typescript/no-non-null-asserted-optional-chain Correctness
What it does
Disallow non-null assertions after an optional chain expression.
Why is this bad?
?. optional chain expressions provide undefined if an object is null or undefined. Using a ! non-null assertion to assert the result of an ?. optional chain expression is non-nullable is likely wrong.
Most of the time, either the object was not nullable and did not need the ?. for its property lookup, or the ! is incorrect and introducing a type safety hole.
Example
ts
foo?.bar!;
foo?.bar()!;How to use
To enable this rule in the CLI or using the config file, you can use:
bash
oxlint --deny typescript/no-non-null-asserted-optional-chainjson
{
"rules": {
"typescript/no-non-null-asserted-optional-chain": "error"
}
}