[no-unnecessary-type-assertion] false positive when asserting via non-null assertion operator #529
Description
Repro
https://github.com/vkrol/typescript-eslint-no-unnecessary-type-assertion-undefined
module.exports = {
parser: "@typescript-eslint/parser",
parserOptions: {
project: "tsconfig.json",
},
plugins: ["@typescript-eslint"],
rules: {
"@typescript-eslint/no-unnecessary-type-assertion": "error",
}
};declare function foo(str?: string): void;
declare const str: string | null;
foo(str!);Expected Result
No errors.
Actual Result
Error:
D:\Projects\typescript-eslint-no-unnecessary-type-assertion-undefined\index.ts
4:5 error This assertion is unnecessary since the receiver accepts the original type of the expression @typescript-eslint/no-unnecessary-type-assertion
✖ 1 problem (1 error, 0 warnings)
1 error and 0 warnings potentially fixable with the `--fix` option.
Additional Info
The change that introduced this regression: #478.
Versions
| package | version |
|---|---|
@typescript-eslint/eslint-plugin |
1.9.0 |
@typescript-eslint/parser |
1.9.0 |
TypeScript |
3.4.5 |
ESLint |
5.16.0 |
node |
10.15.3 |
npm |
6.4.1 |