[BUG]: quicktype-core silently ignores unknown rendererOptions keys

[schani]

Issue Type

quicktype-core API (developer experience).

Context (Environment, Version, Language)

Input Format: JSON
Output Language: any

CLI, npm, or app.quicktype.io: npm (quicktype-core)
Version: 25.0.0-pre1 (also reproduces on 24.0.2)

Description

Passing an unrecognized key in rendererOptions is silently ignored — no error, no warning. A typo (or an option name that exists for a different language) produces default output with no signal that the option had no effect:

const { quicktype, InputData, jsonInputForTargetLanguage } = require("quicktype-core");

const jsonInput = jsonInputForTargetLanguage("typescript");
await jsonInput.addSource({ name: "X", samples: ['{"a": 1}'] });
const inputData = new InputData();
inputData.addInput(jsonInput);

// "totally-bogus-option" is accepted without complaint
const result = await quicktype({
    inputData,
    lang: "typescript",
    rendererOptions: { "totally-bogus-option": "yes" },
});

The CLI does the right thing here (Error: Option parsing failed: Unknown option: --just-typs.), so the core API is strictly less safe than the CLI for the same mistake. This bit me for real while testing: I passed C#'s just-types spelling to a language that names it differently and got silently un-customized output.

Expected Behavior

quicktype() should throw (or at minimum warn via debugPrintTimes-style logging) when a rendererOptions key doesn't match any option of the target language. Since RendererOptions is already typed per-language in newer versions, a runtime check would also catch untyped/dynamic callers (plain JS, options loaded from config files).

🤖 Filed with Claude Code