Deno: Deno.open mode

[MarkTiedemann]

I believe open should accept the mode as a number rather than a string to allow multiple modes to be combined (via bitwise-or). For example, I want to express that I want to open a file to be written, and to be created first, if it doesn't exist, as in O_WRONLY | O_CREAT (where O_WRONLY = 0x1 and O_CREAT = 0x40).

Example:

async function main() {
  let file = Deno.open("google.html", Deno.OPEN_WRITE | Deno.OPEN_CREATE);
  let conn = await Deno.dial("tcp", "google.com:80");
  await conn.write(new TextEncoder().encode("GET /\n"));
  return Deno.copy(await file, conn);
}

main();

Edit 1: This would be in line with Go's open flags: https://golang.org/pkg/os/#pkg-constants

Edit 2: If you use "w", currently it will automatically create a new file if it doesn't exist. The point is to make this explicit in the flags. For example, I would expect "w" to fail if the file doesn't exist (since the create flag is not explicit).

[kevinkassimo]

The Go open flags are basically the *nix commons.
Another option is to design an OpenOptions similar to the one used by Deno.writeFile: https://deno.land/typedoc/interfaces/deno.writefileoptions.html

[MarkTiedemann]

I think there's one question regarding the names: Do we use the classic Unix names (for example, O_WRONLY, O_CREAT) or simplified names (for example, write [write_only?], create)?

And the second question: How do we allow multiple flags to be passed to the API? Options object, array spread, or bitmask?

open(file, { write: true, create: true })
open(file, O_WRITE, O_CREATE)
open(file, O_WRITE | O_CREATE)

I think that simple names in combination with an options object are the most idiomatic for JavaScript (though I do also see value in sticking with the actual Unix names and using bitmasks).

[ry]

open(file, { write: true, create: true })

Seams most reasonable to me

I can’t find the link but there was a comment from one of the Go people describing regrets in the API and the only one they could come up with was that they hadn’t renamed these flags...

[bartlomieju]

3119 landed, so I consider this issue resolved