feat universal: amend log format error message

Tests: протестировано CI
Fixes: https://github.com/userver-framework/userver/pull/691/files
Co-authored-by: Timur Khanipov <khanipov@gmail.com>
commit_hash:cdf0d6c2b94c6d4c776e01dee67c79b11ca5dfea

universal/src/logging/format.cpp

@@ -5,25 +5,25 @@
 #include <fmt/format.h>
 
 #include <userver/utils/assert.hpp>
+#include <userver/utils/trivial_map.hpp>
 
 USERVER_NAMESPACE_BEGIN
 
 namespace logging {
 
-Format FormatFromString(std::string_view format_str) {
-    if (format_str == "tskv") {
-        return Format::kTskv;
-    }
-
-    if (format_str == "ltsv") {
-        return Format::kLtsv;
-    }
+namespace {
+constexpr utils::TrivialBiMap kLogFormats = [](auto selector) {
+    return selector().Case("tskv", Format::kTskv).Case("ltsv", Format::kLtsv).Case("raw", Format::kRaw);
+};
 
-    if (format_str == "raw") {
-        return Format::kRaw;
-    }
+}
 
-    UINVARIANT(false, fmt::format("Unknown logging format '{}' (must be one of 'tskv', 'ltsv')", format_str));
+Format FormatFromString(std::string_view format_str) {
+    const auto result = kLogFormats.TryFindByFirst(format_str);
+    UINVARIANT(
+        result, fmt::format("Unknown logging format '{}' (must be one of {})", format_str, kLogFormats.DescribeFirst())
+    );
+    return *result;
 }
 
 }  // namespace logging