JsonElement.WriteAsValue does not support scientific notation with decimal separator

[ghord]

I encountered the issue where following code throws:

var test = JsonDocument.Parse("{ \"test\" : 6.5e-5 }").RootElement;

using(var stream = new MemoryStream())
{
       var writer = new Utf8JsonWriter(stream);
       //throws System.ArgumentException: 'e' is an invalid end of a number. Expected a delimiter.
       test.WriteAsValue(writer);       
}

Tested on .net core 3 preview5 and preview6.

[bartonjs]

https://github.com/dotnet/corefx/blob/7a9c2ab617229faad613fa5554b298df388f6fb7/src/System.Text.Json/src/System/Text/Json/Writer/JsonWriterHelper.cs#L177-L181

Says that . and e are exclusive, which is (in retrospect) obviously wrong.

[vicrdguez]

Hi
I would like to take this one, is it up for grab?

[bartonjs]

@vicrdguez All yours :)

[vicrdguez]

Added to principal branch, Commit 589cd355
Tell me if something is not correct

[ericstj]

/cc @tannergooding since this is numerics related

[bartonjs]

@vicrdguez I left some comments on the commit. In addition to fixing the functional errors there should be test cases added for

• Positive decimal positive scientific: 6.022e23
• Positive decimal negative scientific: 6.022e-23
• Negative decimal positive scientific: -6.022e23
• Negative decimal negative scientific: -6.022e-23

I know there's a 1e400 case (positive/positive no-decimal), making sure that we also have something like -1e400 and 1e-400 and -1e-400 seems good... and then integral and decimal with no scientific (1, -1, 1.1, -1.1).

(And a PR is generally a better vessel for comments than individual commit hash links)

[vicrdguez]

@bartonjs thanks for the corrections, I will add it and create the test cases.
Im sorry for the hash link, is my first contribution.
Thanks for the help!!

[vicrdguez]

Im having troubles with the projects references since VS can't resolve any. Anywhere I can search about this problem? All the information I found doesn't help.
Also a lot of features throw error:
The feature *feature name* is currently in preview and *unsuported*. To use preview features, use 'preview' language version.

I have the preview sdk and runtime so I can't figure what is wrong

[bartonjs]

Are you getting those errors as red squiggles, or compiling is actually failing? (IIRC we have a problem that's being worked on where the VS experience in corefx is broken-looking, but the compile succeeds)

[vicrdguez]

@bartonjs I have the red squiggles when I load the project, anyways when compiling it fails. First its like the project doesn't find the target framework. I added netcoreapp3.0 by hand in the csproj but then, the references errors appear

[bartonjs]

Did you run build.cmd (or build.sh) from the root before loading VS?

[vicrdguez]

Im doing a fresh instalation of cmake, sdk and runtime. I will then run build.cmd. Let's see if I can make this work.
Thanks!

[vicrdguez]

After some testes and re installing everithing, thats what I get when trying to run tests:

[7/9/2019 09:31:33  Error] Testhost process exited with error: It was not possible to find any compatible framework version
The specified framework 'Microsoft.NETCore.App', version '3.0.0' was not found.
  - The following frameworks were found:
      2.1.2 at [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
      2.1.5 at [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
      2.1.11 at [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
      2.1.12 at [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
      2.2.5 at [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
      2.2.6 at [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
      3.0.0-preview6-27804-01 at [C:\Program Files\dotnet\shared\Microsoft.NETCore.App]
You can resolve the problem by installing the specified framework and/or SDK.
The .NET Core frameworks can be found at:
  - https://aka.ms/dotnet-download

I have preview six but is like there is another newer installed(?)
When I ran build.cmd I saw this:
dotnet-install: Downloading link: https://dotnetcli.azureedge.net/dotnet/Sdk/3.0.100-preview7-012630/dotnet-sdk-3.0.100-preview7-012630-win-x64.zip

As you can see says preview7

Right after VS2019 notice me about a new update. Maybe the preview7 is being released but not available for downlad yet?