List of syntactic definition file errors we could detect

[RyanCavanaugh]

Signatures that differ only by a single parameter type

declare function fn2(x: number): void;
// Error, write one signature taking string|number
declare function fn2(x: string): void;

Signatures that differ only by omitting by a parameter

declare function fn6(): void;
// Error, write one signature with one optional parameter
declare function fn6(s: string): void;

Use of the non-primitive names anywhere

(except in a interface Number { declaration)

declare var var1: Number; // Error, use 'number'

Optional parameters in callback positions:

declare function fn5(callback: (key: string, value?: number) => void): void;

[dead-claudia]

Just an opinion, but this sounds more like a linter error than a syntax error. Not saying it's a bad idea to warn, but I would disagree about it being something that should be completely rejected.

[mhegazy]

@isiahmeadows the intention here is to implement these as tslint rules and suggest them for definition authors, and may be run them on definitelytyped CI.

[dead-claudia]

@mhegazy Oh. Okay. I get what you mean.

[RyanCavanaugh]

Non-consecutive function overloads in the same block

interface Foo {
  x(): void;
  y(): void;
  x(s: string): number; // <-- error, all 'x' signatures should be adjacent
}

[mhegazy]

@rakatyal can we mark this as completed?