Yaml2JsonNode fails json->yaml->json roundtrip

[amis92]

Environment

• Nuget Package: Yaml2JsonNode
• Nuget Version: 1.2.0
• OS: Linux
• .Net Target: .NET 7

Describe the bug

When converting JSON string it's always converted to Any-style of Yaml Scalar.

Converting a JSON with a number within a string prevents roundtripping to yaml and again JSON, because a string (that looks like a number) in original JSON becomes an actual JSON number scalar when converting back from YAML.

Additionally, when creating repro, I've discovered that json.ToYamlNode doesn't handle null values within JSON.

To Reproduce

See fiddle: https://dotnetfiddle.net/FfxJlu

using System;
using System.Linq;
using System.Text.Json.Nodes;
using Yaml2JsonNode;
					
var jsonText = """
  {"foo":123,"foz":"123","bar":1.23,"baz": "1.23"}
  """;
var json = JsonNode.Parse(jsonText);
var yaml = json.ToYamlNode();
var yamlText = YamlSerializer.Serialize(yaml: yaml);

var jsonRoundtripped = YamlSerializer.Parse(yamlText).Single().ToJsonNode();
var jsonRoundText = jsonRoundtripped.ToJsonString();

Console.WriteLine("# jsonText:");
Console.WriteLine(jsonText);
Console.WriteLine();
Console.WriteLine("# yamlText:");
Console.WriteLine(yamlText);
Console.WriteLine("# jsonRoundText:");
Console.WriteLine(jsonRoundText);

Diff what is and what I'd want:

# jsonText:
{"foo":123,"foz":"123","bar":1.23,"baz": "1.23"}

# yamlText:
foo: 123
- foz: 123
+ foz: '123'
bar: 1.23
- baz: 1.23
+ baz: '1.23'

# jsonRoundText:
- {"foo":123,"foz":123,"bar":1.23,"baz":1.23}
+ {"foo":123,"foz":"123","bar":1.23,"baz":"1.23"}

Expected behavior

A json converted into YAML and back to JSON keeps the scalar types. That'd mean that the YAML scalar nodes are created as single- or double-quoted string-scalars for decimal- or bool- parsable strings.

Additional context

Generally, the conversion from YAML to JSON handles type differentiation quite well, but opposite direction isn't as thorough.

[amis92]

And also thank you for that package in general. I've found it very useful!

[gregsdennis]

Thanks for the reproduction. That helps a lot. In the future, could you also add the output you get vs the output you expect, please?

I'll get to work on this.

[gregsdennis]

Didn't mean to close this.

[amis92]

Added output vs expected!

[gregsdennis]

I see what you mean. Numbers are interpreted as strings from the YAML back to JSON.

This is actually a consequence of YAML and hwo YamlDotNet handles parsing more than anything with this library. With YAML in general it's not always possible/efficient to tell if a value is intended to be a string or a number.

I'll see if I can do anything about it. Ultimately, I'm limited to how that project is parsing the YAML.

[gregsdennis]

You can actually see this is the case with this code:

var yamlValue = new YamlScalarNode("123");
var yamlKey = new YamlScalarNode("a");

var yamlObject = new YamlMappingNode(new Dictionary<YamlNode, YamlNode>
{
	[yamlKey] = yamlValue
});

var builder = new SerializerBuilder();
var serializer = builder.Build();
using var writer = new StringWriter();
serializer.Serialize(writer, yamlObject);
var text = writer.ToString();

Console.WriteLine(text);

This outputs

a: 123

I've tried all of the serializer configuration methods that are offered, and I don't see any that will serialize numeric strings (or even just all strings) as quoted strings.

When this is read back by the YAML parser, it interprets the value as a number.

[gregsdennis]

I think this is probably the best match to what you're wanting.

aaubry/YamlDotNet#315

You might try the workaround. You can configure the serializer as part of the .Serialize() method:

var text = YamlSerialize.Serialize(yaml,
    builder => builder.WithEventEmitter(nextEmitter => new QuoteSurroundingEventEmitter(nextEmitter)));

I'm not sure this is something that I'm ready to put in this lib, though.

[amis92]

Couldn't setting YamlScalar.Style to Quoted work when mapping from JSON ode to YamlNode?

[gregsdennis]

Yep. That worked! I didn't even know that was a thing I could set. Nice call.

I'll have an update out soon.