fix: set -euo pipefail to all tests/functional

Author: Chemaclass

tests/functional/custom_asserts_test.sh

@@ -1,4 +1,5 @@
 #!/bin/bash
+set -euo pipefail
 
 function set_up() {
   _ROOT_DIR="$(dirname "${BASH_SOURCE[0]}")"

tests/functional/logic_test.sh

@@ -1,4 +1,5 @@
 #!/bin/bash
+set -euo pipefail
 
 ROOT_DIR="$(dirname "${BASH_SOURCE[0]}")"
 

tests/functional/multi_invoker_test.sh

@@ -1,4 +1,5 @@
 #!/bin/bash
+set -euo pipefail
 
 _TEST_MULTI_INVOKER_ITERATION_FILE=""
 
@@ -15,7 +16,7 @@ function tear_down_after_script() {
 function test_multi_invoker_simple() {
   local current_number="$1"
   local second_arg="$2"
-  local third_arg="$3"
+  local third_arg="${3-}"
 
   local current_iteration=0
 

tests/functional/provider_test.sh

@@ -1,4 +1,5 @@
 #!/bin/bash
+set -euo pipefail
 
 _TEST_GET_DATA_FROM_PROVIDER_ITERATION_FILE=""