test: restructure dir layout

Attempt to clarify the structure of our tests. Each test case is now
encapsulated in a script in `test/cases`. Each of these scripts should
be runnable on a pristine machine and be independent of each other. It
is up to the test-orchestractor to decide if they should be run
consequtively instance, or in parallel on separate instances. Each
script can execute several tests and call whatever helper binaries
is desired. However, each case should be assumed to always run as one.

test/cases/base_tests.sh

@@ -0,0 +1,61 @@
+#!/bin/bash
+set -euo pipefail
+
+WORKING_DIRECTORY=/usr/libexec/osbuild-composer
+TESTS_PATH=/usr/libexec/osbuild-composer-test
+
+PASSED_TESTS=()
+FAILED_TESTS=()
+
+TEST_CASES=(
+  "osbuild-weldr-tests"
+  "osbuild-dnf-json-tests"
+  "osbuild-composer-cli-tests"
+  "osbuild-auth-tests"
+)
+
+# Print out a nice test divider so we know when tests stop and start.
+test_divider () {
+    printf "%0.s-" {1..78} && echo
+}
+
+# Run a test case and store the result as passed or failed.
+run_test_case () {
+    TEST_NAME=$(basename "$1")
+    echo
+    test_divider
+    echo "🏃🏻 Running test: ${TEST_NAME}"
+    test_divider
+
+    if sudo "${1}" -test.v | tee "${WORKSPACE}"/"${TEST_NAME}".log; then
+        PASSED_TESTS+=("$TEST_NAME")
+    else
+        FAILED_TESTS+=("$TEST_NAME")
+    fi
+
+    test_divider
+    echo
+}
+
+# Change to the working directory.
+cd $WORKING_DIRECTORY
+
+# Run each test case.
+for TEST_CASE in "${TEST_CASES[@]}"; do
+    run_test_case ${TESTS_PATH}/"$TEST_CASE"
+done
+
+# Print a report of the test results.
+test_divider
+echo "😃 Passed tests:" "${PASSED_TESTS[@]}"
+echo "☹ Failed tests:" "${FAILED_TESTS[@]}"
+test_divider
+
+# Exit with a failure if tests were executed and any of them failed.
+if [ ${#PASSED_TESTS[@]} -gt 0 ] && [ ${#FAILED_TESTS[@]} -eq 0 ]; then
+    echo "🎉 All tests passed."
+    exit 0
+else
+    echo "🔥 One or more tests failed."
+    exit 1
+fi