Description
- [x ] I have tried restarting my IDE and the issue persists.
- [ x] I have updated to the latest version of the packages.
- [x ] I have read the FAQ and my problem is not listed.
Repro
The following code wrongly reports Unnecessary conditional, value is always falsy. It's a simplification of several cases where I have if-statements with negations for a function's boolean return value.
const isEven = (val: number) => val % 2 === 0;
if (!isEven(1)) {
console.log('Odd value');
}
Rule definition in .eslintrc.yml:
rules:
# ...
"@typescript-eslint/no-unnecessary-condition": errortsconfig.json:
{
"compilerOptions": {
"target": "ES2019",
"module": "commonjs",
"alwaysStrict": true,
"esModuleInterop": true,
"experimentalDecorators": true,
"forceConsistentCasingInFileNames": true,
"importHelpers": true,
"inlineSourceMap": true,
"inlineSources": true,
"noErrorTruncation": true,
"noFallthroughCasesInSwitch": true,
"noImplicitAny": true,
"noImplicitReturns": true,
"noUnusedLocals": true,
"noUnusedParameters": true,
"preserveWatchOutput": true,
"removeComments": false,
"skipLibCheck": true,
"strict": true,
"strictFunctionTypes": true,
"strictNullChecks": true,
"strictPropertyInitialization": true,
"lib": [
"ES5",
"ES2015",
"ES2016",
"ES2017",
"ES2018",
"ES2019",
"ES2020",
"dom"
],
"outDir": "./dist"
},
"exclude": ["config", "dist", "test", "node_modules", "scripts", "temp"]
}Expected Result
No message
Actual Result
Message Unnecessary conditional, value is always falsy.
Versions
| package | version |
|---|---|
@typescript-eslint/eslint-plugin |
3.9.2-alpha.10 |
@typescript-eslint/parser |
3.9.2-alpha.10 |
TypeScript |
4.0.2 |
ESLint |
7.7.0 |
node |
14.8.0 |