strict-comparison false positive (TSLint 5.18.0)

[vladimir-djokic]

Bug Report

• TSLint version: 5.18.0
• TypeScript version: 3.5.2
• Running TSLint via: VSCode

TypeScript code being linted

const foo: string | null = null;

if (foo !== null) { // <-- Cannot use '!==' comparator for type 'null'. (strict-comparisons)tslint(1)
    // ...
}

with tslint.json configuration:

{
    "extends": "tslint:all",
    "rules": {
        "linebreak-style": false,
        "no-null-keyword": false,
        "strict-type-predicates": false
    }
}

Actual behavior

strict-comparison error.

Expected behavior

No error.

[ulrichb]

Same here. The exclusion for "if one of the operands is null or undefined" doesn't seem to work.

[ulrichb]

... and in addition to the sample above it should also work for non-primitives on the other side, right?

Example:

const someObj : {} | undefined = {};
if (someObj === undefined) { /* ... */ }