Incorrect syntax highlight for interpolated strings

[tcNickolas]

Describe the bug

Expressions in squiggly brackets inside interpolated strings are highlighted as a string, rather than as Q# code fragments.

To Reproduce

For example, the string

$"Vertex = {vertex} judged{(not expectedResult[vertex]) ? "" | " not"} weakly colored for coloring = {coloring}, edges = {edges}"

is highlighted as follows (on GitHub as well):

Expected behavior

I expect the highlighting to be similar to C# interpolated strings, which highlight the squiggly brackets and the expressions inside them as code snippets; so the first not highlighted in blue (keyword), the second one in red (string), and the variables and the ternary operator in black (regular code).

System information

• Visual Studio Community 2019, 16.11.3 + QDK 0.18.2109.162713, and
• VS Code, + QDK 0.19.2109.165653
  (From filing this issue it looks like the same problem happens for GitHub syntax highlight)