feat(lint): add nursery rule `useImportsFirst` by terror · Pull Request #9272 · biomejs/biome

terror · 2026-02-28T04:59:40Z

Summary

Resolves #9265

This diff Implements the useImportsFirst lint rule, which enforces that all import statements appear before any non-import statements in a module. This corresponds to the ESLint import/first rule (see #9265). The rule iterates over the module item list and flags any JsImport that appears after a non-import item.

Test Plan

Snapshot tests in crates/biome_js_analyze/tests/specs/nursery/useImportsFirst/:

invalid.js - imports after a const declaration (2 diagnostics)
invalid_mixed.js - imports interspersed with calls and exports (2 diagnostics)
valid.js - all imports grouped at the top (no diagnostics)
valid_with_export.js - single import before export and statement (no diagnostics)

Docs

Rule documentation is inline in the declare_lint_rule! macro and will be published automatically.

changeset-bot · 2026-02-28T04:59:45Z

🦋 Changeset detected

Latest commit: 70dec32

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 13 packages

Name	Type
@biomejs/biome	Patch
@biomejs/cli-win32-x64	Patch
@biomejs/cli-win32-arm64	Patch
@biomejs/cli-darwin-x64	Patch
@biomejs/cli-darwin-arm64	Patch
@biomejs/cli-linux-x64	Patch
@biomejs/cli-linux-arm64	Patch
@biomejs/cli-linux-x64-musl	Patch
@biomejs/cli-linux-arm64-musl	Patch
@biomejs/wasm-web	Patch
@biomejs/wasm-bundler	Patch
@biomejs/wasm-nodejs	Patch
@biomejs/backend-jsonrpc	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

coderabbitai · 2026-02-28T05:05:02Z

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between e5f5245 and 2a6ad5c.

⛔ Files ignored due to path filters (4)

crates/biome_js_analyze/tests/specs/nursery/useImportsFirst/invalid.js.snap is excluded by !**/*.snap and included by **
crates/biome_js_analyze/tests/specs/nursery/useImportsFirst/invalid_all_after.js.snap is excluded by !**/*.snap and included by **
crates/biome_js_analyze/tests/specs/nursery/useImportsFirst/invalid_mixed.js.snap is excluded by !**/*.snap and included by **
packages/@biomejs/biome/configuration_schema.json is excluded by !**/configuration_schema.json and included by **

📒 Files selected for processing (2)

crates/biome_js_analyze/src/lint/nursery/use_imports_first.rs
crates/biome_js_analyze/tests/specs/nursery/useImportsFirst/invalid_all_after.js

Walkthrough

Adds a new nursery lint rule UseImportsFirst (implements biome_analyze::Rule for Ast<JsModuleItemList) that flags import statements appearing after any non‑import module item. The rule performs a single‑pass over module items, returns offending TextRanges as signals, and produces diagnostics advising to move imports to the top. Includes UseImportsFirstOptions, rule registration metadata, a changeset, a public re‑export in biome_rule_options, and multiple test specs covering valid and invalid import orderings.

Suggested reviewers

ematipico
dyc3
unvalley

🚥 Pre-merge checks | ✅ 4

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and concisely describes the main change: adding a new nursery lint rule called useImportsFirst.
Description check	✅ Passed	The description is well-detailed, explaining the rule's purpose, referencing the resolved issue, and documenting the test plan and implementation approach.
Linked Issues check	✅ Passed	The PR fully addresses issue `#9265` by implementing the useImportsFirst rule that enforces imports appear before non-import statements, matching the ESLint import/first rule requirement.
Out of Scope Changes check	✅ Passed	All changes are directly related to implementing the useImportsFirst rule: rule implementation, test files, options struct, and changeset documentation.

_{✏️ Tip: You can configure your own custom pre-merge checks in the settings.}

✨ Finishing Touches

🧪 Generate unit tests (beta)

Create PR with unit tests
Post copyable unit tests in a comment

Thanks for using CodeRabbit! It's free for OSS, and your support helps us grow. If you like it, consider giving us a shout-out.

❤️ Share

_{Comment @coderabbitai help to get the list of available commands and usage tips.}

coderabbitai

Actionable comments posted: 1

🧹 Nitpick comments (1)

crates/biome_js_analyze/tests/specs/nursery/useImportsFirst/valid.js (1)
1-5: Optional: add a directive-focused valid fixture.

Given the rule docs explicitly allow directives, a tiny valid_with_directive.js (e.g. "use strict"; then imports) would lock that behaviour in and guard regressions.

Based on learnings: Add tests for all code changes - lint rules need snapshot tests in tests/specs/{group}/{rule}/.
🤖 Prompt for AI Agents
Verify each finding against the current code and only fix it if needed.

In `@crates/biome_js_analyze/tests/specs/nursery/useImportsFirst/valid.js` around
lines 1 - 5, Add a new valid fixture file (e.g., valid_with_directive.js) under
tests/specs/nursery/useImportsFirst/ that begins with a directive like "use
strict"; followed by the same import lines (import { foo } from "foo"; import {
bar } from "bar"; import { baz } from "baz"; const qux = 1;) and the same top
comment ("should not generate diagnostics") so the test suite captures that
directives are allowed by the useImportsFirst rule; ensure the file follows the
existing snapshot test pattern used in tests/specs/{group}/{rule}/ so it is
picked up by the rule tests.

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Inline comments:
In `@crates/biome_rule_options/src/use_imports_first.rs`:
- Line 6: Add a rustdoc comment above the public struct UseImportsFirstOptions
explaining what this options type configures (options for the
"use-imports-first" rule/assist), what each field would control (if currently
empty, state that it has no configurable fields yet and is reserved for future
settings), and include example usage or default behavior; ensure the doc uses
standard /// rustdoc format placed immediately before the declaration of
UseImportsFirstOptions.

---

Nitpick comments:
In `@crates/biome_js_analyze/tests/specs/nursery/useImportsFirst/valid.js`:
- Around line 1-5: Add a new valid fixture file (e.g., valid_with_directive.js)
under tests/specs/nursery/useImportsFirst/ that begins with a directive like
"use strict"; followed by the same import lines (import { foo } from "foo";
import { bar } from "bar"; import { baz } from "baz"; const qux = 1;) and the
same top comment ("should not generate diagnostics") so the test suite captures
that directives are allowed by the useImportsFirst rule; ensure the file follows
the existing snapshot test pattern used in tests/specs/{group}/{rule}/ so it is
picked up by the rule tests.

ℹ️ Review info

Configuration used: Path: .coderabbit.yaml

Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between 412a08d and c6d9702.

⛔ Files ignored due to path filters (7)

crates/biome_configuration/src/analyzer/linter/rules.rs is excluded by !**/rules.rs and included by **
crates/biome_diagnostics_categories/src/categories.rs is excluded by !**/categories.rs and included by **
crates/biome_js_analyze/tests/specs/nursery/useImportsFirst/invalid.js.snap is excluded by !**/*.snap and included by **
crates/biome_js_analyze/tests/specs/nursery/useImportsFirst/invalid_mixed.js.snap is excluded by !**/*.snap and included by **
crates/biome_js_analyze/tests/specs/nursery/useImportsFirst/valid.js.snap is excluded by !**/*.snap and included by **
crates/biome_js_analyze/tests/specs/nursery/useImportsFirst/valid_with_export.js.snap is excluded by !**/*.snap and included by **
packages/@biomejs/biome/configuration_schema.json is excluded by !**/configuration_schema.json and included by **

📒 Files selected for processing (7)

crates/biome_js_analyze/src/lint/nursery/use_imports_first.rs
crates/biome_js_analyze/tests/specs/nursery/useImportsFirst/invalid.js
crates/biome_js_analyze/tests/specs/nursery/useImportsFirst/invalid_mixed.js
crates/biome_js_analyze/tests/specs/nursery/useImportsFirst/valid.js
crates/biome_js_analyze/tests/specs/nursery/useImportsFirst/valid_with_export.js
crates/biome_rule_options/src/lib.rs
crates/biome_rule_options/src/use_imports_first.rs

crates/biome_rule_options/src/use_imports_first.rs

siketyan · 2026-02-28T10:25:18Z

Restore the PR template and fill it
Please add a changeset

dyc3

Looks good, just a couple notes

crates/biome_js_analyze/src/lint/nursery/use_imports_first.rs

crates/biome_js_analyze/tests/specs/nursery/useImportsFirst/invalid.js

codspeed-hq · 2026-02-28T20:07:39Z

Merging this PR will not alter performance

✅ 58 untouched benchmarks
⏩ 156 skipped benchmarks¹

_{Comparing terror:use-imports-first (70dec32) with main (edf8bb6)}

156 benchmarks were skipped, so the baseline results were used instead. If they were deleted from the codebase, click here and archive them to remove them from the performance reports. ↩

dyc3

Nice work!

feat(lint): add nursery rule useImportsFirst

c6d9702

github-actions bot added A-Project Area: project A-Linter Area: linter L-JavaScript Language: JavaScript and super languages A-Diagnostic Area: diagnostocis labels Feb 28, 2026

coderabbitai bot reviewed Feb 28, 2026

View reviewed changes

crates/biome_rule_options/src/use_imports_first.rs Show resolved Hide resolved

terror added 2 commits February 28, 2026 12:09

Add changeset

e5f5245

Merge branch 'main' into use-imports-first

e4594c0

dyc3 requested changes Feb 28, 2026

View reviewed changes

crates/biome_js_analyze/src/lint/nursery/use_imports_first.rs Show resolved Hide resolved

crates/biome_js_analyze/tests/specs/nursery/useImportsFirst/invalid.js Show resolved Hide resolved

terror added 2 commits February 28, 2026 12:21

fix(lint): add "why" note to useImportsFirst diagnostic

bb4718f

test(lint): add useImportsFirst test with all imports after statements

2a6ad5c

[autofix.ci] apply automated fixes

70dec32

github-actions bot added the A-CLI Area: CLI label Feb 28, 2026

dyc3 approved these changes Feb 28, 2026

View reviewed changes

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Uh oh!

feat(lint): add nursery rule `useImportsFirst`#9272

feat(lint): add nursery rule `useImportsFirst`#9272
terror wants to merge 6 commits intobiomejs:mainfrom
terror:use-imports-first

terror commented Feb 28, 2026 •

edited

Loading

Uh oh!

changeset-bot bot commented Feb 28, 2026 •

edited

Loading

Uh oh!

coderabbitai bot commented Feb 28, 2026 •

edited

Loading

Uh oh!

coderabbitai bot left a comment

Uh oh!

Uh oh!

siketyan commented Feb 28, 2026

Uh oh!

dyc3 left a comment

Uh oh!

Uh oh!

Uh oh!

codspeed-hq bot commented Feb 28, 2026 •

edited

Loading

Uh oh!

dyc3 left a comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

Uh oh!

Conversation

terror commented Feb 28, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Summary

Test Plan

Docs

Uh oh!

changeset-bot bot commented Feb 28, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

🦋 Changeset detected

Uh oh!

coderabbitai bot commented Feb 28, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Walkthrough

Suggested reviewers

Uh oh!

coderabbitai bot left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

siketyan commented Feb 28, 2026

Uh oh!

dyc3 left a comment

Choose a reason for hiding this comment

Uh oh!

Uh oh!

Uh oh!

codspeed-hq bot commented Feb 28, 2026 • edited Loading Uh oh! There was an error while loading. Please reload this page.

Uh oh!

Merging this PR will not alter performance

Footnotes

Uh oh!

dyc3 left a comment

Choose a reason for hiding this comment

Uh oh!

Reviewers

Assignees

Labels

Projects

Milestone

Development

Uh oh!

3 participants

terror commented Feb 28, 2026 •

edited

Loading

changeset-bot bot commented Feb 28, 2026 •

edited

Loading

coderabbitai bot commented Feb 28, 2026 •

edited

Loading

codspeed-hq bot commented Feb 28, 2026 •

edited

Loading