Add some tests for nix store ping

Always good to have :)

tests/local.mk

@@ -62,6 +62,7 @@ nix_tests = \
   ca/nix-copy.sh \
   eval-store.sh \
   readfile-context.sh \
+  store-ping.sh \
   why-depends.sh
   # parallel.sh
 

tests/store-ping.sh

@@ -0,0 +1,12 @@
+source common.sh
+
+STORE_INFO=$(nix store ping 2>&1)
+
+echo "$STORE_INFO" | grep "Store URL: ${NIX_REMOTE}"
+
+if isDaemonNewer "2.7pre20220126"; then
+    echo "$STORE_INFO" | grep "Version: $($NIX_DAEMON_PACKAGE/bin/nix-daemon --version)"
+fi
+
+expect 127 NIX_REMOTE=unix:$PWD/store nix store ping || \
+    fail "nix store ping on a non-existent store should fail"