chore: warn when parsing environment variable fails (#3904)

* chore: warn when parsing environment variable fails

* doc: update changelog

CHANGELOG.md

@@ -26,6 +26,7 @@
 - Minor: Removed total views from the usercard, as Twitch no longer updates the number. (#3792)
 - Minor: Add Quick Switcher item to open a channel in a new popup window. (#3828)
 - Minor: Reduced GIF frame window from 30ms to 20ms, causing fewer frame skips in animated emotes. (#3886)
+- Minor: Warn when parsing an environment variable fails. (#3904)
 - Bugfix: Fix crash that can occur when closing and quickly reopening a split, then running a command. (#3852)
 - Bugfix: Connection to Twitch PubSub now recovers more reliably. (#3643, #3716)
 - Bugfix: Fix crash that can occur when changing channels. (#3799)

src/CMakeLists.txt

@@ -332,6 +332,7 @@ set(SOURCE_FILES
         util/StreamerMode.hpp
         util/Twitch.cpp
         util/Twitch.hpp
+        util/TypeName.hpp
         util/WindowsHelper.cpp
         util/WindowsHelper.hpp
 

src/common/Env.cpp

@@ -1,11 +1,38 @@
 #include "common/Env.hpp"
 
+#include "common/QLogging.hpp"
+#include "util/TypeName.hpp"
+
 #include <QVariant>
 
 namespace chatterino {
 
 namespace {
 
+    template <typename T>
+    void warn(const char *envName, T defaultValue)
+    {
+        auto *envString = std::getenv(envName);
+        if (!envString)
+        {
+            // This function is not supposed to be used for non-existant
+            // environment variables.
+            return;
+        }
+
+        const auto typeName = QString::fromStdString(
+            std::string(type_name<decltype(defaultValue)>()));
+
+        qCWarning(chatterinoEnv).noquote()
+            << QStringLiteral(
+                   "Cannot parse value '%1' of environment variable '%2' "
+                   "as a %3, reverting to default value '%4'")
+                   .arg(envString)
+                   .arg(envName)
+                   .arg(typeName)
+                   .arg(defaultValue);
+    }
+
     QString readStringEnv(const char *envName, QString defaultValue)
     {
         auto envString = std::getenv(envName);
@@ -28,6 +55,10 @@ namespace {
             {
                 return val;
             }
+            else
+            {
+                warn(envName, defaultValue);
+            }
         }
 
         return defaultValue;

src/common/QLogging.cpp

@@ -13,6 +13,7 @@ Q_LOGGING_CATEGORY(chatterinoBttv, "chatterino.bttv", logThreshold);
 Q_LOGGING_CATEGORY(chatterinoCache, "chatterino.cache", logThreshold);
 Q_LOGGING_CATEGORY(chatterinoCommon, "chatterino.common", logThreshold);
 Q_LOGGING_CATEGORY(chatterinoEmoji, "chatterino.emoji", logThreshold);
+Q_LOGGING_CATEGORY(chatterinoEnv, "chatterino.env", logThreshold);
 Q_LOGGING_CATEGORY(chatterinoFfzemotes, "chatterino.ffzemotes", logThreshold);
 Q_LOGGING_CATEGORY(chatterinoHelper, "chatterino.helper", logThreshold);
 Q_LOGGING_CATEGORY(chatterinoHotkeys, "chatterino.hotkeys", logThreshold);

src/common/QLogging.hpp

@@ -9,6 +9,7 @@ Q_DECLARE_LOGGING_CATEGORY(chatterinoBttv);
 Q_DECLARE_LOGGING_CATEGORY(chatterinoCache);
 Q_DECLARE_LOGGING_CATEGORY(chatterinoCommon);
 Q_DECLARE_LOGGING_CATEGORY(chatterinoEmoji);
+Q_DECLARE_LOGGING_CATEGORY(chatterinoEnv);
 Q_DECLARE_LOGGING_CATEGORY(chatterinoFfzemotes);
 Q_DECLARE_LOGGING_CATEGORY(chatterinoHelper);
 Q_DECLARE_LOGGING_CATEGORY(chatterinoHotkeys);

src/util/TypeName.hpp

@@ -0,0 +1,34 @@
+#pragma once
+
+#include <string_view>
+
+namespace chatterino {
+
+// Adapted from: https://stackoverflow.com/a/56766138.
+// NOTE: Relies on the "magic" prefixes and suffixes. There are implementations
+// that attempt to manually detect these (linked in the SO answer above) but
+// they seemed too complex for the scope we have here.
+template <typename T>
+constexpr auto type_name()
+{
+    std::string_view name, prefix, suffix;
+#ifdef __clang__
+    name = __PRETTY_FUNCTION__;
+    prefix = "auto chatterino::type_name() [T = ";
+    suffix = "]";
+#elif defined(__GNUC__)
+    name = __PRETTY_FUNCTION__;
+    prefix = "constexpr auto chatterino::type_name() [with T = ";
+    suffix = "]";
+#elif defined(_MSC_VER)
+    name = __FUNCSIG__;
+    prefix = "auto __cdecl chatterino::type_name<";
+    suffix = ">(void)";
+#endif
+    name.remove_prefix(prefix.size());
+    name.remove_suffix(suffix.size());
+
+    return name;
+}
+
+}  // namespace chatterino