no-extra-non-null-assertion
NOTE: this rule is part of the
recommended rule set.Enable full set in
deno.json:{
"lint": {
"rules": {
"tags": ["recommended"]
}
}
}Enable full set using the Deno CLI:
deno lint --rules-tags=recommended
This rule can be explictly included to or excluded from the rules present in the current tag by adding it to the
include or exclude array in deno.json:{
"lint": {
"rules": {
"include": ["no-extra-non-null-assertion"],
"exclude": ["no-extra-non-null-assertion"]
}
}
}Disallows unnecessary non-null assertions.
Non-null assertions are specified with an ! saying to the compiler that you
know this value is not null. Specifying this operator more than once in a row,
or in combination with the optional chaining operator (?) is confusing and
unnecessary.
Invalid:
const foo: { str: string } | null = null;
const bar = foo!!.str;
function myFunc(bar: undefined | string) {
return bar!!;
}
function anotherFunc(bar?: { str: string }) {
return bar!?.str;
}
Valid:
const foo: { str: string } | null = null;
const bar = foo!.str;
function myFunc(bar: undefined | string) {
return bar!;
}
function anotherFunc(bar?: { str: string }) {
return bar?.str;
}