test(tests): port setUp/tearDown as set_up/tear_down with TearDown

Port PHP setUp/tearDown across the ported integration tests using
same-named set_up()/tear_down() functions and a TearDown struct whose
Drop runs tear_down(). Fixture-init setUp returns its fixtures;
tmpdir-style setUp/tearDown carry state in TearDown fields. Parts that
depend on unported infrastructure (PHPUnit mocks, Config::merge, the PHP
error handler) stay todo!() and are only wired into ignored stubs to
avoid breaking live tests.

Also fix shirabe-php-shim putenv to handle the no-'=' form (PHP unsets
the variable), which Platform::clear_env relies on for the env-clearing
tearDowns.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

1 files changed, 21 insertions, 0 deletions

diff --git a/crates/shirabe/tests/plugin/plugin_installer_test.rs b/crates/shirabe/tests/plugin/plugin_installer_test.rs
index 4fed7c6..1243a49 100644
--- a/crates/shirabe/tests/plugin/plugin_installer_test.rs
+++ b/crates/shirabe/tests/plugin/plugin_installer_test.rs
@@ -1,5 +1,26 @@
 //! ref: composer/tests/Composer/Test/Plugin/PluginInstallerTest.php
 
+/// Builds the Composer instance from mocked DownloadManager/RepositoryManager/
+/// InstallationManager/EventDispatcher and an InstalledRepository mock, plus the
+/// plugin fixtures temp directory. The mocks and the plugin machinery are not
+/// available here, so this remains a stub.
+fn set_up() {
+    todo!()
+}
+
+/// Removes the fixtures directory created by `set_up`, which is itself a stub.
+fn tear_down() {
+    todo!()
+}
+
+struct TearDown;
+
+impl Drop for TearDown {
+    fn drop(&mut self) {
+        tear_down();
+    }
+}
+
 // The plugin system requires the PHP runtime to load and instantiate plugin classes; the
 // PluginManager/PluginInstaller is intentionally not implemented yet (TODO(plugin)).
 macro_rules! stub {