Displaying "invisibles" in Xcode editor does not render all invisible characters

Number:rdar://FB9835960 Date Originated:20220107
Status:Open Resolved:
Product:Xcode Product Version:13.2.1
Classification:Incorrect/Unexpected Behavior Reproducible:Yes
Turning on display of invisible characters using Editor → Invisibles does not render effectively invisible characters, such as "ㅤ" (HANGUL FILLER Unicode: U+3164, UTF-8: E3 85 A4). This makes obfuscated or malformed code hard to detect.

This is code I was given:
func ㅤㅤㅤ(ㅤ: Float, ㅤㅤ : Float, ㅤㅤㅤ: Float) -> Float {
    return (1-ㅤㅤㅤ)*ㅤ + ㅤㅤㅤ*ㅤㅤ

Turn on invisibles in the Xcode editor and note how there is no indication of a function name between func and the parenthesis or before the parameter types.

The editor should indicate that there are invisible HANGUL FILLER characters in the source code.

The source code does not indicate that there are any zero-width characters in the code.


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