Tslint: semi: allow at start of line

Created on 19 May 2017 · 7Comments · Source: palantir/tslint

__TSLint version__: 5.2.0
__TypeScript version__: 2.4.0
__Running TSLint via__: WebStorm

TypeScript code being linted

function forFFxFy(f: R2_R, fx: R2_R, fy: R2_R) {
    ;(f as any).x = fx // tslint: unnecessary semicolon (semicolon)
    ;(f as any).y = fy // no error
    return f
}

with tslint.json configuration:

{
  "rules": {
    "semicolon": [true, "never"]
  }
}

Actual behavior

Error as above

Expected behavior

Strictly speaking, yes, the semicolon is unnecessary, but if code is added before the first line it will cause problems. Also, it's inconsistent :/

It would be nice if the "semi" rule had an option to allow this code style.

Formatting rule P3 Accepting PRs Bug 🌹 R.I.P. 🌹

Source

NaridaL

👍8

All 7 comments

zheeeng on 6 Sep 2017

Is there a way the solve this problem?

jackple on 12 Apr 2018

I get 'code is not alligned' and 'missing whitespace' with semicolon at the start of line.

ackvf on 19 Apr 2018

👍1

There is no proper solution. Prettier will also disagree on formatting, which is a hassle. As a workaround, you can use a pattern like

const anyF = f as any
anyF.x = fx

Ugly, but still slightly better than disabling and re-enabling align and whitespace rules whenever this comes up?

metrip on 4 May 2018

Here's the rationale from the side of Prettier as to why this should be allowed: https://prettier.io/docs/en/rationale.html#semicolons

Essentially, adding anything above these lines, without semicolons, would cause buggy code, so Prettier takes the defensive stance of being explicit that these are independent statements.

It would be nice if semicolon had an option to allow this type of defensive formatting.

blixt on 25 Oct 2018

👍1

We can take in an option to allow this. The option should include documentation similar to the Prettier docs for why such a seemingly ridiculous thing is necessary.

_aside: this is why I dislike ASI...!_