@putout/plugin-conditions
v5.0.0
Published
🐊Putout plugin adds support of conditions transformations
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@putout/plugin-conditions
🐊Putout adds support of conditions transformations.
Install
npm i @putout/plugin-conditions -D
Rules
- ✅ add-return;
- ✅ apply-comparison-order;
- ✅ apply-consistent-blocks;
- ✅ apply-if;
- ✅ convert-comparison-to-boolean;
- ✅ convert-equal-to-strict-equal;
- ✅ convert-arrow-to-condition;
- ✅ evaluate;
- ✅ merge-if-statements;
- ✅ remove-boolean;
- ✅ remove-constant;
- ✅ remove-same-values-condition;
- ✅ remove-useless-else;
- ✅ remove-zero;
- ✅ simplify;
Config
{
"rules": {
"conditions/apply-consistent-blocks": "on",
"conditions/apply-comparison-order": "on",
"conditions/apply-if": "on",
"conditions/add-return": "on",
"conditions/convert-comparison-to-boolean": "on",
"conditions/convert-equal-to-strict-equal": "on",
"conditions/convert-arrow-to-condition": "on",
"conditions/evaluate": "on",
"conditions/remove-boolean": "on",
"conditions/remove-constant": "on",
"conditions/remove-zero": "on",
"conditions/remove-useless-else": "on",
"conditions/remove-same-values-condition": "on",
"conditions/merge-if-statements": "on"
}
}
apply-consistent-blocks
A block statement is used to group zero or more statements. The block is delimited by a pair of braces ("curly braces") and contains a list of zero or more statements and declarations.
(c) MDN
Check out in 🐊Putout Editor:
❌ Example of incorrect code
if (a > 3) {
m();
}
if (a > 3)
b = 5;
else {
b = 6;
}
if (a > 3)
b = 5;
else {
b = 6;
fn();
}
✅ Example of correct code
if (a > 3)
m();
if (a > 3)
b = 5;
else
b = 6;
if (a > 3) {
b = 5;
} else {
b = 6;
fn();
}
apply-comparison-order
The result of evaluating an equality operator is always of type boolean based on whether the comparison is true.
(c) MDN
Checkout it 🐊Putout Editor.
❌ Example of incorrect code
3 === a;
3 < b;
✅ Example of correct code
a === 3;
b > 3;
Comparison
Linter | Rule | Fix
--------|-------|------------|
🐊 Putout| conditions/apply-comparison-order
| ✅
⏣ ESLint | yoda
| ½
apply-if
❌ Example of incorrect code
if (2 > 3)
;
alert();
✅ Example of correct code
if (2 > 3)
alert();
add-return
Checkout in 🐊Putout Editor.
❌ Example of incorrect code
if (a)
false;
✅ Example of correct code
if (a)
return false;
convert-arrow-to-condition
Checkout in 🐊Putout Editor.
❌ Example of incorrect code
if ((a) => b) {}
✅ Example of correct code
if (a <= b) {}
convert-comparison-to-boolean
Strict equality compares two values for equality. Neither value is implicitly converted to some other value before being compared. If the values have different types, the values are considered unequal.
(c) MDN
❌ Example of incorrect code
const t = 2 < 3;
✅ Example of correct code
const t = false;
convert-equal-to-strict-equal
The strict equality operator (
===
) checks whether its two operands are equal, returning aBoolean
result. Unlike the equality operator (==
), the strict equality operator always considers operands of different types to be different.(c) MDN
❌ Example of incorrect code
if (a == b) {}
✅ Example of correct code
if (a === b) {}
evaluate
The if statement executes a statement if a specified condition is truthy. If the condition is falsy, another statement can be executed.
(c) MDN
❌ Example of incorrect code
const a = [];
const c = a;
if (a)
console.log(a);
✅ Example of correct code
const a = [];
const c = a;
console.log(a);
remove-boolean
❌ Example of incorrect code
if (a === true)
alert();
✅ Example of correct code
if (a)
alert();
remove-constant
❌ Example of incorrect code
function hi(a) {
if (2 < 3) {
console.log('hello');
console.log('world');
}
}
✅ Example of correct code
function hi(b) {
console.log('hello');
console.log('world');
}
remove-zero
❌ Example of incorrect code
if (b === 0) {}
if (b !== 0) {}
✅ Example of correct code
if (!b) {}
if (b) {}
simplify
❌ Example of incorrect code
if (zone?.tooltipCallback)
zone.tooltipCallback(e);
if (a)
alert('hello');
else
alert('hello');
✅ Example of correct code
zone?.tooltipCallback(e);
alert('hello');
merge-if-statements
The
if
statement executes a statementif
a specified condition is truthy.(c) MDN
❌ Example of incorrect code
if (a > b)
if (b < c)
console.log('hello');
✅ Example of correct code
if (a > b && b < c)
console.log('hello');
remove-useless-else
You can skip the
else
block if yourif
block always executes areturn
statement, it makes code a lot easier to read.(c) no else return
Remove useless else
before:
return
;continue
;break
;
❌ Example of incorrect code
if (x)
return;
else
console.log();
✅ Example of correct code
if (x)
return;
console.log();
remove-same-values-condition
Checkout in 🐊Putout Editor.
❌ Example of incorrect code
for (const [i, el] of entries(elements)) {
if (el !== path)
continue;
if (!Number(i) && n) {
path.parentPath.node.elements[i] = null;
break;
}
if (el === path) {
remove(path);
break;
}
}
✅ Example of correct code
for (const [i, el] of entries(elements)) {
if (el !== path)
continue;
if (!Number(i) && n) {
path.parentPath.node.elements[i] = null;
break;
}
remove(path);
}
Comparison
Linter | Rule | Fix
--------|-------|------------|
🐊 Putout | conditions/remove-useless-else
| ✅
⏣ ESLint | no-else-return
| ✅
License
MIT