[BUG]: cant convert empty object to dts

[jonnytest1]

Issue Type

an empty object doesnt get converted to dts

Context (Environment, Version, Language)

Input Format: json schema
Output Language: typescript

CLI, npm, or app.quicktype.io:
Version: https://app.quicktype.io/

Description

Input Data

{
"id": "http://json-schema.org/geo",
"$schema": "http://json-schema.org/draft-06/schema#",
"type": "object",
"properties":{}
}

Expected Behaviour / Output

export type Name = {} // or whatever the typescsipt equivalent of an empty object is ^^

Current Behaviour / Output

breaks

workaround:

wrap in subobject:

if(schema.type=="object" && !schema.properties){
 jsonSchema = {
      type: "object",
      properties: {
        wrapper: jsonSchema
      },
      required: ["wrapper"],
      additionalProperties: false
    }
}

...

 lines[0] = ""
    lines[1] = lines[1].replace(/wrapper: ([^;]*);/, `export type ${mainTypeName} = $1;`).trim()
    lines[2] = ""
    return `
        ${lines.join("\n")}
    `.trim()

[schani]

Triage sweep note (assisted by Claude): confirmed reproducible on current master (v23.3.0, 68ecb284).

Root cause: An empty-object schema ({"type":"object","properties":{}}) is inferred as a MapType ({ [key: string]: any }). TypeScriptFlowBaseRenderer.emitTypes (packages/quicktype-core/src/language/TypeScriptFlow/TypeScriptFlowBaseRenderer.ts:174) only emits a top-level export type alias for primitive top-levels plus named classes/enums/unions — a bare map type at the top level falls through and nothing gets emitted. With --just-types the output is completely empty (not even an error); without it you only get the Convert boilerplate with an inline map type. Go handles the same input correctly (type EmptySchema map[string]interface{}), confirming this is TS/Flow (and likely C#, similar gap) specific rather than intended behavior.

Assessment: severity medium — no crash, but silently empty/wrong output for a legitimate (if unusual) schema is a real footgun, especially with --just-types where there's no clue anything went wrong. Fix difficulty: easy — extend the top-level-emission loop in TypeScriptFlowBaseRenderer.emitTypes to also emit export type X = ...; for non-primitive, non-named top-level types (maps/arrays), mirroring the existing primitive branch.

Reproduction:

node dist/index.js --lang typescript --src-lang schema --just-types empty.schema.json

{
  "id": "http://json-schema.org/geo",
  "$schema": "http://json-schema.org/draft-06/schema#",
  "type": "object",
  "properties":{}
}

Output: empty (nothing printed).