noSelfAssign (since v12.0.0)

Disallow assignments where both sides are exactly the same.

Self assignments have no effect, so probably those are an error due to incomplete refactoring.

Source: https://eslint.org/docs/latest/rules/no-self-assign

Examples

Invalid

jsx

a = a;

<pre class="language-text"><code class="language-text">nursery/noSelfAssign.js:1:5 <a href="https://docs.rome.tools/lint/rules/noSelfAssign">lint/nursery/noSelfAssign</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ✖ a is assigned to itself. > 1 │ a = a; │ ^ 2 │ ℹ This is where is assigned. > 1 │ a = a; │ ^ 2 │ </code></pre>

jsx

[a] = [a];

<pre class="language-text"><code class="language-text">nursery/noSelfAssign.js:1:8 <a href="https://docs.rome.tools/lint/rules/noSelfAssign">lint/nursery/noSelfAssign</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ✖ a is assigned to itself. > 1 │ [a] = [a]; │ ^ 2 │ ℹ This is where is assigned. > 1 │ [a] = [a]; │ ^ 2 │ </code></pre>

jsx

({a: b} = {a: b});

<pre class="language-text"><code class="language-text">nursery/noSelfAssign.js:1:15 <a href="https://docs.rome.tools/lint/rules/noSelfAssign">lint/nursery/noSelfAssign</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ✖ b is assigned to itself. > 1 │ ({a: b} = {a: b}); │ ^ 2 │ ℹ This is where is assigned. > 1 │ ({a: b} = {a: b}); │ ^ 2 │ </code></pre>

jsx

a.b = a.b;

<pre class="language-text"><code class="language-text">nursery/noSelfAssign.js:1:9 <a href="https://docs.rome.tools/lint/rules/noSelfAssign">lint/nursery/noSelfAssign</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ✖ b is assigned to itself. > 1 │ a.b = a.b; │ ^ 2 │ ℹ This is where is assigned. > 1 │ a.b = a.b; │ ^ 2 │ </code></pre>

jsx

a[b] = a[b];

<pre class="language-text"><code class="language-text">nursery/noSelfAssign.js:1:10 <a href="https://docs.rome.tools/lint/rules/noSelfAssign">lint/nursery/noSelfAssign</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ✖ b is assigned to itself. > 1 │ a[b] = a[b]; │ ^ 2 │ ℹ This is where is assigned. > 1 │ a[b] = a[b]; │ ^ 2 │ </code></pre>

jsx

a[b].foo = a[b].foo;

<pre class="language-text"><code class="language-text">nursery/noSelfAssign.js:1:17 <a href="https://docs.rome.tools/lint/rules/noSelfAssign">lint/nursery/noSelfAssign</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ✖ foo is assigned to itself. > 1 │ a[b].foo = a[b].foo; │ ^^^ 2 │ ℹ This is where is assigned. > 1 │ a[b].foo = a[b].foo; │ ^^^ 2 │ </code></pre>

jsx

a['b'].foo = a['b'].foo;

<pre class="language-text"><code class="language-text">nursery/noSelfAssign.js:1:21 <a href="https://docs.rome.tools/lint/rules/noSelfAssign">lint/nursery/noSelfAssign</a> ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━ ✖ foo is assigned to itself. > 1 │ a['b'].foo = a['b'].foo; │ ^^^ 2 │ ℹ This is where is assigned. > 1 │ a['b'].foo = a['b'].foo; │ ^^^ 2 │ </code></pre>

Valid

jsx

a &= a;
var a = a;
let a = a;
const a = a;
[a, b] = [b, a];

Lint Rule noSelfAssign

noSelfAssign (since v12.0.0)

Examples

Invalid

Valid

Related links