lib/configuration improvements

Configuration changes:
- Configuration::value return type is now [[nodiscard]]
- Configuration::value<T> is now a generic template that only works with
the exact types of the underlying std::variant
- Add Configuration::value<concept_value_t> for standard library types
compatible with the types of std::variant
- Add Configuration::shortcut<> placeholder, and QAction and
QKeySequence specializations as a convenient way to set up shortcuts
- Deprecate setShortcut
- Add Configuration::read_file convenience member that takes file path
as parameter

Format changes:
- Configuration files can now have sections, specified as [section
name]. Section names are prepended to keys. Section names cannot be
nested.
- Configuration files can now have @@include directives, causing another
file to be read as well. The included file is not treated as nested into
a section, and will overwrite values previously set.

Others:
- add some tests for libconfiguration. QAction/QKeySequence require a
QApplication be set up, so the test application may require running
xorg/wayland.

old coverage: lines: 15.6% (960 out of 6172) branches: 9.9% (1187 out of 12012)
new coverage: lines: 17.1% (1067 out of 6254) branches: 11.0% (1388 out of 12644)

1 files changed, 126 insertions, 0 deletions

diff --git a/lib/configuration/test/parser.cpp b/lib/configuration/test/parser.cpp
new file mode 100644
index 0000000..3ad64a5
--- /dev/null
+++ b/lib/configuration/test/parser.cpp
@@ -0,0 +1,126 @@
+#include "configuration.h"
+#include <QApplication>
+#include <cstdlib>
+#include <fstream>
+#include <gtest/gtest.h>
+#include <sstream>
+
+class ConfigurationTest : public ::testing::Test
+{
+protected:
+    void SetUp() override
+    {
+        conf.read_file(std::getenv("CONFIGFILE"));
+    }
+
+    Configuration conf{
+        { "name", std::string() },
+        { "over", std::string() },
+        { "other", std::string("not in cfg") }, // this entry is not in the conf file
+        { "comment", std::string() }, // commented out entry in the conf file
+        { "number", int(0) },
+        { "toggle", bool(false) },
+
+        { "main/name", std::string() },
+        { "main/number", int(0) },
+        { "main/toggle", bool(true) },
+
+        { "extra/name", std::string() },
+        { "extra/number", int(0) },
+        { "extra/toggle", bool(false) },
+    };
+
+    std::unique_ptr<Configuration> global_conf = std::make_unique<Configuration, std::initializer_list<std::pair<std::string, conf_value_t>>>({
+        { "name", std::string("global") },
+        { "number", int(123) },
+        { "toggle", bool(true) },
+
+    });
+};
+
+TEST_F(ConfigurationTest, NoSection)
+{
+    EXPECT_EQ(conf.value<std::string>("name").value(), "Top level");
+    EXPECT_EQ(conf.value<std::string>("other").value(), "not in cfg");
+    EXPECT_EQ(conf.value<std::string>("comment").value(), "");
+    EXPECT_EQ(conf.value<int>("number").value(), 12);
+    EXPECT_TRUE(conf.value<bool>("toggle").value());
+    EXPECT_FALSE(conf.value<int>("nullopt"));
+    EXPECT_FALSE(conf.value<bool>("nullopt"));
+    EXPECT_FALSE(conf.value<std::string>("nullopt"));
+}
+
+TEST_F(ConfigurationTest, TypeCasts)
+{
+    EXPECT_EQ(conf.value<std::string>("number").value(), "12");
+    EXPECT_EQ(conf.value<std::string>("toggle").value(), "true");
+    EXPECT_EQ(conf.value<std::string>("main/toggle").value(), "false");
+}
+
+TEST_F(ConfigurationTest, QtSpecialization)
+{
+    EXPECT_EQ(conf.value<QString>("name").value(), "Top level");
+    EXPECT_EQ(conf.value<QString>("number").value(), "12");
+    EXPECT_EQ(conf.value<QString>("toggle").value(), "true");
+    EXPECT_EQ(conf.value<QString>("main/toggle").value(), "false");
+    EXPECT_FALSE(conf.value<QString>("nullopt"));
+
+    EXPECT_EQ(conf.value<QStringList>("list").value(), QStringList({ "one", "two", "three", "for four" }));
+    EXPECT_FALSE(conf.value<QStringList>("nullopt"));
+}
+
+TEST_F(ConfigurationTest, QtShortcut)
+{
+    QAction action;
+    EXPECT_EQ(conf.shortcut<QAction>(action, "qt/shortcut").shortcut().toString(), "Ctrl+Q");
+    EXPECT_EQ(conf.shortcut<QAction>(action, "qt/nil").shortcut().toString(), "Ctrl+Q");
+
+    QKeySequence sequence;
+    EXPECT_EQ(conf.shortcut<QKeySequence>(sequence, "qt/shortcut").toString(), "Ctrl+Q");
+    EXPECT_EQ(conf.shortcut<QKeySequence>(sequence, "qt/nil").toString(), "Ctrl+Q");
+}
+
+TEST_F(ConfigurationTest, MainSection)
+{
+    EXPECT_EQ(conf.value<std::string>("main/name").value(), "Section Testing");
+    EXPECT_EQ(conf.value<int>("main/number").value(), 10);
+    EXPECT_FALSE(conf.value<bool>("main/toggle").value());
+}
+
+TEST_F(ConfigurationTest, ExtraSection)
+{
+    EXPECT_EQ(conf.value<std::string>("over").value(), "extra");
+    EXPECT_EQ(conf.value<std::string>("extra/name").value(), "extra section");
+    EXPECT_EQ(conf.value<int>("extra/number").value(), 12);
+    EXPECT_TRUE(conf.value<bool>("extra/toggle").value());
+}
+
+TEST_F(ConfigurationTest, GlobalInstance)
+{
+    std::stringstream output;
+
+    output << *global_conf;
+    EXPECT_EQ(output.str(), "name=global\nnumber=123\ntoggle=true\n") << "operator<< on global_conf before move";
+
+    Configuration::move_global(std::move(global_conf));
+    Configuration g;
+    EXPECT_TRUE(g.value<std::string>("name"));
+    EXPECT_EQ(g.value<std::string>("name").value(), "global");
+    EXPECT_TRUE(g.value<int>("number"));
+    EXPECT_EQ(g.value<int>("number").value(), 123);
+    EXPECT_TRUE(g.value<bool>("toggle"));
+    EXPECT_EQ(g.value<bool>("toggle").value(), true);
+    EXPECT_FALSE(g.value<std::string>("nullopt"));
+
+    output.str(std::string());
+    output << g;
+    EXPECT_EQ(output.str(), "name=global\nnumber=123\ntoggle=true\n") << "operator<< on global_conf after move";
+}
+
+int main(int argc, char **argv)
+{
+    QApplication a(argc, argv);
+
+    testing::InitGoogleTest(&argc, argv);
+    return RUN_ALL_TESTS();
+}