Bash Script: result of xargs assigned to variable loses all but one item

Question

I'm running a bash script that greps through files to identify tests, then it should output the results to a string and store in a variable. When the command is run on its own it echoes out all the files in a single line correctly, but when I try to assign the results to a variable, only one is shown.

This works as expected and will show a complete list of the files expected.

grep -Erli ' @IsTest| testmethod' './build/source/classes' | sed 's#.*/## ; s#.cls##' | xargs echo

However, when I do this the result of the echo is that only one file is listed in the TESTS variable

TESTS=($(grep -Erli ' @IsTest| testmethod' './build/source/classes' | sed 's#.*/## ; s#.cls##' | xargs echo))
echo $TESTS

Is there something about putting this in a variable assignment expression that is a problem? It seems to be an issue of the whitespace between each item. If I add | tr ' ' ',' to the end so it replaces whitespace with commas everything is listed, but that's not a solution I can use for this. I need a whitespace separated list of files.

Answer 1

TESTS=( ... ) is creating an array of entries.

echo $TESTS is the same as echo ${TESTS[0]}, ie, display the 1st entry in the array.

To display the entire contents of the array try echo "${TESTS[@]}" or typeset -p TESTS.

Consider:

$ TESTS=( a b c )

$ echo "$TESTS"
a

$ echo "${TESTS[0]}"
a

$ echo "${TESTS[@]}"
a b c

$ typeset -p TESTS
declare -a TESTS=([0]="a" [1]="b" [2]="c")