test(ext-nodemailer): link-only shims so the crate's unit tests link without perry-stdlib

changelog.d/11429-ext-nodemailer-test-link.md

@@ -0,0 +1 @@
+**test(ext-nodemailer): the crate's unit tests link again.** `#[cfg(test)]` link-only shims stand in for the perry-stdlib `js_perry_smtp_*` seam and the `perry_ffi_promise_*` bridge. `cargo test -p perry-ext-nodemailer --lib` had failed to link since #10354, which reddened every full-scope cargo-test run.

crates/perry-ext-nodemailer/src/lib.rs

@@ -228,6 +228,9 @@ pub extern "C" fn js_nodemailer_verify(transporter_handle: Handle) -> *mut Promi
     raw
 }
 
+#[cfg(test)]
+mod test_link_shims;
+
 #[cfg(test)]
 mod tests {
     use super::*;

crates/perry-ext-nodemailer/src/test_link_shims.rs

@@ -0,0 +1,119 @@
+//! Link-only stand-ins for symbols a unit-test binary cannot resolve.
+//!
+//! In a real program this wrapper is co-linked with perry-stdlib, which
+//! defines the `js_perry_smtp_*` transport seam and the `perry_ffi_promise_*`
+//! async bridge. A `cargo test -p perry-ext-nodemailer` binary links neither,
+//! yet `turnloop_bridge` and `perry_ffi::JsPromise` reference them, so the
+//! test binary failed to link at all (#10354 introduced the seam). No unit
+//! test reaches the transport or settles a promise: `available()` answers
+//! "no engine" and everything else aborts loudly if a future test ever does,
+//! instead of silently pretending a mail was sent (same approach as
+//! perry-ext-events' `test_async_shims`).
+
+use perry_ffi::Promise;
+use std::ffi::c_void;
+
+fn unreachable_in_unit_tests(symbol: &str) -> ! {
+    eprintln!(
+        "{symbol} was called from a perry-ext-nodemailer unit test; the real \
+         symbol lives in perry-stdlib, which unit-test binaries do not link"
+    );
+    std::process::abort()
+}
+
+#[no_mangle]
+pub extern "C" fn js_perry_smtp_available() -> i32 {
+    0
+}
+
+#[no_mangle]
+pub extern "C" fn js_perry_smtp_begin() -> i64 {
+    unreachable_in_unit_tests("js_perry_smtp_begin")
+}
+
+#[no_mangle]
+pub extern "C" fn js_perry_smtp_set_server(
+    _draft: i64,
+    _host_ptr: *const u8,
+    _host_len: usize,
+    _port: u16,
+    _implicit_tls: i32,
+    _require_tls: i32,
+) {
+    unreachable_in_unit_tests("js_perry_smtp_set_server")
+}
+
+#[no_mangle]
+pub extern "C" fn js_perry_smtp_set_auth(
+    _draft: i64,
+    _user_ptr: *const u8,
+    _user_len: usize,
+    _pass_ptr: *const u8,
+    _pass_len: usize,
+) {
+    unreachable_in_unit_tests("js_perry_smtp_set_auth")
+}
+
+#[no_mangle]
+pub extern "C" fn js_perry_smtp_set_from(_draft: i64, _ptr: *const u8, _len: usize) {
+    unreachable_in_unit_tests("js_perry_smtp_set_from")
+}
+
+#[no_mangle]
+pub extern "C" fn js_perry_smtp_add_recipient(_draft: i64, _ptr: *const u8, _len: usize) {
+    unreachable_in_unit_tests("js_perry_smtp_add_recipient")
+}
+
+#[no_mangle]
+pub extern "C" fn js_perry_smtp_set_message(
+    _draft: i64,
+    _id_ptr: *const u8,
+    _id_len: usize,
+    _body_ptr: *const u8,
+    _body_len: usize,
+) {
+    unreachable_in_unit_tests("js_perry_smtp_set_message")
+}
+
+#[no_mangle]
+pub extern "C" fn js_perry_smtp_submit(
+    _draft: i64,
+    _verify: i32,
+    _ctx: usize,
+    _done: extern "C" fn(usize, *const c_void),
+) -> i32 {
+    unreachable_in_unit_tests("js_perry_smtp_submit")
+}
+
+#[no_mangle]
+pub extern "C" fn js_perry_smtp_cancel(_draft: i64) {
+    unreachable_in_unit_tests("js_perry_smtp_cancel")
+}
+
+#[no_mangle]
+pub extern "C" fn perry_ffi_promise_new() -> *mut Promise {
+    unreachable_in_unit_tests("perry_ffi_promise_new")
+}
+
+#[no_mangle]
+pub extern "C" fn perry_ffi_promise_resolve_bits(_promise: *mut Promise, _bits: u64) {
+    unreachable_in_unit_tests("perry_ffi_promise_resolve_bits")
+}
+
+#[no_mangle]
+pub extern "C" fn perry_ffi_promise_reject_deferred(
+    _promise: *mut Promise,
+    _ctx: *mut c_void,
+    _invoke: extern "C" fn(*mut c_void) -> u64,
+) {
+    unreachable_in_unit_tests("perry_ffi_promise_reject_deferred")
+}
+
+#[no_mangle]
+pub extern "C" fn perry_ffi_promise_resolve_deferred(
+    _promise: *mut Promise,
+    _ctx: *mut c_void,
+    _invoke: extern "C" fn(*mut c_void) -> u64,
+) {
+    unreachable_in_unit_tests("perry_ffi_promise_resolve_deferred")
+}