Add some additional tests

tests/load.zunit

@@ -1,20 +1,20 @@
 #!/usr/bin/env zunit
 
 @test 'Test loading script with global variable sets the variable' {
-  load ./_support/script-with-global-variable;
+  load ./_support/script-with-global-variable
 
-  assert "$lost_city" equals 'Atlantis';
+  assert "$lost_city" equals 'Atlantis'
 }
 
 @test 'Test loading script with local variable does not set the variable' {
-  load ./_support/script-with-local-variable;
+  load ./_support/script-with-local-variable
 
-  assert "$lost_city" is_empty;
+  assert "$lost_city" is_empty
 }
 
 @test 'Test loading non-existent file throws error' {
-  run load ./non-existent-script;
+  run load ./non-existent-script
 
-  assert "$state" equals 1;
-  assert "$output" same_as 'File tests/./non-existent-script does not exist';
+  assert "$state" equals 1
+  assert "$output" same_as 'File tests/./non-existent-script does not exist'
 }

tests/run.zunit

@@ -0,0 +1,28 @@
+#!/usr/bin/env zunit
+
+@setup {
+  echo 'Testing setup method'
+}
+
+@teardown {
+  echo 'Testing teardown method'
+}
+
+@test 'Test successful command' {
+  run return 0
+
+  assert $state equals 0
+}
+
+@test 'Test unsuccessful command' {
+  run return 1
+
+  assert $state equals 1
+}
+
+@test 'Test non-existent command' {
+  run a-non-existent-command
+
+  assert $state equals 127
+  assert $output same_as 'run:19: command not found: a-non-existent-command'
+}

tests/setup-and-teardown.zunit

@@ -0,0 +1,27 @@
+#!/usr/bin/env zunit
+
+@setup {
+	SOME_VAR='rainbows'
+}
+
+@teardown {
+	unset SOME_VAR
+}
+
+@test 'Check value of SOME_VAR' {
+	assert $SOME_VAR same_as 'rainbows'
+}
+
+@test 'Change value of SOME_VAR' {
+	SOME_VAR='unicorns'
+	assert $SOME_VAR same_as 'unicorns'
+}
+
+@test 'Check value of SOME_VAR again' {
+	# Check will fail, because the variable was unset in
+	# the @teardown method, and then reset to 'rainbows'
+	# when @setup was run again.
+	run assert $SOME_VAR same_as 'unicorns'
+
+	assert $state equals 1
+}