Improve network error messages (#4704)

src/common/NetworkPrivate.cpp

@@ -155,7 +155,8 @@ void loadUncached(std::shared_ptr<NetworkData> &&data)
                     {
                         postToThread([data] {
                             data->onError_(NetworkResult(
-                                {}, NetworkResult::timedoutStatus));
+                                NetworkResult::NetworkError::TimeoutError, {},
+                                {}));
                         });
                     }
 
@@ -218,8 +219,9 @@ void loadUncached(std::shared_ptr<NetworkData> &&data)
                                         QString(data->payload_));
                     }
                     // TODO: Should this always be run on the GUI thread?
-                    postToThread([data, code = status.toInt(), reply] {
-                        data->onError_(NetworkResult(reply->readAll(), code));
+                    postToThread([data, status, reply] {
+                        data->onError_(NetworkResult(reply->error(), status,
+                                                     reply->readAll()));
                     });
                 }
 
@@ -238,7 +240,7 @@ void loadUncached(std::shared_ptr<NetworkData> &&data)
             auto status =
                 reply->attribute(QNetworkRequest::HttpStatusCodeAttribute);
 
-            NetworkResult result(bytes, status.toInt());
+            NetworkResult result(reply->error(), status, bytes);
 
             DebugCount::increase("http request success");
             // log("starting {}", data->request_.url().toString());
@@ -337,7 +339,8 @@ void loadCached(std::shared_ptr<NetworkData> &&data)
 
     // XXX: check if bytes is empty?
     QByteArray bytes = cachedFile.readAll();
-    NetworkResult result(bytes, 200);
+    NetworkResult result(NetworkResult::NetworkError::NoError, QVariant(200),
+                         bytes);
 
     qCDebug(chatterinoHTTP)
         << QString("%1 [CACHED] 200 %2")

src/common/NetworkResult.cpp

@@ -3,15 +3,21 @@
 #include "common/QLogging.hpp"
 
 #include <QJsonDocument>
+#include <QMetaEnum>
 #include <rapidjson/document.h>
 #include <rapidjson/error/en.h>
 
 namespace chatterino {
 
-NetworkResult::NetworkResult(const QByteArray &data, int status)
-    : data_(data)
-    , status_(status)
+NetworkResult::NetworkResult(NetworkError error, const QVariant &httpStatusCode,
+                             QByteArray data)
+    : data_(std::move(data))
+    , error_(error)
 {
+    if (httpStatusCode.isValid())
+    {
+        this->status_ = httpStatusCode.toInt();
+    }
 }
 
 QJsonObject NetworkResult::parseJson() const
@@ -59,9 +65,21 @@ const QByteArray &NetworkResult::getData() const
     return this->data_;
 }
 
-int NetworkResult::status() const
+QString NetworkResult::formatError() const
 {
-    return this->status_;
+    if (this->status_)
+    {
+        return QString::number(*this->status_);
+    }
+
+    const auto *name =
+        QMetaEnum::fromType<QNetworkReply::NetworkError>().valueToKey(
+            this->error_);
+    if (name == nullptr)
+    {
+        return QStringLiteral("unknown error (%1)").arg(this->error_);
+    }
+    return name;
 }
 
 }  // namespace chatterino

src/common/NetworkResult.hpp

@@ -2,14 +2,20 @@
 
 #include <QJsonArray>
 #include <QJsonObject>
+#include <QNetworkReply>
 #include <rapidjson/document.h>
 
+#include <optional>
+
 namespace chatterino {
 
 class NetworkResult
 {
 public:
-    NetworkResult(const QByteArray &data, int status);
+    using NetworkError = QNetworkReply::NetworkError;
+
+    NetworkResult(NetworkError error, const QVariant &httpStatusCode,
+                  QByteArray data);
 
     /// Parses the result as json and returns the root as an object.
     /// Returns empty object if parsing failed.
@@ -20,13 +26,29 @@ public:
     /// Parses the result as json and returns the document.
     rapidjson::Document parseRapidJson() const;
     const QByteArray &getData() const;
-    int status() const;
 
-    static constexpr int timedoutStatus = -2;
+    /// The error code of the reply.
+    /// In case of a successful reply, this will be NoError (0)
+    NetworkError error() const
+    {
+        return this->error_;
+    }
+
+    /// The HTTP status code if a response was received.
+    std::optional<int> status() const
+    {
+        return this->status_;
+    }
+
+    /// Formats the error.
+    /// If a reply is received, returns the HTTP status otherwise, the network error.
+    QString formatError() const;
 
 private:
     QByteArray data_;
-    int status_;
+
+    NetworkError error_;
+    std::optional<int> status_;
 };
 
 }  // namespace chatterino