tests: use 'test_must_be_empty' instead of 'test ! -s'

diff --git a/t/t3600-rm.sh b/t/t3600-rm.sh
index b8fbdefcdc34ffa6fb54fc1ad375a583a194fb38..b178a376c47de2dc2e8783fdbb34da628510b8b7 100755 (executable)
--- a/t/t3600-rm.sh
+++ b/t/t3600-rm.sh
@@ -382,7 +382,7 @@ test_expect_success 'rm does not complain when no .gitmodules file is found' '
        git submodule update &&
        git rm .gitmodules &&
        git rm submod >actual 2>actual.err &&
-       ! test -s actual.err &&
+       test_must_be_empty actual.err &&
        ! test -d submod &&
        ! test -f submod/.git &&
        git status -s -uno >actual &&
@@ -400,7 +400,7 @@ test_expect_success 'rm will error out on a modified .gitmodules file unless sta
        git diff-files --quiet -- submod &&
        git add .gitmodules &&
        git rm submod >actual 2>actual.err &&
-       ! test -s actual.err &&
+       test_must_be_empty actual.err &&
        ! test -d submod &&
        ! test -f submod/.git &&
        git status -s -uno >actual &&
@@ -694,7 +694,7 @@ test_expect_success 'checking out a commit after submodule removal needs manual
        test_cmp expected actual &&
        rm -rf submod &&
        git status -s -uno --ignore-submodules=none >actual &&
-       ! test -s actual
+       test_must_be_empty actual
 '
 
 test_expect_success 'rm of d/f when d has become a non-directory' '