fix(fastify): forward dynamic request/reply property reads in external-fastify variant builds (#5037)

[proggeramlug]

Summary

Fixes #5037 — a fastify request object passed into a plain helper function reads request.headers === undefined (→ fastify 500), but only in auto-optimize variant builds. The same source against the prebuilt release libs works.

Root cause

The compiler binary is identical between prebuilt and auto-optimize modes — only the linked runtime/ext static libs differ by cargo feature flags. For a program importing fastify, auto-optimize triggers the well-known-bindings flip: import 'fastify' is routed to perry-ext-fastify, bundled-fastify/http-server are stripped, and external-fastify-pump is activated (see optimized_libs.rs and well_known_bindings.toml).

The bundled FastifyContext property-dispatch arm in js_handle_property_dispatch (crates/perry-stdlib/src/common/dispatch.rs) is gated on #[cfg(feature = "http-server")], so in the flipped build it is compiled out. When a request/reply handle escapes into a user helper, its static type is erased and codegen emits a generic dynamic property read here rather than a NativeMethodCall — and there was no external-fastify dispatch arm to handle it, so the read fell through to undefined. Inline reads in the handler still worked because codegen recognised the receiver and called js_fastify_req_* directly.

perry-ext-fastify already exports the membership probe js_ext_fastify_is_context_handle precisely for this path (its doc comment claims "perry-stdlib's js_handle_property_dispatch arms call this") — but the stdlib arm was never wired up, unlike the equivalent external-zlib and external-net arms.

Fix

Add the missing external-fastify property-dispatch arm, gated on all(feature = "external-fastify-pump", not(feature = "http-server")) (the same gate the external-fastify-pump pump uses in async_bridge.rs). It probes js_ext_fastify_is_context_handle and forwards query/params/body/rawBody/text/headers/method/url/user to the same js_fastify_req_* exports the bundled arm uses. The extern symbols resolve at link time from perry-ext-fastify, mirroring the established external-zlib-pump / external-net-pump probe-and-forward arms.

Validation

• cargo check -p perry-stdlib (default config — new arm compiled out under http-server): clean.
• cargo check -p perry-stdlib --no-default-features --features external-fastify-pump (the flipped/auto-optimize config — new arm compiled in): clean. This config is not exercised by CI, so it was verified locally.

Note: macOS host builds don't reproduce the original bug because their auto-optimize variant set keeps the bundled fastify path (no flip); the linux worker pipeline does flip. No version bump / changelog per maintainer (folded in at squash-merge).

Summary by CodeRabbit

• New Features
  • Improved Fastify request/reply property dispatch for the external-fastify integration, including better support for common fields like query, params, body/raw body, headers, method, URL, and user data.
• Chores / Refactor
  • Reformatted Android linker and NDK clang executable name construction for the Windows host case, preserving the same output behavior.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

⚙️ Run configuration

Configuration used: defaults

Review profile: CHILL

Plan: Pro Plus

Run ID: 3e20be30-a2cd-4e8c-ae05-b43b5270c4e8

📥 Commits

Reviewing files that changed from the base of the PR and between a953a04 and 4dd0910.

📒 Files selected for processing (2)

• crates/perry/src/commands/compile/link/mod.rs
• crates/perry/src/commands/compile/link/platform_cmd.rs

✅ Files skipped from review due to trivial changes (2)

• crates/perry/src/commands/compile/link/mod.rs
• crates/perry/src/commands/compile/link/platform_cmd.rs

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📝 Walkthrough

Walkthrough

A new external-fastify-pump-gated branch is added to js_handle_property_dispatch that routes request/reply property reads through external symbols to preserve object properties across function call boundaries. Two Android NDK clang path construction sites reformat their Windows conditional suffix from single-line to multi-line without functional change.

Changes

External-fastify handle property dispatch

Layer / File(s)

Summary

external-fastify-pump property dispatch arm crates/perry-stdlib/src/common/dispatch.rs

Adds 69 lines inside js_handle_property_dispatch: an external-fastify-pump (non-http-server) feature gate that probes handle membership via js_ext_fastify_is_context_handle, then dispatches each supported request/reply property name to the matching js_fastify_req_* external function, guards string-pointer returns against null by emitting undefined, and returns undefined as the fallback for unknown property names.

Android NDK clang path formatting

Layer / File(s)	Summary
Multi-line Windows conditional formatting crates/perry/src/commands/compile/link/mod.rs, crates/perry/src/commands/compile/link/platform_cmd.rs	Reformats the Windows host-tag conditional suffix (.cmd appended on Windows, empty otherwise) used in Android NDK clang executable path construction from single-line cfg! macros into multi-line if/else expressions across both linker configuration files, preserving behavior and improving readability.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~12 minutes

Possibly related PRs

• PerryTS/perry#5154: Contains matching Android NDK clang path construction reformatting changes in the same two linker configuration files for Windows host toolchain invocation.

Poem

🐇 Hop-hop through the dispatch gate,
A feature flag seals each handle's fate.
request.headers once went astray—
Across a function call, lost on the way.
Now ext-fastify probes the context right,
And every property returns to light! ✨

🚥 Pre-merge checks | ✅ 4 | ❌ 1

❌ Failed checks (1 inconclusive)

Check name	Status	Explanation	Resolution
Out of Scope Changes check	❓ Inconclusive	The main fix to dispatch.rs directly addresses #5037, but secondary formatting changes to link/mod.rs and platform_cmd.rs appear to be pre-existing rustfmt-dirty issues rather than necessary for the core fix.	Clarify whether the formatting changes to link/mod.rs and platform_cmd.rs are necessary for the PR or unrelated style cleanup that should be separated.

✅ Passed checks (4 passed)

Check name	Status	Explanation
Title check	✅ Passed	The title clearly and specifically summarizes the primary change: adding external-fastify variant support for dynamic request/reply property reads, addressing the core issue #5037.
Description check	✅ Passed	The description comprehensively covers the summary, root cause analysis, the fix, and validation results, aligning with the repository's template requirements.
Linked Issues check	✅ Passed	The PR fully addresses issue #5037 by implementing the missing external-fastify property-dispatch arm to forward dynamic property reads, resolving the undefined property issue in auto-optimize variant builds.
Docstring Coverage	✅ Passed	Docstring coverage is 100.00% which is sufficient. The required threshold is 80.00%.

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✨ Finishing Touches

📝 Generate docstrings

• Create stacked PR
• Commit on current branch

🧪 Generate unit tests (beta)

• Create PR with unit tests
• Commit unit tests in branch fix/5037-fastify-request-props

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[proggeramlug]

End-to-end verification (auto-optimize variant, reproduced on macOS host)

The well-known flip does trigger on this host once the prebuilt ext lib isn't short-circuited — the compiler logs the same variant as the issue:

well-known: routing `fastify` → rebuilding `perry-ext-fastify` ...
auto-optimize: rebuilding runtime+stdlib (features=async-runtime,crypto,external-fastify-pump)
auto-optimize: built .../libperry_runtime.a / libperry_stdlib.a / libperry_ext_fastify.a

Ran the issue's exact repro against that binary:

build	/direct	/helper
without this fix (origin/main stdlib)	{"auth":"Bearer abc"}	{"statusCode":500,..."Cannot read properties of undefined (reading 'authorization')"}
with this fix	{"auth":"Bearer abc"}	{"auth":"Bearer abc"} ✅

The negative control rebuilt only libperry_stdlib.a (the changed crate), confirming the arm is exactly what was missing.

Note on the second commit

The style: commit just runs cargo fmt over the two #5154 Android-NDK .cmd lines that main currently leaves rustfmt-dirty — without it this PR's lint gate stays red on a pre-existing main issue unrelated to the fix. No behaviour change.