fix(core): place a top-level imported file's leading /*! banner at the head, not the tail

[matthew-dean]

While measuring bootstrap4 render parity, the license banner came out at the end of the output instead of line 1.

Root cause: a leading block comment that opens an imported document is spliced at the import site only when the import is nested (e.depth > 0). A top-level @import (bootstrap4's entry is a single @import "bootstrap-less-port/less/bootstrap", and that file opens with the /*! Bootstrap v4.1.1 … */ banner) is at e.depth === 0, so the banner was left unemitted at the splice and swept to the output tail. The importing document's own leading-comment pass reads the importer's trivia, never the loaded file's, so the e.depth > 0 guard was wrong.

Fix: emit the imported document's leading block comment at the splice for depth 0 too (still gated to non-reference imports). Banner now renders as line 1.

Regression test: imported-leading-comment.test.ts (top-level import of a file whose leading /*! banner must appear at the head, exactly once). Full core (3296) and jess suites stay green.

Context: this is the one genuine parity gap found in the bootstrap4 render triage — the remaining diff vs the lessc 4.x oracle is the intentional v5 :is() compaction and the settled V7 number precision (owner-confirmed accepted divergences).

[coderabbitai]

Important

Review skipped

Auto reviews are disabled on base/target branches other than the default branch.

Please check the settings in the CodeRabbit UI or the .coderabbit.yaml file in this repository. To trigger a single review, invoke the @coderabbitai review command.

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Team

Run ID: 495cdee1-0e55-467f-96ec-57fbbeabafec

You can disable this status message by setting the reviews.review_status to false in the CodeRabbit configuration file.

Use the checkbox below for a quick retry:

• 🔍 Trigger review

---

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

• X
• Mastodon
• Reddit
• LinkedIn

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