Feature Request: Add equivalent of ESLint no-multi-spaces rule

[nabeel-quintet]

Feature Request: Add equivalent of ESLint no-multi-spaces rule

References

• https://eslint.org/docs/latest/rules/no-multi-spaces
• https://eslint.style/rules/no-multi-spaces

Description

While migrating from ESLint to Biome, I noticed there is no equivalent rule for ESLint’s no-multi-spaces.

In ESLint, this rule:

• Disallows multiple consecutive spaces between tokens (excluding indentation).
• Can be configured to allow alignment exceptions.
• Reports lint errors independently from formatting.
• Can be enforced strictly at the CI level.

Currently, Biome does not appear to provide a dedicated lint rule that enforces this behavior.

---

Expected Behavior

Biome should provide a lint rule equivalent to ESLint’s no-multi-spaces with the following characteristics:

• Report consecutive spaces between tokens.
• Ignore indentation.
• Optionally support alignment exceptions.
• Be enforceable at lint level (not only through formatting).
• Allow CI to fail specifically due to multi-space violations.

Example Diagnostic

const a  = 1;
//       ^ Unexpected multiple spaces.

Example

const a  = 1;
const b   = 2;
const obj = { key:  "value" };

ESLint (no-multi-spaces)

Reports lint errors for the extra spaces between tokens.

Biome

No lint error is reported.
Spacing is only corrected when running the formatter.

[dyc3]

We intentionally haven't implemented this rule because the behavior is completely covered by the formatter. In general, we don't implement lint rules that just do code formatting, because we have the formatter to do that.