A command-line REPL for RESTful HTTP Services

My that's a lot of acronyms. REPL means "Read Evaluate Print Loop." You know how you can run "python" and then just type 2+2 and get answer? That's a type of REPL.

The ASP.NET Core team is building a REPL that lets you explore and interact with your RESTful services. Ideally your services will have Swagger/OpenAPI available that describes the service. Right now this Http-REPL is just being developed and they're aiming to release it as a .NET Core Global Tool in .NET Core 2.2.

You can install global tools like this:

dotnet tool install -g nyancat

Then you can run "nyancat." Get a list of installed tools like this:

C:\Users\scott> dotnet tool list -g
Package Id                 Version                   Commands
--------------------------------------------------------------------
altcover.global            3.5.560                   altcover
dotnet-depends             0.1.0                     dotnet-depends
dotnet-httprepl            2.2.0-preview3-35304      dotnet-httprepl
dotnet-outdated            2.0.0                     dotnet-outdated
dotnet-search              1.0.0                     dotnet-search
dotnet-serve               1.0.0                     dotnet-serve
git-status-cli             1.0.0                     git-status
github-issues-cli          1.0.0                     ghi
nukeeper                   0.7.2                     NuKeeper
nyancat                    1.0.0                     nyancat
project2015to2017.cli      1.8.1                     csproj-to-2017

For the HTTP-REPL, since it's not yet released you have to point the Tool Feed to a daily build location, so do this:

dotnet tool install -g --version 2.2.0-* --add-source https://dotnet.myget.org/F/dotnet-core/api/v3/index.json dotnet-httprepl

Then run it with "dotnet httprepl." I'd like another name? What do you think? RESTy? POSTr? API Test? API View?

Here's an example run where I start up a Web API.

C:\SwaggerApp> dotnet httprepl
(Disconnected)~ set base http://localhost:65369
Using swagger metadata from http://localhost:65369/swagger/v1/swagger.json
http://localhost:65369/~ dir
.        []
People   [get|post]
Values   [get|post]
http://localhost:65369/~ cd People
/People    [get|post]
http://localhost:65369/People~ dir
.      [get|post]
..     []
{id}   [get]
http://localhost:65369/People~ get
HTTP/1.1 200 OK
Content-Type: application/json; charset=utf-8
Date: Wed, 26 Sep 2018 20:25:37 GMT
Server: Kestrel
Transfer-Encoding: chunked
[
  {
    "id": 1,
    "name": "Scott Hunter"
  },
  {
    "id": 0,
    "name": "Scott Hanselman"
  },
  {
    "id": 2,
    "name": "Scott Guthrie"
  }
]

Take a moment and read that. It can be a little confusing. It's not HTTPie, it's not Curl, but it's also not PostMan. it's something that you run and stay running if you're a command line person and enjoy that space. It's as if you "cd (change directory)" and "mount" a disk into your Web API.

You can use all the HTTP Verbs, and when POSTing you can set a default text editor and it will launch the editor with the JSON written for you! Give it a try!

A few gotchas/known issues:

• You'll want to set a default Content-Type Header for your session. I think this should be default.
• set header Content-Type application/json
• If the HTTP REPL doesn't automatically detect your Swagger/OpenAPI endpoint, you'll need to set it manually:
• set base https://yourapi/api/v1/
• set swagger https://yourapi/swagger.json
• I haven't figure out how to get it to use VS Code as its default editor. Likely because "code.exe" isn't a thing. (It uses a batch .cmd file, which the HTTP REPL would need to special case). For now, use an editor that's an EXE and point the HTTP REPL like this:
• pref set editor.command.default 'c:\notepad2.exe'

I'm really enjoy this idea. I'm curious how you find it and how you'd see it being used. Sound off in the comments.

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