noAssignInExpressions
Diagnostic Category: lint/suspicious/noAssignInExpressions
Since: v1.0.0
Sources:
- Inspired from:
no-cond-assign
Description
Section titled DescriptionDisallow assignments in expressions.
In expressions, it is common to mistype a comparison operator (such as ==
) as an assignment operator (such as =
).
Moreover, the use of assignments in expressions is confusing.
Indeed, expressions are often considered as side-effect free.
Examples
Section titled ExamplesInvalid
Section titled Invalidlet a, b;a = (b = 1) + 1;
code-block.ts:2:6 lint/suspicious/noAssignInExpressions ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
✖ The assignment should not be in an expression.
1 │ let a, b;
> 2 │ a = (b = 1) + 1;
│ ^^^^^
3 │
ℹ The use of assignments in expressions is confusing.
Expressions are often considered as side-effect free.
let a;if (a = 1) {}
code-block.ts:2:5 lint/suspicious/noAssignInExpressions ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
✖ The assignment should not be in an expression.
1 │ let a;
> 2 │ if (a = 1) {
│ ^^^^^
3 │ }
4 │
ℹ The use of assignments in expressions is confusing.
Expressions are often considered as side-effect free.
function f(a) { return a = 1;}
code-block.ts:2:12 lint/suspicious/noAssignInExpressions ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━
✖ The assignment should not be in an expression.
1 │ function f(a) {
> 2 │ return a = 1;
│ ^^^^^
3 │ }
4 │
ℹ The use of assignments in expressions is confusing.
Expressions are often considered as side-effect free.
Valid
Section titled Validlet a;a = 1;
How to configure
Section titled How to configure{ "linter": { "rules": { "suspicious": { "noAssignInExpressions": "error" } } }}