no-inferrable-types
Disallows easily inferrable types.
Variable initializations to JavaScript primitives (and null) are obvious in
their type. Specifying their type can add additional verbosity to the code. For
example, with const x: number = 5, specifying number is unnecessary as it is
obvious that 5 is a number.
Invalid:
const a: bigint = 10n;
const b: bigint = BigInt(10);
const c: boolean = true;
const d: boolean = !0;
const e: number = 10;
const f: number = Number("1");
const g: number = Infinity;
const h: number = NaN;
const i: null = null;
const j: RegExp = /a/;
const k: RegExp = RegExp("a");
const l: RegExp = new RegExp("a");
const m: string = "str";
const n: string = `str`;
const o: string = String(1);
const p: symbol = Symbol("a");
const q: undefined = undefined;
const r: undefined = void someValue;
class Foo {
prop: number = 5;
}
function fn(s: number = 5, t: boolean = true) {}
Valid:
const a = 10n;
const b = BigInt(10);
const c = true;
const d = !0;
const e = 10;
const f = Number("1");
const g = Infinity;
const h = NaN;
const i = null;
const j = /a/;
const k = RegExp("a");
const l = new RegExp("a");
const m = "str";
const n = `str`;
const o = String(1);
const p = Symbol("a");
const q = undefined;
const r = void someValue;
class Foo {
prop = 5;
}
function fn(s = 5, t = true) {}