UnquotedStringTypeDeserialization_RegularNumbers test fails for floating point numbers

[jhgbrt]

After fresh checkout, when I build and run the tests on my system, these tests fail for the floating point inputs:

---

 UnquotedStringTypeDeserialization_RegularNumbers(expected: 1,7976931348623157E+308)
 Source: DeserializerTest.cs line 237
 Duration: < 1 ms

Message: 
Assert.Equal() Failure: Values differ
Expected: 1,7976931348623157E+308
Actual: 1,7976931348623157E+308

Stack Trace: 
DeserializerTest.UnquotedStringTypeDeserialization_RegularNumbers(Object expected) line 259
InvokeStub_DeserializerTest.UnquotedStringTypeDeserialization_RegularNumbers(Object, Span`1)
MethodBaseInvoker.InvokeWithOneArg(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)

---

 UnquotedStringTypeDeserialization_RegularNumbers(expected: -1,7976931348623157E+308)
 Source: DeserializerTest.cs line 237
 Duration: < 1 ms

Message: 
Assert.Equal() Failure: Values differ
Expected: -1,7976931348623157E+308
Actual: -1,7976931348623157E+308

Stack Trace: 
DeserializerTest.UnquotedStringTypeDeserialization_RegularNumbers(Object expected) line 259
InvokeStub_DeserializerTest.UnquotedStringTypeDeserialization_RegularNumbers(Object, Span`1)
MethodBaseInvoker.InvokeWithOneArg(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)

---

 UnquotedStringTypeDeserialization_RegularNumbers(expected: 3,40282347E+38)
 Source: DeserializerTest.cs line 237
 Duration: < 1 ms

Message: 
Assert.Equal() Failure: Values differ
Expected: 3,40282347E+38
Actual: 3,4028235E+38

Stack Trace: 
DeserializerTest.UnquotedStringTypeDeserialization_RegularNumbers(Object expected) line 259
InvokeStub_DeserializerTest.UnquotedStringTypeDeserialization_RegularNumbers(Object, Span`1)
MethodBaseInvoker.InvokeWithOneArg(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)

---

 UnquotedStringTypeDeserialization_RegularNumbers(expected: -3,40282347E+38)
 Source: DeserializerTest.cs line 237
 Duration: 2 ms

Message: 
Assert.Equal() Failure: Values differ
Expected: -3,40282347E+38
Actual: -3,4028235E+38

Stack Trace: 
DeserializerTest.UnquotedStringTypeDeserialization_RegularNumbers(Object expected) line 259
InvokeStub_DeserializerTest.UnquotedStringTypeDeserialization_RegularNumbers(Object, Span`1)
MethodBaseInvoker.InvokeWithOneArg(Object obj, BindingFlags invokeAttr, Binder binder, Object[] parameters, CultureInfo culture)

[jhgbrt]

seems related to culture settings; changing var yaml = $"Value: {expected}"; to var yaml = FormattableString.Invariant($"Value: {expected}"); makes the tests pass.

Culprit is

                else if (Regex.IsMatch(v, @"^[-+]?(\.[0-9]+|[0-9]+(\.[0-9]*)?)([eE][-+]?[0-9]+)?$")) //regular number

This never matches when decimal separator is not a point, and $"{expected}" will generate a string with comma on system with comma-based decimals.

Conclusion:

• fix this by changing the test to use FormattableString.Invariant
• (optional) in the future, support also non-invariant cultures for data type inference of floating point numbers

[EdwardCooke]

Yaml is pretty consistent in what a number is in its format which is using a period instead of a comma. There’s a yamlformatter which has all the stuff built in to it to be compliant with spec.

[jhgbrt]

Yaml is pretty consistent in what a number is in its format which is using a period instead of a comma. There’s a yamlformatter which has all the stuff built in to it to be compliant with spec.

Sure, but the point is that this test fails on a machine that has a locale configured with comma as a decimal separator.

[EdwardCooke]

This has been a problem in the past there’s a docker image that should test for that though. What’s your local. Should be something like en_US

[jhgbrt]

[edited for more clarification]

The test fails if you run it in on a pc that is set to another locale, that is the whole point.

What the test currently does:

var yaml = $"Value: {expected}";

This generates a serialized expected string value using the system locale settings. In this case, for single/double values that means it generates the wrong expected value, with comma instead of point as decimal separator (for systems with 'wrong' locale).

Fix: replace that line with

var yaml = FormattableString.Invariant($"Value: {expected}");

makes sure that the expected value is always correct, regardless of system settings, while still testing what is intended (deserialization according to the spec).

Hope this makes it more clear?