Empty output for TypeScript → JSONSchema conversion

[danvk]

I can use the quicktype web interface to convert a TypeScript interface definition to more verbose JSONSchema:

But I'm unable to do the same from the command line. I just get an empty schema.json output:

$ cat name.ts
interface Name {
    first: string;
    last: string;
}                                                                                                                                                                                                                                                $ quicktype --src-lang typescript --src name.ts --lang schema --out schema.json
$ cat schema.json
{
    "$schema": "http://json-schema.org/draft-06/schema#",
    "definitions": {}
}
$ quicktype --version
quicktype version 15.0.62
Visit quicktype.io for more info.

Am I missing something?

[dvdsgl]

Using quicktype name.ts -o schema.json -l schema works for me!

❯ cat name.ts
interface Name {
    first: string;
    last: string;
}
❯ quicktype name.ts -o schema.json -l schema
❯ cat schema.json 
{
    "$schema": "http://json-schema.org/draft-06/schema#",
    "definitions": {
        "Name": {
            "title": "Name",
            "type": "object",
            "properties": {
                "first": {
                    "type": "string",
                    "title": "first"
                },
                "last": {
                    "type": "string",
                    "title": "last"
                }
            },
            "required": [
                "first",
                "last"
            ]
        }
    }
}

[danvk]

I couldn't get it to work yesterday, now today I can't get it to fail! There was a version bump, from 15.0.62 to 15.0.63. Maybe that explains it. I'll let you know if I can reproduce, but thanks for checking!

[danvk]

I was able to reproduce this with the most-recent version of quicktype, so I'm reopening.

$ cat name.ts
interface Name {
    first: string;
    last: string;
}
$ quicktype name.ts -o schema.json -l schema
$ cat schema.json
{
    "$schema": "http://json-schema.org/draft-06/schema#",
    "definitions": {}
}

$ quicktype --version
quicktype version 15.0.64
Visit quicktype.io for more info.

I installed quicktype via yarn global add quicktype.

[dvdsgl]

What node version? I get a different result (expected behavior) with node v8.11.2

[danvk]

$ node --version
v9.11.1

[schani]

@danvk Would you mind checking whether it works with node 8?

[danvk]

It does not:

$ node --version
v8.11.2
$ cat name.ts
interface Name {
    first: string;
    last: string;
}

$ quicktype name.ts -o schema.json -l schema
$ cat schema.json
{
    "$schema": "http://json-schema.org/draft-06/schema#",
    "definitions": {}
}

In case it is relevant, I'm on Mac OS 10.13.3 (17D47).

[schani]

This is highly odd. Did you install the NPM package or compile locally?

[danvk]

I ran `yarn global add quicktype`

…

On Fri, Jul 20, 2018 at 11:10 AM Mark Probst ***@***.***> wrote: This is highly odd. Did you install the NPM package or compile locally? — You are receiving this because you were mentioned. Reply to this email directly, view it on GitHub <#966 (comment)>, or mute the thread <https://github.com/notifications/unsubscribe-auth/AAF__ZdIuigA_Jb2-A1qJ5nBzhDqaAmTks5uIfLvgaJpZM4VRtRi> .

[schani]

I tried installing via yarn, too, and that also works. My best guess is that for some reason some package isn't the right version, most likely typescript-json-schema, though I wouldn't know how to check for that. On the other hand, the current typescript-json-schema also works. Could you try installing that package and seeing if it works, actually? You run it as

typescript-json-schema name.ts "*"

[danvk]

Aha!

I installed typescript-json-schema globally and ran it. Here's what happened:

$ cd ~/.config/yarn/global
$ yarn list typescript-json-schema
yarn list v1.5.1
warning Filtering by arguments is deprecated. Please use the pattern option instead.
├─ quicktype@15.0.65
│  └─ typescript-json-schema@0.22.0
└─ typescript-json-schema@0.27.0
✨  Done in 0.47s.
$ cat name.ts
interface Name {
    first: string;
    last: string;
}
$ typescript-json-schema name.ts "*"
/Users/danvk/.config/yarn/global/node_modules/@types/graphql/subscription/subscribe.d.ts (17,12): Cannot find name 'AsyncIterator'.
/Users/danvk/.config/yarn/global/node_modules/@types/graphql/subscription/subscribe.d.ts (29,12): Cannot find name 'AsyncIterable'.

I have those @types installed because of apollo:

$ yarn why @types/graphql
yarn why v1.5.1
[1/4] 🤔  Why do we have the module "@types/graphql"...?
[2/4] 🚚  Initialising dependency graph...
[3/4] 🔍  Finding dependency...
[4/4] 🚡  Calculating file sizes...
=> Found "@types/graphql@0.12.6"
info Reasons this module exists
   - "apollo#apollo-link" depends on it
   - Hoisted from "apollo#apollo-link#@types#graphql"
info Disk size without dependencies: "372kB"
info Disk size with unique dependencies: "372kB"
info Disk size with transitive dependencies: "372kB"
info Number of shared dependencies: 0
✨  Done in 0.47s.

If I remove that file, both typescript-json-schema and quicktype start behaving as expected.

So as I read it, this is:

1. a bug with typescript-json-schema, rather than quicktype and
2. caused by some kind of mismatch between the TypeScript libs assumed by @types/graphql and those assumed by typescript-json-schema.

[schani]

It isn't necessarily an error with typescript-json-schema, just some mismatch. We actually use a fork of that package because we needed a few things fixed and upstream wasn't quite responsive.

I'm not sure what a good solution would be for you here. It can't be that you're only allowed one version of each package?