tests: Simplify shell exit status negation;

* tests/guix-archive.sh, tests/guix-build-branch.sh, tests/guix-build.sh,
tests/guix-daemon.sh, tests/guix-download.sh, tests/guix-environment.sh,
tests/guix-gc.sh, tests/guix-git-authenticate.sh, tests/guix-graph.sh,
tests/guix-hash.sh, tests/guix-lint.sh, tests/guix-pack-relocatable.sh,
tests/guix-pack.sh, tests/guix-package-aliases.sh, tests/guix-package-net.sh,
tests/guix-package.sh: Use the shell '!' keyword to negate command exit status
in place of 'if ...; then false; else true; fi'

1 files changed, 3 insertions, 4 deletions

diff --git a/tests/guix-graph.sh b/tests/guix-graph.sh
index ccb4933c88..666660ab4b 100644
--- a/tests/guix-graph.sh
+++ b/tests/guix-graph.sh
@@ -60,7 +60,7 @@ guix graph -t references guile-bootstrap | grep guile-bootstrap
 guix graph -e '(@ (gnu packages bootstrap) %bootstrap-guile)' \
     | grep guile-bootstrap
 
-if guix graph -e +; then false; else true; fi
+! guix graph -e +
 
 # Try passing store file names.
 
@@ -77,14 +77,13 @@ cmp "$tmpfile1" "$tmpfile2"
 # Try package transformation options.
 guix graph git | grep 'label = "openssl'
 guix graph git --with-input=openssl=libressl | grep 'label = "libressl'
-if guix graph git --with-input=openssl=libressl | grep 'label = "openssl'
-then false; else true; fi
+! guix graph git --with-input=openssl=libressl | grep 'label = "openssl'
 
 # Try --load-path
 guix graph -L $module_dir dummy | grep 'label = "dummy'
 
 # Displaying shortest paths (or lack thereof).
-if guix graph --path emacs vim; then false; else true; fi
+! guix graph --path emacs vim
 
 path="\
 emacs