-vscode-tools	msa	0.8.0
vscode-yaml	red	0.5.3

[alexr00]

Looks like this is the upstream issue textmate/yaml.tmbundle#17

[itowlson]

The trouble with closing this as an upstream issue is that the last comment in that upstream issue is them requesting help from the VS Code team: "Since @infininight has kindly explained the issue in a very detailed way, maybe someone familiar with VSCode would be willing to take a look at it :) It seems we're stuck without some help. Sorry for tagging you out of the blue @alexandrudima @bpasero, is there a chance you could take a quick look at this issue (or tag someone who could)? Would be very much appreciated!" So it sounds like Code is waiting for a fix from upstream, while upstream is appealing to Code to do the fix!

How do we break this circle?

[alexr00]

From what I understand from textmate/yaml.tmbundle#17 (comment), this is a limitation of using textmate. There's not much to be done about that other than maybe #77140 will help.