assert success in `_send_email`

I added `_send_email_unchecked` which performs no check so we can still
use the helper for situations where we check for failure, and
`_send_email` is a wrapper for `_send_mail_unchecked` with an additional
`assert_success`.

I also went through the tests and adjusted them where necessary.

test/helper/sending.bash

@@ -15,6 +15,10 @@
 # itself. The `--data` parameter expects a relative path from `emails/`
 # where the contents will be implicitly provided to `swaks` via STDIN.
 #
+# This functions performs **no** implicit `assert_success` to check whether
+# the e-mail transaction was successful. If this is not desirable, use
+# `_send_email`.
+#
 # ## Attention
 #
 # This function assumes `CONTAINER_NAME` to be properly set (to the container
@@ -23,7 +27,7 @@
 # This function will just send the email in an "asynchronous" fashion, i.e. it will
 # send the email but it will not make sure the mail queue is empty after the mail
 # has been sent.
-function _send_email() {
+function _send_email_unchecked() {
   [[ -v CONTAINER_NAME ]] || return 1
 
   # Parameter defaults common to our testing needs:
@@ -57,6 +61,29 @@ function _send_email() {
   done
 
   _run_in_container_bash "swaks --server ${SERVER} --port ${PORT} --ehlo ${EHLO} --from ${FROM} --to ${TO} ${ADDITIONAL_SWAKS_OPTIONS[*]} ${FINAL_SWAKS_OPTIONS[*]}"
+# Sends a mail from localhost (127.0.0.1) to a container. To send
+# a custom email, create a file at `test/files/<TEST FILE>`,
+# and provide `<TEST FILE>` as an argument to this function.
+#
+# Parameters include all options that one can supply to `swaks`
+# itself. The `--data` parameter expects a relative path from `emails/`
+# where the contents will be implicitly provided to `swaks` via STDIN.
+#
+# This functions performs an implicit `assert_success` to check whether
+# the e-mail transaction was successful. If this is not desirable, use
+# `_send_email_unchecked`.
+#
+# ## Attention
+#
+# This function assumes `CONTAINER_NAME` to be properly set (to the container
+# name the command should be executed in)!
+#
+# This function will just send the email in an "asynchronous" fashion, i.e. it will
+# send the email but it will not make sure the mail queue is empty after the mail
+# has been sent.
+function _send_email() {
+  _send_email_unchecked "${@}"
+  assert_success
 }
 
 # Like `_send_email` with two major differences:

test/tests/parallel/set1/dovecot/dovecot_quotas.bats

@@ -226,11 +226,8 @@ function teardown_file() { _default_teardown ; }
 
   # send some big emails
   _send_email --to 'quotauser@otherdomain.tld' --data 'quota-exceeded'
-  assert_success
   _send_email --to 'quotauser@otherdomain.tld' --data 'quota-exceeded'
-  assert_success
   _send_email --to 'quotauser@otherdomain.tld' --data 'quota-exceeded'
-  assert_success
   # check for quota warn message existence
   run _repeat_until_success_or_timeout 20 _exec_in_container grep -R 'Subject: quota warning' /var/mail/otherdomain.tld/quotauser/new/
   assert_success

test/tests/parallel/set1/dovecot/dovecot_sieve.bats

@@ -27,10 +27,8 @@ function setup_file() {
 
   # Single mail sent from 'spam@spam.com' that is handled by User (relocate) and Global (copy) sieves for user1:
   _send_email --data 'sieve/spam-folder'
-  assert_success
   # Mail for user2 triggers the sieve-pipe:
   _send_email --to 'user2@otherdomain.tld' --data 'sieve/pipe'
-  assert_success
 
   _wait_for_empty_mail_queue_in_container
 }

test/tests/parallel/set1/dovecot/mailbox_format_dbox.bats

@@ -27,7 +27,6 @@ function teardown() { _default_teardown ; }
   _wait_for_smtp_port_in_container
 
   _send_email --data 'existing/user1'
-  assert_success
   _wait_for_empty_mail_queue_in_container
 
   # Mail received should be stored as `u.1` (one file per message)
@@ -49,7 +48,6 @@ function teardown() { _default_teardown ; }
   _wait_for_smtp_port_in_container
 
   _send_email --data 'existing/user1'
-  assert_success
   _wait_for_empty_mail_queue_in_container
 
   # Mail received should be stored in `m.1` (1 or more messages)

test/tests/parallel/set1/dovecot/special_use_folders.bats

@@ -15,7 +15,6 @@ function teardown_file() { _default_teardown ; }
 
 @test 'normal delivery works' {
   _send_email --data 'existing/user1'
-  assert_success
   _count_files_in_directory_in_container /var/mail/localhost.localdomain/user1/new 1
 }
 

test/tests/parallel/set1/spam_virus/clamav.bats

@@ -26,7 +26,6 @@ function setup_file() {
   _wait_for_service postfix
   _wait_for_smtp_port_in_container
   _send_email --from 'virus@external.tld' --data 'amavis/virus'
-  assert_success
   _wait_for_empty_mail_queue_in_container
 }
 

test/tests/parallel/set1/spam_virus/disabled_clamav_spamassassin.bats

@@ -19,7 +19,6 @@ function setup_file() {
   _wait_for_smtp_port_in_container
 
   _send_email --data 'existing/user1'
-  assert_success
   _wait_for_empty_mail_queue_in_container
 }
 

test/tests/parallel/set1/spam_virus/fail2ban.bats

@@ -74,7 +74,7 @@ function teardown_file() {
   CONTAINER1_IP=$(_get_container_ip "${CONTAINER1_NAME}")
   # Trigger a ban by failing to login twice:
   for _ in {1..2}; do
-    CONTAINER_NAME=${CONTAINER2_NAME} _send_email \
+    CONTAINER_NAME=${CONTAINER2_NAME} _send_email_unchecked \
       --server "${CONTAINER1_IP}" \
       --port 465 \
       --auth PLAIN \

test/tests/parallel/set1/spam_virus/postgrey_enabled.bats

@@ -51,7 +51,7 @@ function teardown_file() { _default_teardown ; }
   _reload_postfix
 
   # Send test mail (it should fail to deliver):
-  _send_email --from 'user@external.tld' --port 25 --data 'postgrey'
+  _send_email_unchecked --from 'user@external.tld' --port 25 --data 'postgrey'
   assert_failure
   assert_output --partial 'Recipient address rejected: Delayed by Postgrey'
 
@@ -68,7 +68,6 @@ function teardown_file() { _default_teardown ; }
   sleep 3
   # Retry delivering test mail (it should be trusted this time):
   _send_email --from 'user@external.tld' --port 25 --data 'postgrey'
-  assert_success
 
   # Confirm postgrey permitted delivery (triplet is now trusted):
   _should_have_log_entry \

test/tests/parallel/set1/spam_virus/postscreen.bats

@@ -56,10 +56,8 @@ function teardown_file() {
 @test "should successfully pass postscreen and get postfix greeting message (respecting postscreen_greet_wait time)" {
   # Configure `send_email()` to send from the mail client container (CONTAINER2_NAME) via ENV override,
   # mail is sent to the DMS server container (CONTAINER1_NAME) via `--server` parameter:
-  CONTAINER_NAME=${CONTAINER2_NAME} _send_email --server "${CONTAINER1_IP}" --port 25 --data 'postscreen'
+  # TODO: Use _send_email when proper resolution of domain names is possible:
-  # NOTE: Cannot assert_success due to sender address not being resolvable.
+  CONTAINER_NAME=${CONTAINER2_NAME} _send_email_unchecked --server "${CONTAINER1_IP}" --port 25 --data 'postscreen'
-  # TODO: Uncomment when proper resolution of domain names is possible:
-  # assert_success
 
   # TODO: Prefer this approach when `_send_email_and_get_id()` can support separate client and server containers:
   # local MAIL_ID=$(_send_email_and_get_id --port 25 --data 'postscreen')

test/tests/parallel/set3/mta/privacy.bats

@@ -30,7 +30,6 @@ function teardown_file() { _default_teardown ; }
     --auth-user user1@localhost.localdomain \
     --auth-password mypassword \
     --data 'privacy'
-  assert_success
 
   _run_until_success_or_timeout 120 _exec_in_container_bash '[[ -d /var/mail/localhost.localdomain/user1/new ]]'
   assert_success

test/tests/parallel/set3/mta/smtp_delivery.bats

@@ -75,7 +75,8 @@ function setup_file() {
   _send_email --to test123@localhost.localdomain --data 'existing/regexp-alias-local'
 
   # Required for 'rejects mail to unknown user':
-  _send_email --to nouser@localhost.localdomain --data 'non-existing-user'
+  _send_email_unchecked --to nouser@localhost.localdomain --data 'non-existing-user'
+  assert_failure
   # Required for 'redirects mail to external aliases':
   _send_email --to bounce-always@localhost.localdomain --data 'existing/regexp-alias-external'
   _send_email --to alias2@localhost.localdomain --data 'existing/alias-local'
@@ -84,25 +85,18 @@ function setup_file() {
 
   # Required for 'delivers mail to existing account':
   _send_email --data 'existing/user1'
-  assert_success
   _send_email --to user2@otherdomain.tld
-  assert_success
   _send_email --to user3@localhost.localdomain
-  assert_success
   _send_email --to added@localhost.localdomain --data 'existing/added'
-  assert_success
   _send_email --to user1@localhost.localdomain --data 'existing/user-and-cc-local-alias'
-  assert_success
   _send_email --data 'sieve/spam-folder'
-  assert_success
   _send_email --to user2@otherdomain.tld --data 'sieve/pipe'
-  assert_success
   _run_in_container_bash 'sendmail root < /tmp/docker-mailserver-test/emails/sendmail/root-email.txt'
   assert_success
 }
 
 function _unsuccessful() {
-  _send_email --port 465 --auth "${1}" --auth-user "${2}" --auth-password wrongpassword
+  _send_email_unchecked --port 465 --auth "${1}" --auth-user "${2}" --auth-password wrongpassword
   assert_failure
   assert_output --partial 'authentication failed'
   assert_output --partial 'No authentication type succeeded'
@@ -110,7 +104,6 @@ function _unsuccessful() {
 
 function _successful() {
   _send_email --port 465 --auth "${1}" --auth-user "${2}" --auth-password mypassword --quit-after AUTH
-  assert_success
   assert_output --partial 'Authentication successful'
 }
 

test/tests/serial/mail_with_imap.bats

@@ -31,8 +31,8 @@ function teardown_file() { _default_teardown ; }
 }
 
 @test '(SASLauthd) RIMAP SMTP authentication works' {
-  _send_email \
     --auth LOGIN \
+  _send_email_unchecked \
     --auth-user user1@localhost.localdomain \
     --auth-password mypassword \
     --quit-after AUTH
@@ -45,7 +45,6 @@ function teardown_file() { _default_teardown ; }
     --auth-user user1@localhost.localdomain \
     --auth-password mypassword \
     --quit-after AUTH
-  assert_success
   assert_output --partial 'Authentication successful'
 
   _send_email \
@@ -54,7 +53,6 @@ function teardown_file() { _default_teardown ; }
     --auth-user user1@localhost.localdomain \
     --auth-password mypassword \
     --quit-after AUTH
-  assert_success
   assert_output --partial 'Authentication successful'
 }
 

test/tests/serial/mail_with_ldap.bats

@@ -326,13 +326,14 @@ function teardown() {
 @test "spoofing (with LDAP): rejects sender forging" {
   _wait_for_smtp_port_in_container_to_respond dms-test_ldap
 
-  _send_email \
     --port 465 -tlsc --auth LOGIN \
+  _send_email_unchecked \
     --auth-user some.user@localhost.localdomain \
     --auth-password secret \
     --ehlo mail \
     --from ldap@localhost.localdomain \
     --data 'auth/ldap-smtp-auth-spoofed'
+  assert_failure
   assert_output --partial 'Sender address rejected: not owned by user'
 }
 
@@ -353,20 +354,21 @@ function teardown() {
   # Template used has invalid AUTH: https://github.com/docker-mailserver/docker-mailserver/pull/3006#discussion_r1073321432
   skip 'TODO: This test seems to have been broken from the start (?)'
 
-  _send_email \
     --port 465 -tlsc --auth LOGIN \
+  _send_email_unchecked \
     --auth-user some.user.email@localhost.localdomain \
     --auth-password secret \
     --ehlo mail \
     --from randomspoofedaddress@localhost.localdomain \
     --to some.user@localhost.localdomain \
     --data 'auth/ldap-smtp-auth-spoofed-sender-with-filter-exception'
+  assert_failure
   assert_output --partial 'Sender address rejected: not owned by user'
 }
 
 @test "saslauthd: ldap smtp authentication" {
-  _send_email \
     --auth LOGIN \
+  _send_email_unchecked \
     --auth-user some.user@localhost.localdomain \
     --auth-password wrongpassword \
     --quit-after AUTH
@@ -379,7 +381,6 @@ function teardown() {
     --auth-user some.user@localhost.localdomain \
     --auth-password secret \
     --quit-after AUTH
-  assert_success
   assert_output --partial 'Authentication successful'
 
   _send_email \

test/tests/serial/tests.bats

@@ -293,8 +293,8 @@ EOF
 
   # An authenticated user cannot use an envelope sender (MAIL FROM)
   # address they do not own according to `main.cf:smtpd_sender_login_maps` lookup
-  _send_email \
     --port 465 -tlsc --auth LOGIN \
+  _send_email_unchecked \
     --auth-user added@localhost.localdomain \
     --auth-password mypassword \
     --ehlo mail \