Showing 115 of 117 total issues
Line exceeds maximum allowed length Open
ret += "<tr class=\"image-row\" data-key=\"#{ image["ImageKey"] }\"><td><a href=\"#{ image['WebUri'] }\"><img src=\"#{ image["ThumbnailUrl"] }\" alt=\"Thumb\"/></a><td>#{ image["Title"] }</td><td>#{ image["FileName"] }</td><td>#{ image["ImageKey"] }</td><td class=\"usage\">?</td></tr>\n"
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Prefer single quoted strings Open
$ionicons-font-family: "Ionicons" !default;
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Literal """Make asset data from all show files accessible"""
used in void context. Open
"""Make asset data from all show files accessible"""
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This cop checks for operators, variables and literals used in void context.
Example:
# bad
def some_method
some_num * 10
do_something
end
Example:
# bad
def some_method(some_var)
some_var
do_something
end
Example:
# good
def some_method
do_something
some_num * 10
end
Example:
# good
def some_method(some_var)
do_something
some_var
end
Double quote to prevent globbing and word splitting. Open
-region $AWS_REGION -config .s3deploy.yml -source dist -path v1/$DEPLOY_NAME
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Double quote to prevent globbing and word splitting.
Problematic code:
echo $1
for i in $*; do :; done # this done and the next one also applies to expanding arrays.
for i in $@; do :; done
Correct code:
echo "$1"
for i in "$@"; do :; done # or, 'for i; do'
Rationale
The first code looks like "print the first argument". It's actually "Split the first argument by IFS (spaces, tabs and line feeds). Expand each of them as if it was a glob. Join all the resulting strings and filenames with spaces. Print the result."
The second one looks like "iterate through all arguments". It's actually "join all the arguments by the first character of IFS (space), split them by IFS and expand each of them as globs, and iterate on the resulting list". The third one skips the joining part.
Quoting variables prevents word splitting and glob expansion, and prevents the script from breaking when input contains spaces, line feeds, glob characters and such.
Strictly speaking, only expansions themselves need to be quoted, but for stylistic reasons, entire arguments with multiple variable and literal parts are often quoted as one:
$HOME/$dir/dist/bin/$file # Unquoted (bad)
"$HOME"/"$dir"/dist/bin/"$file" # Minimal quoting (good)
"$HOME/$dir/dist/bin/$file" # Canonical quoting (good)
When quoting composite arguments, make sure to exclude globs and brace expansions, which lose their special meaning in double quotes: "$HOME/$dir/src/*.c"
will not expand, but "$HOME/$dir/src"/*.c
will.
Note that $( )
starts a new context, and variables in it have to be quoted independently:
echo "This $variable is quoted $(but this $variable is not)"
echo "This $variable is quoted $(and now this "$variable" is too)"
Exceptions
Sometimes you want to split on spaces, like when building a command line:
options="-j 5 -B"
make $options file
Just quoting this doesn't work. Instead, you should have used an array (bash, ksh, zsh):
options=(-j 5 -B) # ksh: set -A options -- -j 5 -B
make "${options[@]}" file
or a function (POSIX):
make_with_flags() { make -j 5 -B "$@"; }
make_with_flags file
To split on spaces but not perform glob expansion, Posix has a set -f
to disable globbing. You can disable word splitting by setting IFS=''
.
Similarly, you might want an optional argument:
debug=""
[[ $1 == "--trace-commands" ]] && debug="-x"
bash $debug script
Quoting this doesn't work, since in the default case, "$debug"
would expand to one empty argument while $debug
would expand into zero arguments. In this case, you can use an array with zero or one elements as outlined above, or you can use an unquoted expansion with an alternate value:
debug=""
[[ $1 == "--trace-commands" ]] && debug="yes"
bash ${debug:+"-x"} script
This is better than an unquoted value because the alternative value can be properly quoted, e.g. wget ${output:+ -o "$output"}
.
As always, this warning can be [[ignore]]d on a case-by-case basis.
this is especially relevant when BASH many not be available for the array work around. For example, use in eval or in command options where script has total control of the variables...
FLAGS="-av -e 'ssh -x' --delete --delete-excluded"
...
# shellcheck disable=SC2086
eval rsync $FLAGS ~/dir remote_host:dir
Notice
Original content from the ShellCheck https://github.com/koalaman/shellcheck/wiki.
Unused method argument - index
. If it's necessary, use _
or _index
as an argument name to indicate that it won't be used. Open
def generate_year(year, index)
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This cop checks for unused method arguments.
Example:
# bad
def some_method(used, unused, _unused_but_allowed)
puts used
end
Example:
# good
def some_method(used, _unused, _unused_but_allowed)
puts used
end
Double quote to prevent globbing and word splitting. Open
echo "ENVIRONMENT=${PR_NUM}" >> $GITHUB_OUTPUT
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Double quote to prevent globbing and word splitting.
Problematic code:
echo $1
for i in $*; do :; done # this done and the next one also applies to expanding arrays.
for i in $@; do :; done
Correct code:
echo "$1"
for i in "$@"; do :; done # or, 'for i; do'
Rationale
The first code looks like "print the first argument". It's actually "Split the first argument by IFS (spaces, tabs and line feeds). Expand each of them as if it was a glob. Join all the resulting strings and filenames with spaces. Print the result."
The second one looks like "iterate through all arguments". It's actually "join all the arguments by the first character of IFS (space), split them by IFS and expand each of them as globs, and iterate on the resulting list". The third one skips the joining part.
Quoting variables prevents word splitting and glob expansion, and prevents the script from breaking when input contains spaces, line feeds, glob characters and such.
Strictly speaking, only expansions themselves need to be quoted, but for stylistic reasons, entire arguments with multiple variable and literal parts are often quoted as one:
$HOME/$dir/dist/bin/$file # Unquoted (bad)
"$HOME"/"$dir"/dist/bin/"$file" # Minimal quoting (good)
"$HOME/$dir/dist/bin/$file" # Canonical quoting (good)
When quoting composite arguments, make sure to exclude globs and brace expansions, which lose their special meaning in double quotes: "$HOME/$dir/src/*.c"
will not expand, but "$HOME/$dir/src"/*.c
will.
Note that $( )
starts a new context, and variables in it have to be quoted independently:
echo "This $variable is quoted $(but this $variable is not)"
echo "This $variable is quoted $(and now this "$variable" is too)"
Exceptions
Sometimes you want to split on spaces, like when building a command line:
options="-j 5 -B"
make $options file
Just quoting this doesn't work. Instead, you should have used an array (bash, ksh, zsh):
options=(-j 5 -B) # ksh: set -A options -- -j 5 -B
make "${options[@]}" file
or a function (POSIX):
make_with_flags() { make -j 5 -B "$@"; }
make_with_flags file
To split on spaces but not perform glob expansion, Posix has a set -f
to disable globbing. You can disable word splitting by setting IFS=''
.
Similarly, you might want an optional argument:
debug=""
[[ $1 == "--trace-commands" ]] && debug="-x"
bash $debug script
Quoting this doesn't work, since in the default case, "$debug"
would expand to one empty argument while $debug
would expand into zero arguments. In this case, you can use an array with zero or one elements as outlined above, or you can use an unquoted expansion with an alternate value:
debug=""
[[ $1 == "--trace-commands" ]] && debug="yes"
bash ${debug:+"-x"} script
This is better than an unquoted value because the alternative value can be properly quoted, e.g. wget ${output:+ -o "$output"}
.
As always, this warning can be [[ignore]]d on a case-by-case basis.
this is especially relevant when BASH many not be available for the array work around. For example, use in eval or in command options where script has total control of the variables...
FLAGS="-av -e 'ssh -x' --delete --delete-excluded"
...
# shellcheck disable=SC2086
eval rsync $FLAGS ~/dir remote_host:dir
Notice
Original content from the ShellCheck https://github.com/koalaman/shellcheck/wiki.
Redundant use of Object#to_s
in interpolation. Open
"#{ @year.to_s }–#{ year_span_short[1] }"
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This cop checks for string conversion in string interpolation, which is redundant.
Example:
# bad
"result is #{something.to_s}"
Example:
# good
"result is #{something}"
TODO found Open
<!-- TODO back behavior broken, see https://github.com/turbolinks/turbolinks/issues/75 -->
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HACK found Open
// HACK, cos the thing we need to override is quite specific
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HACK found Open
// HACK correction from moving from GF Montserrat to latest
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TODO found Open
# TODO feed back into calling Jekyll plugin
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BUG found Open
# BUG: This method falls over if the number of imageIDs is large
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