create-graphql-type

name	create-graphql-type
description	From a raw JSON payload, generate TypeScript `type` declarations (no interfaces) matching the project conventions.

Create GraphQL type

Turn a raw JSON object into typed TypeScript type declarations for libs/shared/src/graphQL/.

Inputs

The user either:

• Pastes the JSON inline in the /create-graphql-type message, or
• Passes no JSON, in which case ask once: "Paste the JSON payload you want to type."

Always ask (separate question, do not batch): "What should the top-level exported type be named? (PascalCase, e.g. QueryNpvArtistData)"

Type-generation rules

Apply these rules recursively to every node in the JSON tree.

1. One type per distinct object shape

For every object value, create a named type. Do not inline object shapes beyond one level of nesting. Name sub-types by concatenating the parent name + the key in PascalCase (e.g. Artist → ArtistProfile for the profile key).

2. Only type, never interface

Emit type Foo = { … }. Never interface.

3. Export rules

• Export only the top-level type (the name the user provided).
• All helper types in the same file are unexported (type Foo = … without export).

4. Array values

Use TypeName[] (never Array<TypeName>).

5. Primitive inference

JSON value	TypeScript
"some string"	string
42 / 3.14	number
true / false	boolean
null	null (add | null to the field)
"spotify:track:…" / "spotify:artist:…" etc.	`spotify:track:${string}` (template literal)

6. __typename discriminants

If a field is named __typename and its value is a non-empty string, type it as the string literal: __typename: 'Artist', not __typename: string.

7. Unknown / empty arrays

If an array in the JSON is empty ([]), type its element as unknown.

8. Unknown / empty objects

If an object value is {}, type it as unknown.

Output format

Emit a single fenced TypeScript block with the complete file content.

Example

Input JSON:

{
    "queryNpvArtist": {
        "artist": {
            "__typename": "Artist",
            "uri": "spotify:artist:abc",
            "profile": { "name": "Daft Punk" },
            "visuals": {
                "avatarImage": {
                    "sources": [
                        { "url": "https://…", "width": 640, "height": 640 }
                    ]
                }
            }
        }
    }
}

Top-level name: QueryNpvArtistData

Expected output:

export type QueryNpvArtistData = {
    queryNpvArtist: QueryNpvArtist;
};

type QueryNpvArtist = {
    artist: Artist;
};

type Artist = {
    __typename: 'Artist';
    uri: `spotify:artist:${string}`;
    profile: ArtistProfile;
    visuals: ArtistVisuals;
};

type ArtistProfile = {
    name: string;
};

type ArtistVisuals = {
    avatarImage: ArtistVisualsAvatarImage | null;
};

type ArtistVisualsAvatarImage = {
    sources: ArtistVisualsAvatarImageSource[];
};

type ArtistVisualsAvatarImageSource = {
    url: string;
    width: number;
    height: number;
};

Conventions reminder

• 4-space indent, single quotes, trailing commas, semicolons (see root .prettierrc).
• consistent-type-imports: use import type { … } for type-only imports.
• Do not use interface.