A proportional sans-serif font with extra left padding in capital case letters. And wider a space glyph.
Here’s a side-by-side with one of the most readable monospace typeface.

- Remove the padding around
===so it can be used for a solid long line - Make
"longer, so it's easier to read e.g.'"foo"', also add more horizontal spacing. - Larger return ligature
- Ligature for
>>=<<=+=-=*= - Ligature for
//closer together - Ligature for
... - Ligature for
../(for directories ../../) - Ligature for
() - Ligature for
export(not so fancy as return but more visible) - Ligature for
throw(not so fancy as return but more visible) - Ligature for
thenin the bold font (but to make lighter and thinner) - Ligature for
this(smaller) - Ligature for
asyncandawait(maybe italic) - More space around
/for imports (bold and regular) - More space around
.(but not much more) - More space around
(and) - More space before
M
- Try another font, because this one is too large (byte size). I guess it’s because I naively made the bold font by offsetting the normal one.
- Alternatively, in monospaced fonts, condense capital case letters.
Modified with FontForge.