[SC2046] false positive from return $([ "$(tput colors)" -ge "8" ])

[SwuduSusuwu]

For bugs

• Rule Id: SC2046):
• My shellcheck version: https://github.com/SwuduSusuwu/SubStack/blob/experimental/.github/workflows/codacy.yml
• [ X ] The rule's wiki page does not already cover this (e.g. https://shellcheck.net/wiki/SC2046)
• [ X ] I tried on https://www.shellcheck.net/ and verified that this is still a problem on the latest commit

Here's a snippet or screenshot that shows the problem:

#!/bin/sh
SUSUWU_HAS_STANDARD_CONSOLE() ( #/* Usage: `if SUSUWU_HAS_STANDARD_CONSOLE; then
$(SUSUWU_SH_USE "${SUSUWU_SH_<color>}" "<message>")` */
    if command -v "tput" >/dev/null; then #if installed `ncurses-utils`
        return $([ "$(tput colors)" -ge "8" ]) #standard console
    fi
    for CONSOLE in "xterm" "xterm-color" "xterm-256color" "screen" "screen-color" "screen-256color" "tmux" "tmux-color" "tmux-256color" "linux" "rxvt" "rxvt-unicode"; do
    if [ "${TERM}" = "${CONSOLE}" ]; then
         return 0 #standard console
    fi
    done
    return 1
)

(from SwuduSusuwu/SubStack@5f57561#diff-34e56429da29b8a769483ffcd6eb3c6089937cdc157438b119ae25d2b06750beR59-R69).

Here's what shellcheck currently says:

Quote this to prevent word splitting.

Here's what I wanted or expected to see:

How to add more quotes, or "Passed".

return $("[ "$(tput colors)" -ge "8" ]") is a syntax error (outputs [ "256" -ge "8" ]: command not found), and return "$([ "$(tput colors)" -ge "8" ])" is a syntax error (outputs No command found), so do not know how to add more quotes.

[brother]

I am not sure that code does what you want it to do but the correct quoting would be the complete subshell (second line in your report).

But let's break it down to try to understand what we have.
return $([ "$(tput colors)" -ge "8" ])

The return can be dropped first, we want to control the flow in the function and end on a exit code.

Starting inside the square brackets we have a subshell excuting tput colors. It will give us a exit code to work with.
That will be compared as being either greater than or equal to 8. That comparison will leave us with either 0 or 1.

brother ~$ [ "256" -ge "8" ]
brother ~$ echo $?
0
brother ~$ [ "8" -ge "8" ]
brother ~$ echo $?
0
brother ~$ [ "1" -ge "8" ]
brother ~$ echo $?
1

The square bracket comparison will then be passed up a step to the subshell and executed. In most cases I would assume that there are no command 0 nor 1 and thus you'll have "command not found".

I think shellcheck does suggest the correct quoting in this case. I am doubting that the code presented is constructed correct.

Maybe

        if [ "$(tput colors)" -ge "8" ]; then
            return 0 #standard console
        fi
        return 1

[SwuduSusuwu]

    if [ "$(tput colors)" -ge "8" ]; then
      return 0 #standard console
    fi
    return 1

is a workaround. Too bad that is 4 lines instead of 1 (such as return $([ "$(tput colors)" -ge "8" ])) to do this.

[SwuduSusuwu]

Workaround:

test "$(tput colors)" -ge "8" 
return $?

reduces those 4 lines to 2.