Fix tests/impl to support mock environment.

* Check if $USER is defined in clrtrust and skip checks if not.
* Skip tests relying on $USER in mock env.

clrtrust

@@ -216,6 +216,12 @@ cmd_check() {
         usr=${USER}
     fi
 
+    if [ -z ${usr} ]; then
+        # this is most likely means mock build, but even if not the checks below
+        # do not apply if the variable is not set
+        return 0
+    fi
+
     stat=($(stat -L -c "0%a %G %U" "$dir"))
     if [ $? -ne 0 ]; then
         return $EERR

test/check-negative-var-ro.bats → test/check-negative-fs-ro.bats

@@ -12,6 +12,9 @@ setup() {
 }
 
 @test "check fails when trust store cannot be written" {
+    if [ -z "${USER}" ]; then
+        skip "mock chroot environment. \$USER is not defined."
+    fi
     run $CLRTRUST check
     [ $status -ne 0 ]
     [ -n "$output" ]

test/check-negative-no-var.bats → test/check-negative-no-fs.bats

@@ -13,6 +13,9 @@ setup() {
 }
 
 @test "check fails when there's no parent for trust store" {
+    if [ -z "${USER}" ]; then
+        skip "mock chroot environment. \$USER is not defined."
+    fi
     run $CLRTRUST check
     [ $status -ne 0 ]
     [ -n "$output" ]