Ensure teardown is always executed

src/commands/run.zsh

@@ -82,9 +82,12 @@ function _zunit_execute_test() {
       # Add an exit handler which calls the teardown function if it is
       # defined and the test exits early
       if (( \$+functions[__zunit_test_teardown] )); then
-        zshexit() {
+        TRAPEXIT() {
           __zunit_test_teardown 2>&1
         }
+        TRAPZERR() {
+          [[ -o ERR_EXIT ]] && __zunit_test_teardown 2>&1
+        }
       fi
 
       # Create some local variables to store test state in
@@ -102,14 +105,6 @@ function _zunit_execute_test() {
       # function it will be read as part of the body of this function
       ${body}
 
-      # If a teardown function is defined, run it now
-      if (( \$+functions[__zunit_test_teardown] )); then
-        __zunit_test_teardown 2>&1
-      fi
-
-      # Remove the error handler
-      zshexit() {}
-
       # Check the assertion count, and if it is 0, return
       # the warning exit code
       [[ \$_zunit_assertion_count -gt 0 ]] || return 248

tests/setup-and-teardown.zunit

@@ -1,27 +1,50 @@
 #!/usr/bin/env zunit
 
 @setup {
-	SOME_VAR='rainbows'
+  SOME_VAR='rainbows'
 }
 
 @teardown {
-	unset SOME_VAR
+  unset SOME_VAR
+  unset SOME_VAR_TEARDOWN
 }
 
 @test 'Check value of SOME_VAR' {
-	assert $SOME_VAR same_as 'rainbows'
+  assert $SOME_VAR same_as 'rainbows'
 }
 
 @test 'Change value of SOME_VAR' {
-	SOME_VAR='unicorns'
-	assert $SOME_VAR same_as 'unicorns'
+  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'
+  # 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
+  assert $state equals 1
+}
+
+@test 'Change value of SOME_VAR_TEARDOWN' {
+  SOME_VAR_TEARDOWN='rainbows'
+  run true
+
+  assert $state equals 0
+}
+
+@test 'Check value of SOME_VAR_TEARDOWN' {
+  assert $SOME_VAR_TEARDOWN is_empty
+}
+
+@test 'Change value of SOME_VAR_TEARDOWN again' {
+  SOME_VAR_TEARDOWN='rainbows'
+  run false
+
+  assert $state equals 1
+}
+
+@test 'Check value of SOME_VAR_TEARDOWN again' {
+  assert $SOME_VAR_TEARDOWN is_empty
 }