From 442359f5bf3563ecf765e3eb51c52fec06be1e25 Mon Sep 17 00:00:00 2001
From: Martchus <martchus@gmx.net>
Date: Sat, 29 Feb 2020 22:35:02 +0100
Subject: [PATCH] Add a function to format JSON deserialization errors

---
 lib/CMakeLists.txt         |  7 +++-
 lib/json/errorformatting.h | 78 ++++++++++++++++++++++++++++++++++++++
 2 files changed, 83 insertions(+), 2 deletions(-)
 create mode 100644 lib/json/errorformatting.h

diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index ce6b8dc..c4ec92f 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -21,7 +21,8 @@ if (RapidJSON_FOUND)
         json/reflector-boosthana.h
         json/reflector-chronoutilities.h
         json/serializable.h
-        json/errorhandling.h)
+        json/errorhandling.h
+        json/errorformatting.h)
     list(APPEND TEST_SRC_FILES tests/jsonreflector.cpp tests/jsonreflector-boosthana.cpp
          tests/jsonreflector-chronoutilities.cpp)
 endif ()
@@ -53,4 +54,6 @@ include(Doxygen)
 include(ConfigHeader)
 
 # export target name so the generator can link against it
-set(${META_PROJECT_VARNAME_UPPER}_TARGET_NAME "${META_TARGET_NAME}" PARENT_SCOPE)
+set(${META_PROJECT_VARNAME_UPPER}_TARGET_NAME
+    "${META_TARGET_NAME}"
+    PARENT_SCOPE)
diff --git a/lib/json/errorformatting.h b/lib/json/errorformatting.h
new file mode 100644
index 0000000..33e5fe1
--- /dev/null
+++ b/lib/json/errorformatting.h
@@ -0,0 +1,78 @@
+#ifndef REFLECTIVE_RAPIDJSON_JSON_ERROR_FORMATTING_H
+#define REFLECTIVE_RAPIDJSON_JSON_ERROR_FORMATTING_H
+
+/*!
+ * \file errorformatting.h
+ * \brief Contains helper functions to format errors when deserializing JSON files.
+ */
+
+#include "./errorhandling.h"
+
+#include <c++utilities/conversion/stringbuilder.h>
+
+#include <string_view>
+
+namespace ReflectiveRapidJSON {
+
+inline std::string_view jsonTypeToString(JsonType jsonType)
+{
+    switch (jsonType) {
+    case ReflectiveRapidJSON::JsonType::Null:
+        return "null";
+    case ReflectiveRapidJSON::JsonType::Number:
+        return "number";
+    case ReflectiveRapidJSON::JsonType::Bool:
+        return "bool";
+    case ReflectiveRapidJSON::JsonType::String:
+        return "string";
+    case ReflectiveRapidJSON::JsonType::Array:
+        return "array";
+    case ReflectiveRapidJSON::JsonType::Object:
+        return "object";
+    default:
+        return "?";
+    }
+}
+
+inline std::string formatJsonDeserializationError(const JsonDeserializationError &error)
+{
+    using namespace CppUtilities;
+    std::string_view errorKind;
+    std::string additionalInfo;
+    switch (error.kind) {
+    case JsonDeserializationErrorKind::TypeMismatch:
+        errorKind = "type mismatch";
+        additionalInfo = ": expected \"" % jsonTypeToString(error.expectedType) % "\", got \"" % jsonTypeToString(error.actualType) + '\"';
+        break;
+    case JsonDeserializationErrorKind::ArraySizeMismatch:
+        errorKind = "array size mismatch";
+        break;
+    case JsonDeserializationErrorKind::ConversionError:
+        errorKind = "conversion error";
+        break;
+    case JsonDeserializationErrorKind::UnexpectedDuplicate:
+        errorKind = "unexpected duplicate";
+        break;
+    case JsonDeserializationErrorKind::InvalidVariantObject:
+        errorKind = "invalid variant object";
+        break;
+    case JsonDeserializationErrorKind::InvalidVariantIndex:
+        errorKind = "invalid variant index";
+        break;
+    default:
+        errorKind = "semantic error";
+    }
+    if (error.record && error.member) {
+        return errorKind % " within record \"" % error.record % "\" and member \"" % error.member % '\"' + additionalInfo;
+    } else if (error.record && error.index != JsonDeserializationError::noIndex) {
+        return errorKind % " within record \"" % error.record % "\" and index \"" % error.index % '\"' + additionalInfo;
+    } else if (error.record) {
+        return errorKind % " within record \"" % error.record % '\"' + additionalInfo;
+    } else {
+        return errorKind % " in document" + additionalInfo;
+    }
+}
+
+} // namespace ReflectiveRapidJSON
+
+#endif // REFLECTIVE_RAPIDJSON_JSON_ERROR_FORMATTING_H