noImportAssign

JavaScript (and super languages)

Summary

• Rule available since: v1.0.0
• Diagnostic Category: lint/suspicious/noImportAssign
• This rule is recommended, which means is enabled by default.
• This rule doesn’t have a fix.
• The default severity of this rule is error.
• Sources:
  • Same as no-import-assign

How to configure

biome.json

{
  "linter": {
    "rules": {
      "suspicious": {
        "noImportAssign": "error"
      }
    }
  }
}

Description

Disallow assigning to imported bindings

Examples

Invalid

import x from "y";
x = 1;

code-block.js:2:1 lint/suspicious/noImportAssign ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ The imported variable x is read-only
  
    1 │ import x from “y”;
  > 2 │ x = 1;
      │ ^
    3 │ 
  
  ℹ The variable is imported here
  
  > 1 │ import x from “y”;
      │        ^
    2 │ x = 1;
    3 │ 
  
  ℹ Use a local variable instead of reassigning an import.
  

import y from "y";
[y] = 1;

code-block.js:2:2 lint/suspicious/noImportAssign ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ The imported variable y is read-only
  
    1 │ import y from “y”;
  > 2 │ [y] = 1;
      │  ^
    3 │ 
  
  ℹ The variable is imported here
  
  > 1 │ import y from “y”;
      │        ^
    2 │ [y] = 1;
    3 │ 
  
  ℹ Use a local variable instead of reassigning an import.
  

import z from "y";
({ z } = 1);

code-block.js:2:4 lint/suspicious/noImportAssign ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ The imported variable z is read-only
  
    1 │ import z from “y”;
  > 2 │ ({ z } = 1);
      │    ^
    3 │ 
  
  ℹ The variable is imported here
  
  > 1 │ import z from “y”;
      │        ^
    2 │ ({ z } = 1);
    3 │ 
  
  ℹ Use a local variable instead of reassigning an import.
  

import a from "y";
[...a] = 1;

code-block.js:2:5 lint/suspicious/noImportAssign ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ The imported variable a is read-only
  
    1 │ import a from “y”;
  > 2 │ […a] = 1;
      │     ^
    3 │ 
  
  ℹ The variable is imported here
  
  > 1 │ import a from “y”;
      │        ^
    2 │ […a] = 1;
    3 │ 
  
  ℹ Use a local variable instead of reassigning an import.
  

import b from "y";
({ ...b } = 1);

code-block.js:2:7 lint/suspicious/noImportAssign ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ The imported variable b is read-only
  
    1 │ import b from “y”;
  > 2 │ ({ …b } = 1);
      │       ^
    3 │ 
  
  ℹ The variable is imported here
  
  > 1 │ import b from “y”;
      │        ^
    2 │ ({ …b } = 1);
    3 │ 
  
  ℹ Use a local variable instead of reassigning an import.
  

import c from "y";
for (c in y) {};

code-block.js:2:6 lint/suspicious/noImportAssign ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ The imported variable c is read-only
  
    1 │ import c from “y”;
  > 2 │ for (c in y) {};
      │      ^
    3 │ 
  
  ℹ The variable is imported here
  
  > 1 │ import c from “y”;
      │        ^
    2 │ for (c in y) {};
    3 │ 
  
  ℹ Use a local variable instead of reassigning an import.
  

import d from "y";
d += 1;

code-block.js:2:1 lint/suspicious/noImportAssign ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ The imported variable d is read-only
  
    1 │ import d from “y”;
  > 2 │ d += 1;
      │ ^
    3 │ 
  
  ℹ The variable is imported here
  
  > 1 │ import d from “y”;
      │        ^
    2 │ d += 1;
    3 │ 
  
  ℹ Use a local variable instead of reassigning an import.
  

import * as e from "y";
e = 1;

code-block.js:2:1 lint/suspicious/noImportAssign ━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━━

  ✖ The imported variable e is read-only
  
    1 │ import * as e from “y”;
  > 2 │ e = 1;
      │ ^
    3 │ 
  
  ℹ The variable is imported here
  
  > 1 │ import * as e from “y”;
      │             ^
    2 │ e = 1;
    3 │ 
  
  ℹ Use a local variable instead of reassigning an import.
  

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