fix: should use external source as name hint

[JSerFeng]

Summary

should use external import source as the symbol name hint, instead of readable identifier, and do not render unnecessary empty import brackets

Related links

Checklist

• Tests updated (or not required).
• Documentation updated (or not required).

[Copilot]

Pull Request Overview

This PR fixes the naming convention for external imports in ESM output by using the external source as the name hint instead of readable identifiers, and improves import statement rendering to avoid unnecessary empty import brackets.

• Changes external import symbol naming to use source names (e.g., "fs" → "fs_0") instead of readable identifiers (e.g., "external_fs_")
• Updates import statement formatting to conditionally render brackets only when there are named imports
• Adds proper spacing and comma handling for mixed default and named imports

Reviewed Changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
crates/rspack_plugin_esm_library/src/link.rs	Updates external import name resolution to use source instead of readable_identifier
crates/rspack_plugin_esm_library/src/render.rs	Improves import statement formatting with conditional bracket rendering and proper spacing
tests/rspack-test/esmOutputCases/externals/externals-import-render/rspack.config.js	Adds test configuration for external module imports
tests/rspack-test/esmOutputCases/externals/externals-import-render/index.js	Adds test case for mixed default and named imports
tests/rspack-test/esmOutputCases/externals/externals-import-render/__snapshots__/esm.snap.txt	Test snapshot showing clean import formatting without empty brackets
tests/rspack-test/esmOutputCases/re-exports/re-export-external/__snapshots__/esm.snap.txt	Updated snapshot reflecting new naming convention and export ordering

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[github-actions]

📦 Binary Size-limit

Comparing a0367e0 to chore(deps): update swc (#11747) by renovate[bot]

❌ Size increased by 5.38KB from 47.89MB to 47.89MB (⬆️0.01%)

[codspeed-hq]

CodSpeed Performance Report

Merging #11825 will not alter performance

_{Comparing esm-lib-plugin (a0367e0) with main (ed1f1fa)}

Summary

✅ 17 untouched