test: add unit test for Association class

Problem: There is no unit testing framework that exists for the class
(and eventually methods and functions) for the Association class.

Begin to add some unit tests for this class.

src/Makefile.am

@@ -47,7 +47,8 @@ fairness_libweighted_tree_la_CXXFLAGS = \
 TESTS = \
 	weighted_tree_test01.t \
 	data_reader_db_test01.t \
-	data_writer_db_test01.t
+	data_writer_db_test01.t \
+	accounting_test01.t
 check_PROGRAMS = $(TESTS)
 
 TEST_EXTENSIONS = .t
@@ -94,6 +95,14 @@ data_writer_db_test01_t_LDADD = \
 	fairness/libweighted_tree.la \
 	common/libtap/libtap.la
 
+accounting_test01_t_SOURCES = \
+	plugins/test/accounting_test01.cpp \
+	plugins/accounting.cpp \
+	plugins/accounting.hpp
+accounting_test01_t_CXXFLAGS = $(AM_CXXFLAGS) -I$(top_srcdir)
+accounting_test01_t_LDADD = \
+	common/libtap/libtap.la
+
 noinst_PROGRAMS = \
 	cmd/flux-account-update-fshare \
 	cmd/flux-account-shares

src/plugins/test/accounting_test01.cpp

@@ -0,0 +1,100 @@
+/************************************************************\
+ * Copyright 2024 Lawrence Livermore National Security, LLC
+ * (c.f. AUTHORS, NOTICE.LLNS, COPYING)
+ *
+ * This file is part of the Flux resource manager framework.
+ * For details, see https://github.com/flux-framework.
+ *
+ * SPDX-License-Identifier: LGPL-3.0
+\************************************************************/
+
+extern "C" {
+#if HAVE_CONFIG_H
+#include "config.h"
+#endif
+}
+
+#include <iostream>
+#include <fstream>
+#include <vector>
+#include <map>
+#include <string>
+
+#include "src/plugins/accounting.hpp"
+#include "src/common/libtap/tap.h"
+
+// define a test users map to run tests on
+std::map<int, std::map<std::string, Association>> users;
+std::map<int, std::string> users_def_bank;
+
+
+/*
+ * helper function to add a user/bank to the users map
+ */
+void add_user_to_map (
+                std::map<int, std::map<std::string, Association>> &users,
+                int userid,
+                const std::string& bank,
+                Association a)
+{
+    // insert user to users map
+    users[userid][bank] = {
+        a.bank_name,
+        a.fairshare,
+        a.max_run_jobs,
+        a.cur_run_jobs,
+        a.max_active_jobs,
+        a.cur_active_jobs,
+        a.held_jobs,
+        a.queues,
+        a.queue_factor,
+        a.active
+    };
+}
+
+
+/*
+ * helper function to add test users to the users map
+ */
+void initialize_map (
+    std::map<int, std::map<std::string, Association>> &users)
+{
+    Association user1 = {"bank_A", 0.5, 5, 0, 7, 0, {}, {}, 0, 1};
+    Association user2 = {"bank_A", 0.5, 5, 0, 7, 0, {}, {}, 0, 1};
+
+    add_user_to_map (users, 1001, "bank_A", user1);
+    users_def_bank[1001] = "bank_A";
+
+    // purposely do not add user2 to the def_bank_map
+    add_user_to_map (users, 1002, "bank_A", user2);
+}
+
+
+// ensure we can access a user/bank in the users map
+static void test_direct_map_access (
+    std::map<int, std::map<std::string, Association>> &users)
+{
+    ok (users[1001]["bank_A"].bank_name == "bank_A", 
+        "a user/bank from users map can be accessed directly");
+}
+
+
+int main (int argc, char* argv[])
+{
+    // declare the number of tests that we plan to run
+    plan (1);
+
+    // add users to the test map
+    initialize_map (users);
+
+    test_direct_map_access (users);
+
+    // indicate we are done testing
+    done_testing ();
+
+    return EXIT_SUCCESS;
+}
+
+/*
+ * vi:tabstop=4 shiftwidth=4 expandtab
+ */