tests: add case_insensitive_less test

make case_insensitive_less "transparent" so you can use std::string_view
for lookups.

Author: ericwa

common/cmdlib.cc

@@ -126,11 +126,6 @@ bool case_insensitive_equal::operator()(const std::string &l, const std::string
     return Q_strcasecmp(l.c_str(), r.c_str()) == 0;
 }
 
-bool case_insensitive_less::operator()(const std::string &l, const std::string &r) const noexcept
-{
-    return Q_strcasecmp(l.c_str(), r.c_str()) < 0;
-}
-
 // membuf
 
 membuf::membuf(void *base, size_t size, std::ios_base::openmode which)

include/common/cmdlib.hh

@@ -50,7 +50,9 @@ struct case_insensitive_equal
 
 struct case_insensitive_less
 {
-    bool operator()(const std::string &l, const std::string &r) const noexcept;
+    using is_transparent = void;
+
+    bool operator()(std::string_view a, std::string_view b) const noexcept { return Q_strcasecmp(a, b) < 0; }
 };
 
 /**

tests/test_common.cc

@@ -7,6 +7,7 @@
 
 #include <cstdint>
 #include <filesystem>
+#include <string_view>
 #include <common/bspfile.hh>
 #include <common/bspfile_q1.hh>
 #include <common/bspfile_q2.hh>
@@ -33,6 +34,25 @@ TEST(common, stringIStartsWith)
     EXPECT_FALSE(string_istarts_with("asdf", "ASDFX"));
 }
 
+TEST(common, caseInsensitiveLess)
+{
+    using namespace std::string_view_literals;
+
+    std::map<std::string, int, case_insensitive_less> testmap;
+
+    testmap["abc"] = 1;
+    testmap["def"] = 2;
+    testmap["ghi"] = 3;
+
+    EXPECT_EQ(3, testmap.size());
+
+    EXPECT_EQ(1, testmap.find("ABC"sv)->second);
+    EXPECT_EQ(2, testmap.find("DEF"sv)->second);
+    EXPECT_EQ(3, testmap.find("GHI"sv)->second);
+
+    EXPECT_EQ(testmap.end(), testmap.find("A"));
+}
+
 TEST(common, q1Contents)
 {
     auto *game_q1 = bspver_q1.game;