fix: detect .zip bundles in archive mode (apm pack default changed to zip)

[danielmeppiel]

Why

The APM CLI intentionally and permanently flipped its apm pack --archive default output format from .tar.gz to .zip (src/apm_cli/bundle/packer.py: archive_format: str = "zip", with --archive-format tar.gz as the opt-out). This action's bundle detection still only matched .tar.gz, so packing with a current CLI fails with apm pack produced no bundle even though the CLI did produce a valid .zip bundle.

Empirical evidence

Failing job: microsoft/apm GH-AW Compatibility (build-release.yml → gh-aw-compat) on tag v0.21.0 — run 27832510355, job 82376879301.

[*] Packed 8 file(s) -> /tmp/gh-aw-compat-test/build/inline-workflow-1.0.0.zip
[i] Note: --archive now produces .zip by default. Use --archive-format tar.gz to ...
##[error]APM action failed: apm pack produced no bundle.

The fix belongs here in apm-action, not the CLI — the CLI default is deliberate.

Root cause

src/bundler.ts → findBundleOrNull(buildDir, archive). The archive branch filtered e.endsWith('.tar.gz') only, so a .zip emit produced an empty list → null → caller throws "apm pack produced no bundle."

The fix (one line of detection)

const archives = entries.filter(e => e.endsWith('.zip') || e.endsWith('.tar.gz')).sort();

• Keeps the single-candidate guarantee; the multiple-archive error message is now format-agnostic: "Multiple archive bundles found in build directory after apm pack: ...".
• Directory-mode behavior unchanged. tar.gz support intact (still valid via --archive-format tar.gz; bundles-file/restore paths in multibundle.ts still use .tar.gz).
• installer.ts (apm-<suffix>.tar.gz binary download) and release.ts matrix-pack tar.gz logic untouched.

Doc-string corrections (action.yml)

• pack input: now states archive: true follows the CLI default and produces .zip, with .tar.gz still supported via the CLI opt-out.
• archive input: reworded from "Produce .tar.gz instead of directory" to reflect the .zip default.

Tests

Extended src/__tests__/bundler.test.ts (runPackStep suite):

• detects a .zip bundle in archive mode,
• still detects a .tar.gz bundle in archive mode,
• still throws on multiple archive candidates (now with the format-agnostic message).

Build + verify

This is a compiled action — dist/ was rebuilt and committed.

• npm ci ✅
• npm run typecheck ✅
• npm run lint ✅
• npm run build (regenerates dist/index.js) ✅ — dist/index.js committed
• dist-drift check (CI's git diff --name-only dist/) ✅ — no drift after commit
• npm test ✅ — 184 passed, 5 suites

Co-authored-by: Copilot 223556219+Copilot@users.noreply.github.com

[Copilot]

Pull request overview

Fixes the action’s bundle discovery logic to remain compatible with the APM CLI’s apm pack --archive default changing from producing .tar.gz to producing .zip, and updates tests/docs accordingly.

Changes:

• Update findBundleOrNull(..., archive=true) to detect both .zip and .tar.gz outputs and make the “multiple archive” error message format-agnostic.
• Extend runPackStep tests to cover .zip detection, keep .tar.gz coverage, and update the multi-archive assertion message.
• Update action.yml input descriptions to reflect the CLI’s new default, and rebuild dist/index.js.

Show a summary per file

File	Description
src/bundler.ts	Detect .zip and .tar.gz bundle artifacts in archive mode; improve ambiguity error message.
src/tests/bundler.test.ts	Add/adjust tests to validate .zip detection and updated multi-archive error messaging.
dist/index.js	Rebuilt compiled action output reflecting the source changes.
action.yml	Update input documentation to reflect .zip archive default behavior.

Copilot's findings

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• Files reviewed: 3/4 changed files
• Comments generated: 2

[danielmeppiel]

Closing as superseded by #47, which predates this PR and fixes the same root cause (apm pack --archive default flipped to .zip) more completely.

#47 fixes the .zip break across all three affected surfaces; this PR only addressed findBundleOrNull (the pack-detection path / the failing gh-aw-compat job). The two surfaces left unfixed here are covered by #47:

• detectBundleFormat — restore uses tar tzf, which can't read a .zip on GNU tar (Linux runners), so restoring a .zip bundle would still throw.
• parseBundleListFile (multibundle.ts) — a bundles-file entry ending in .zip is hard-rejected.

Merging #47 instead.