Added logging of json snippets on json deserialization errors.

This commit is contained in:
Taloth Saldono 2018-07-06 21:44:15 +02:00
parent 8b8bfb9bf0
commit 0cce6b74f9
2 changed files with 87 additions and 10 deletions

View File

@ -1,5 +1,6 @@
using System;
using System.IO;
using System.Reflection;
using Newtonsoft.Json;
using Newtonsoft.Json.Converters;
using Newtonsoft.Json.Serialization;
@ -33,14 +34,63 @@ namespace NzbDrone.Common.Serializer
}
public static T Deserialize<T>(string json) where T : new()
{
try
{
return JsonConvert.DeserializeObject<T>(json, SerializerSetting);
}
catch (JsonReaderException ex)
{
throw DetailedJsonReaderException(ex, json);
}
}
public static object Deserialize(string json, Type type)
{
try
{
return JsonConvert.DeserializeObject(json, type, SerializerSetting);
}
catch (JsonReaderException ex)
{
throw DetailedJsonReaderException(ex, json);
}
}
private static JsonReaderException DetailedJsonReaderException(JsonReaderException ex, string json)
{
var lineNumber = ex.LineNumber == 0 ? 0 : (ex.LineNumber - 1);
var linePosition = ex.LinePosition;
var lines = json.Split('\n');
if (lineNumber >= 0 && lineNumber < lines.Length &&
linePosition >= 0 && linePosition < lines[lineNumber].Length)
{
var line = lines[lineNumber];
var start = Math.Max(0, linePosition - 20);
var end = Math.Min(line.Length, linePosition + 20);
var snippetBefore = line.Substring(start, linePosition - start);
var snippetAfter = line.Substring(linePosition, end - linePosition);
var message = ex.Message + " (Json snippet '" + snippetBefore + "<--error-->" + snippetAfter + "')";
// Not risking updating JSON.net from 9.x to 10.x just to get this as public ctor.
var ctor = typeof(JsonReaderException).GetConstructor(BindingFlags.NonPublic | BindingFlags.Instance, null, new Type[] { typeof(string), typeof(Exception), typeof(string), typeof(int), typeof(int) }, null);
if (ctor != null)
{
return (JsonReaderException)ctor.Invoke(new object[] { message, ex, ex.Path, ex.LineNumber, linePosition });
}
// JSON.net 10.x ctor in case we update later.
ctor = typeof(JsonReaderException).GetConstructor(BindingFlags.Public | BindingFlags.Instance, null, new Type[] { typeof(string), typeof(string), typeof(int), typeof(int), typeof(Exception) }, null);
if (ctor != null)
{
return (JsonReaderException)ctor.Invoke(new object[] { message, ex.Path, ex.LineNumber, linePosition, ex });
}
}
return ex;
}
public static bool TryDeserialize<T>(string json, out T result) where T : new()
{

View File

@ -1,3 +1,4 @@
using System;
using FluentAssertions;
using NUnit.Framework;
using NzbDrone.Common.Serializer;
@ -24,5 +25,31 @@ namespace NzbDrone.Libraries.Test.JsonTests
result.ShouldBeEquivalentTo(quality, o => o.IncludingAllRuntimeProperties());
}
[Test]
public void should_log_start_snippet_on_failure()
{
try
{
Json.Deserialize<object>("asdfl kasjd fsdfs derers");
}
catch (Exception ex)
{
ex.Message.Should().Contain("snippet '<--error-->asdfl kasjd fsdfs de'");
}
}
[Test]
public void should_log_line_snippet_on_failure()
{
try
{
Json.Deserialize<object>("{ \"a\": \r\n\"b\",\r\n \"b\": \"c\", asdfl kasjd fsdfs derers vsdfsdf");
}
catch (Exception ex)
{
ex.Message.Should().Contain("snippet ' \"b\": \"c\", asdfl <--error-->kasjd fsdfs derers v'");
}
}
}
}