YamlConverterTests.cs

using SharpYaml;
using SharpYaml.Serialization;
using Xunit;
using Microsoft.OpenApi.YamlReader;
using System.IO;
using System.Text.Json.Nodes;

namespace Microsoft.OpenApi.Readers.Tests;

public class YamlConverterTests
{
    [Theory]
    [InlineData("~")]
    [InlineData("null")]
    [InlineData("Null")]
    [InlineData("NULL")]
    public void YamlNullValuesReturnNullJsonNode(string value)
    {
        // Given
        var yamlNull = new YamlScalarNode(value)
        {
            Style = ScalarStyle.Plain
        };

        // When
        var jsonNode = yamlNull.ToJsonNode();

        // Then
        Assert.Null(jsonNode);
    }

    [Fact]
    public void ToYamlNode_StringValue_NotQuotedInYaml()
    {
        // Arrange
        var json = Assert.IsType<JsonObject>(JsonNode.Parse(@"{""fooString"": ""fooStringValue""}"));

        // Act
        var yamlNode = json.ToYamlNode();
        var yamlOutput = ConvertYamlNodeToString(yamlNode);

        // Assert
        Assert.Contains("fooString: fooStringValue", yamlOutput);
        Assert.DoesNotContain("\"fooStringValue\"", yamlOutput);
        Assert.DoesNotContain("'fooStringValue'", yamlOutput);
    }

    [Fact]
    public void ToYamlNode_StringThatLooksLikeNumber_QuotedInYaml()
    {
        // Arrange
        var json = Assert.IsType<JsonObject>(JsonNode.Parse(@"{""fooStringOfNumber"": ""200""}"));

        // Act
        var yamlNode = json.ToYamlNode();
        var yamlOutput = ConvertYamlNodeToString(yamlNode);

        // Assert
        Assert.Contains("fooStringOfNumber: \"200\"", yamlOutput);
    }

    [Fact]
    public void ToYamlNode_ActualNumber_NotQuotedInYaml()
    {
        // Arrange
        var json = Assert.IsType<JsonObject>(JsonNode.Parse(@"{""actualNumber"": 200}"));

        // Act
        var yamlNode = json.ToYamlNode();
        var yamlOutput = ConvertYamlNodeToString(yamlNode);

        // Assert
        Assert.Contains("actualNumber: 200", yamlOutput);
        Assert.DoesNotContain("\"200\"", yamlOutput);
    }

    [Fact]
    public void ToYamlNode_StringThatLooksLikeDecimal_QuotedInYaml()
    {
        // Arrange
        var json = Assert.IsType<JsonObject>(JsonNode.Parse(@"{""decimalString"": ""123.45""}"));

        // Act
        var yamlNode = json.ToYamlNode();
        var yamlOutput = ConvertYamlNodeToString(yamlNode);

        // Assert
        Assert.Contains("decimalString: \"123.45\"", yamlOutput);
    }

    [Fact]
    public void ToYamlNode_ActualDecimal_NotQuotedInYaml()
    {
        // Arrange
        var json = Assert.IsType<JsonObject>(JsonNode.Parse(@"{""actualDecimal"": 123.45}"));

        // Act
        var yamlNode = json.ToYamlNode();
        var yamlOutput = ConvertYamlNodeToString(yamlNode);

        // Assert
        Assert.Contains("actualDecimal: 123.45", yamlOutput);
        Assert.DoesNotContain("\"123.45\"", yamlOutput);
    }

    [Fact]
    public void ToYamlNode_StringThatLooksLikeBoolean_QuotedInYaml()
    {
        // Arrange
        var json = Assert.IsType<JsonObject>(JsonNode.Parse(@"{""boolString"": ""true""}"));

        // Act
        var yamlNode = json.ToYamlNode();
        var yamlOutput = ConvertYamlNodeToString(yamlNode);

        // Assert
        Assert.Contains("boolString: \"true\"", yamlOutput);
    }

    [Fact]
    public void ToYamlNode_ActualBoolean_NotQuotedInYaml()
    {
        // Arrange
        var json = Assert.IsType<JsonObject>(JsonNode.Parse(@"{""actualBool"": true}"));

        // Act
        var yamlNode = json.ToYamlNode();
        var yamlOutput = ConvertYamlNodeToString(yamlNode);

        // Assert
        Assert.Contains("actualBool: true", yamlOutput);
        Assert.DoesNotContain("\"true\"", yamlOutput);
    }

    [Fact]
    public void ToYamlNode_StringThatLooksLikeNull_QuotedInYaml()
    {
        // Arrange
        var json = Assert.IsType<JsonObject>(JsonNode.Parse(@"{""nullString"": ""null""}"));

        // Act
        var yamlNode = json.ToYamlNode();
        var yamlOutput = ConvertYamlNodeToString(yamlNode);

        // Assert
        Assert.Contains("nullString: \"null\"", yamlOutput);
    }

    [Fact]
    public void ToYamlNode_MixedTypes_CorrectQuoting()
    {
        // Arrange
        var json = Assert.IsType<JsonObject>(JsonNode.Parse(@"{
            ""str"": ""hello"",
            ""numStr"": ""42"",
            ""num"": 42,
            ""boolStr"": ""false"",
            ""bool"": false
        }"));

        // Act
        var yamlNode = json.ToYamlNode();
        var yamlOutput = ConvertYamlNodeToString(yamlNode);

        // Assert
        Assert.Contains("str: hello", yamlOutput);
        Assert.Contains("numStr: \"42\"", yamlOutput);
        Assert.Contains("num: 42", yamlOutput);
        Assert.DoesNotContain("num: \"42\"", yamlOutput);
        Assert.Contains("boolStr: \"false\"", yamlOutput);
        Assert.Contains("bool: false", yamlOutput);
        Assert.DoesNotContain("bool: \"false\"", yamlOutput);
    }

    [Fact]
    public void ToYamlNode_FromIssueExample_CorrectOutput()
    {
        // Arrange - Example from issue #1951
        var json = Assert.IsType<JsonObject>(JsonNode.Parse(@"{
            ""fooString"": ""fooStringValue"",
            ""fooStringOfNumber"": ""200""
        }"));

        // Act
        var yamlNode = json.ToYamlNode();
        var yamlOutput = ConvertYamlNodeToString(yamlNode);

        // Assert
        Assert.Contains("fooString: fooStringValue", yamlOutput);
        Assert.Contains("fooStringOfNumber: \"200\"", yamlOutput);
        
        // Ensure no extra quotes on regular strings
        Assert.DoesNotContain("\"fooStringValue\"", yamlOutput);
        Assert.DoesNotContain("'fooStringValue'", yamlOutput);
    }

    [Fact]
    public void ToYamlNode_StringWithLineBreaks_PreservesLineBreaks()
    {
        // Arrange
        var json = Assert.IsType<JsonObject>(JsonNode.Parse(@"{
            ""multiline"": ""Line 1\nLine 2\nLine 3"",
            ""description"": ""This is a description\nwith line breaks\nin it""
        }"));

        // Act
        var yamlNode = json.ToYamlNode();
        var yamlOutput = ConvertYamlNodeToString(yamlNode);

        // Convert back to JSON to verify round-tripping
        var yamlStream = new YamlStream();
        using var sr = new StringReader(yamlOutput);
        yamlStream.Load(sr);
        var jsonBack = yamlStream.Documents[0].ToJsonNode();

        // Assert - line breaks should be preserved during round-trip
        var originalMultiline = json["multiline"]?.GetValue<string>();
        var roundTripMultiline = jsonBack?["multiline"]?.GetValue<string>();
        Assert.Equal(originalMultiline, roundTripMultiline);
        Assert.Contains("\n", roundTripMultiline);

        var originalDescription = json["description"]?.GetValue<string>();
        var roundTripDescription = jsonBack?["description"]?.GetValue<string>();
        Assert.Equal(originalDescription, roundTripDescription);
        Assert.Contains("\n", roundTripDescription);
    }

    private static string ConvertYamlNodeToString(YamlNode yamlNode)
    {
        using var ms = new MemoryStream();
        var yamlStream = new YamlStream(new YamlDocument(yamlNode));
        var writer = new StreamWriter(ms);
        yamlStream.Save(writer);
        writer.Flush();
        ms.Seek(0, SeekOrigin.Begin);
        var reader = new StreamReader(ms);
        return reader.ReadToEnd();
    }
}