[FR] Self-provided `--user-data-dir`

[lowlighter]

Currently you always need the temp dir in --allow-write because the following is not gated so you'll always hit a permission request: https://github.com/lino-levan/astral/blob/7e91588e342561a2e5a3b515e7b3cedf6683d02b/src/browser.ts#L253

And the arg --user-data-dir is always set by astral: https://github.com/lino-levan/astral/blob/7e91588e342561a2e5a3b515e7b3cedf6683d02b/src/browser.ts#L261

But it'd be nice if the above lines are ignored if user specify the arg theymselves in args: https://github.com/lino-levan/astral/blob/7e91588e342561a2e5a3b515e7b3cedf6683d02b/src/browser.ts#L232

Basically doing something like:

if (!args.find(arg => arg.startsWith("--user-data-dir=")) {
  const tempDir = Deno.makeTempDirSync(); 
  args.push(`--user-data-dir=${tempDir}`) 
}

I know the workaround from #56, but setting TMPDIR is not always convenient because:

• it sets the value globally for all the program and its dependencies, not only astral
• it conflicts with users wanting to manually set this parameter
  • additionally it prevents the pattern where a single directory is used to store all of app's cache/data, etc.
  • users cannot handle the lifecycle of their app completly as there's no way to retrieve the generated user-data-dir so it cannot be cleaned when exiting (although leaving stuff in temp dir is usually not a big deal, but it's still a small inconvenience)
• not sure as I haven't personally tested yet, but firefox may not have this arg so it'd mean that an extra permission is requested although it may be unneeded

[lino-levan]

Basically doing something like:

if (!args.find(arg => arg.startsWith("--user-data-dir=")) { const tempDir = Deno.makeTempDirSync(); args.push(--user-data-dir=${tempDir}) }

I would support this. If you want to submit a PR this makes sense to me.

I haven't personally tested yet, but firefox may not have this arg

Firefox compatibility is currently really broken. Hoping that #84 fixes it in the medium-long term.