`svelte-check --no-tsconfig` checks TS/JS

[fehnomenal]

Describe the bug

I want to only check svelte files and thus use svelte-check --no-tsconfig but it still loads the nearest tsconfig.json and checks TS/JS.

I added a log directly after parsing the options and this is what I got:

$ pnpm svelte-check --no-tsconfig
{
  _: [],
  tsconfig: false,
  workspace: undefined,
  output: 'human-verbose',
  watch: false,
  preserveWatchOutput: false,
  'no-tsconfig': false,
  ignore: undefined,
  'fail-on-warnings': false,
  'compiler-warnings': undefined,
  'diagnostic-sources': undefined,
  threshold: 'warning'
}

====================================
Loading svelte-check in workspace: /home/...
Getting Svelte diagnostics...

^CException: pnpm killed by signal interrupt
[tty 362], line 1: pnpm svelte-check --no-tsconfig

vs no flags:

$ pnpm svelte-check
{
  _: [],
  workspace: undefined,
  output: 'human-verbose',
  watch: false,
  preserveWatchOutput: false,
  tsconfig: undefined,
  'no-tsconfig': false,
  ignore: undefined,
  'fail-on-warnings': false,
  'compiler-warnings': undefined,
  'diagnostic-sources': undefined,
  threshold: 'warning'
}

====================================
Loading svelte-check in workspace: /home/...
Getting Svelte diagnostics...

^CException: pnpm killed by signal interrupt
[tty 363], line 1: pnpm svelte-check

As you can see no-tsconfig is always false and passing --no-tsconfig actually sets tsconfig to false instead of undefined.
And thus the early return in getTsconfig does not fire.

Reproduction

Well, call svelte-check --no-tsconfig in a project where there are type errors.

Expected behaviour

Do not display all the Typescript errors in .ts files.

System Info

• OS: NixOS (Linux)
• IDE: VSCodium

Which package is the issue about?

svelte-check

Additional Information, eg. Screenshots

No response