fix(eslint-plugin): [consistent-indexed-object-style] do not autofix if interface has extends

[armano2]

Disable reporting when interface has extends

fixes #3007

[typescript-eslint]

Thanks for the PR, @armano2!

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[codecov]

Codecov Report

Merging #3009 (200b97d) into master (5e2a993) will increase coverage by 0.00%.
The diff coverage is 100.00%.

@@           Coverage Diff           @@
##           master    #3009   +/-   ##
=======================================
  Coverage   92.87%   92.87%           
=======================================
  Files         314      314           
  Lines       10670    10673    +3     
  Branches     3026     3028    +2     
=======================================
+ Hits         9910     9913    +3     
  Misses        344      344           
  Partials      416      416           

Flag	Coverage Δ
unittest	92.87% <100.00%> (+<0.01%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...lugin/src/rules/consistent-indexed-object-style.ts	90.00% <100.00%> (+0.63%)	⬆️

[bradzacher]

this doesn't just prevent a fix - this also prevents reporting.
I don't think that's correct.

We can still report and leave it to the user to fix.

Or we can just fix it to an intersection type:

interface B extends A { [i: string]: number }
// fix to
type B = A & Record<string, number>;

[armano2]

we can't really fix this

interface B extends A { [i: string]: number }
// fix to
type B = A & Record<string, number>;

this is not same code, in many cases it may behave differently

---

type TypeA = Record<string, null>

interface TypeB extends TypeA {
	[i: string]: number
}

type TypeC = TypeA & Record<string, number>;

TypeB - is going to report error Type 'number' is not assignable to type 'null'.(2430)
TypeC - there is no error reported

https://www.typescriptlang.org/play?#code/C4TwDgpgBAKuEEEoF4oCUIGMD2AnAJgDwDOwuAlgHYDmANFJQK4A2zAfALABQ3VwEuAGYBDTNDiQAQlAgAPfpXzFY8JAG9uASADa5AFxRSFGgF0DTALYAjAdwC+3bqEgrIAYRSvEUAGToseERGVHQMjNYCbADc3EA

---

i updated PR title

[bradzacher]

I think we should still report on this and have the user figure out the best way to action.
It's not going to be clear to most people why this case isn't covered, and it'll look like a bug in the rule.

We can document it in the rule docs, but most people don't read those too deeply...

[armano2]

there is one more case that can cause issues, when interface has more than one extends

interface TypeB extends TypeA, TypeC {
	[i: string]: number
}

[armano2]

I think we should still report on this and have the user figure out the best way to action.

ok, just changed it

[bradzacher]

thanks!