fix(event-dispatcher): run COMPOSER_BINARY without a PHP interpreter

`@composer <args>` and a bare `composer <args>` script both re-enter the
binary running the script, taken from COMPOSER_BINARY. That path used to
be prefixed with the PHP interpreter command, which produced
`php <shirabe path> install` and could not run: Shirabe ships as a native
executable, not a phar.

Co-Authored-By: Claude Opus 5 (1M context) <noreply@anthropic.com>

1 files changed, 48 insertions, 0 deletions

diff --git a/crates/shirabe/tests/event_dispatcher/event_dispatcher_test.rs b/crates/shirabe/tests/event_dispatcher/event_dispatcher_test.rs
index 90df0624..2c74768a 100644
--- a/crates/shirabe/tests/event_dispatcher/event_dispatcher_test.rs
+++ b/crates/shirabe/tests/event_dispatcher/event_dispatcher_test.rs
@@ -36,6 +36,7 @@ use shirabe_symfony_console::output::output_interface;
 fn tear_down() {
     Platform::clear_env("COMPOSER_SKIP_SCRIPTS");
     Platform::clear_env("PHP_BINARY");
+    Platform::clear_env("COMPOSER_BINARY");
 }
 
 struct TearDown;
@@ -977,3 +978,50 @@ fn test_dispatcher_outputs_error_on_failed_command() {
     );
     assert_eq!(expected, io.borrow().get_output());
 }
+
+/// Both `@composer <args>` and a bare `composer <args>` script re-enter the binary that is running
+/// the script, taken from COMPOSER_BINARY. That binary is a native executable, so it is run
+/// directly rather than being passed to a PHP interpreter.
+#[test]
+#[serial]
+fn test_dispatcher_runs_composer_scripts_through_the_running_binary() {
+    let _tear_down = TearDown;
+
+    Platform::put_env("COMPOSER_BINARY", "/path/to/shirabe");
+    let binary = ProcessExecutor::escape("/path/to/shirabe");
+
+    let (process, _process_guard) = get_process_executor_mock(
+        vec![
+            cmd(format!("{} install --no-dev", binary)),
+            cmd(format!("{} update", binary)),
+        ],
+        true,
+        MockHandler::default(),
+    );
+
+    let composer = create_composer_instance();
+    let io = buffer_io_verbose();
+    let io_dyn: std::rc::Rc<std::cell::RefCell<dyn IOInterface>> = io.clone();
+
+    let mut dispatcher = dispatcher_with_listeners(
+        &composer,
+        io_dyn,
+        process,
+        listeners_const(vec!["@composer install --no-dev", "composer update"]),
+    );
+
+    dispatcher
+        .dispatch_script(
+            ScriptEvents::POST_INSTALL_CMD,
+            false,
+            vec![],
+            IndexMap::new(),
+        )
+        .unwrap();
+
+    let expected = format!(
+        "> post-install-cmd: @composer install --no-dev{eol}> post-install-cmd: composer update{eol}",
+        eol = PHP_EOL,
+    );
+    assert_eq!(expected, io.borrow().get_output());
+}