Error parsing `---` without whitespace

See complete thread for details, but basically markdown like

---
## Test 123

creates problems for us in yaml.ts export function readYamlFromMarkdown()

Discussed in https://github.com/quarto-dev/quarto-cli/discussions/3001

^{Originally posted by samarzayan October 24, 2022}
I am getting the following error exactly at the last :.
YAMLError: end of the stream or a document separator is expected at line 7, column 3:
when I use every callout block, for example:
:::{.callout-note}
Sample note.
:::
I checked online for about 2 hours but had no luck. Someone, please help.
The syntax is correct as per the Quarto docs.