test: port Composer tests unblocked by mockall, add seams

Port 11 categories of previously-ignored Composer tests now reachable with
the mockall crate: DownloadManager, VCS/Perforce/File downloaders,
VersionSelector, PlatformRepository, Auditor, installer/FilesystemRepository,
RootPackageLoader, util auth/http, commands, and Cache.

Extract test seams additively on concrete structs as *Interface traits
(Runtime, HhvmDetector, VersionGuesser, RepositorySet, Perforce,
BinaryInstaller) plus mock-field seams (Cache, Filesystem); consumers take
trait objects. Mocks are defined locally in the test crates via
mockall::mock!, since automock-generated mocks are cfg(test)-gated and
invisible across the integration-test boundary.

dataProviders are ported in full; tests blocked by unported shims stay
#[ignore] with documented reasons rather than reduced or weakened.

Fix product bugs surfaced by the ports:
- util/github: use the exception code, not the HTTP status, for 401/403
- advisory: serialize empty audit maps as [] to match PHP json_encode
- repository/filesystem and downloader/file: fix RefCell double-borrow panics

Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>

3 files changed, 30 insertions, 20 deletions

diff --git a/crates/shirabe/src/downloader/download_manager.rs b/crates/shirabe/src/downloader/download_manager.rs
index a5a83a6..b978368 100644
--- a/crates/shirabe/src/downloader/download_manager.rs
+++ b/crates/shirabe/src/downloader/download_manager.rs
@@ -532,6 +532,17 @@ impl DownloadManager {
         Ok(sources)
     }
 
+    /// For testing only: exposes the private `getAvailableSources` for the
+    /// DownloadManagerTest::testGetAvailableSourcesUpdateSticksToSameSource case,
+    /// which reaches it through `ReflectionMethod` in PHP.
+    pub fn __get_available_sources(
+        &self,
+        package: PackageInterfaceHandle,
+        prev_package: Option<PackageInterfaceHandle>,
+    ) -> Result<Vec<String>> {
+        self.get_available_sources(package, prev_package)
+    }
+
     /// Downloaders expect a /path/to/dir without trailing slash
     ///
     /// If any Installer provides a path with a trailing slash, this can cause bugs so make sure we remove them
diff --git a/crates/shirabe/src/downloader/file_downloader.rs b/crates/shirabe/src/downloader/file_downloader.rs
index b03db38..66f3390 100644
--- a/crates/shirabe/src/downloader/file_downloader.rs
+++ b/crates/shirabe/src/downloader/file_downloader.rs
@@ -124,18 +124,19 @@ impl FileDownloader {
         {
             // PHP: writeError('Running cache garbage collection', true, io_interface::VERY_VERBOSE)
             this.io.write_error("Running cache garbage collection");
-            cache.borrow_mut().gc(
-                this.config
-                    .borrow_mut()
-                    .get("cache-files-ttl")
-                    .as_int()
-                    .unwrap_or(0),
-                this.config
-                    .borrow_mut()
-                    .get("cache-files-maxsize")
-                    .as_int()
-                    .unwrap_or(0),
-            );
+            let ttl = this
+                .config
+                .borrow_mut()
+                .get("cache-files-ttl")
+                .as_int()
+                .unwrap_or(0);
+            let max_size = this
+                .config
+                .borrow_mut()
+                .get("cache-files-maxsize")
+                .as_int()
+                .unwrap_or(0);
+            cache.borrow_mut().gc(ttl, max_size);
         }
 
         this
diff --git a/crates/shirabe/src/downloader/perforce_downloader.rs b/crates/shirabe/src/downloader/perforce_downloader.rs
index f93cfa8..56d6957 100644
--- a/crates/shirabe/src/downloader/perforce_downloader.rs
+++ b/crates/shirabe/src/downloader/perforce_downloader.rs
@@ -12,6 +12,7 @@ use crate::package::PackageInterfaceHandle;
 use crate::repository::VcsRepository;
 use crate::util::Filesystem;
 use crate::util::Perforce;
+use crate::util::PerforceInterface;
 use crate::util::ProcessExecutor;
 use anyhow::Result;
 use indexmap::IndexMap;
@@ -20,7 +21,7 @@ use shirabe_php_shim::PhpMixed;
 #[derive(Debug)]
 pub struct PerforceDownloader {
     inner: VcsDownloaderBase,
-    pub(crate) perforce: Option<Perforce>,
+    pub(crate) perforce: Option<Box<dyn PerforceInterface>>,
 }
 
 impl PerforceDownloader {
@@ -61,20 +62,20 @@ impl PerforceDownloader {
         } else {
             None
         };
-        self.perforce = Some(Perforce::create(
+        self.perforce = Some(Box::new(Perforce::create(
             repo_config.unwrap_or_default(),
             url,
             path,
             self.inner.process.clone(),
             self.inner.io.clone(),
-        ));
+        )));
     }
 
     fn get_repo_config(&self, repository: &VcsRepository) -> IndexMap<String, PhpMixed> {
         repository.get_repo_config().clone()
     }
 
-    pub fn set_perforce(&mut self, perforce: Perforce) {
+    pub fn set_perforce(&mut self, perforce: Box<dyn PerforceInterface>) {
         self.perforce = Some(perforce);
     }
 }
@@ -135,10 +136,7 @@ impl VcsDownloader for PerforceDownloader {
         self.perforce.as_mut().unwrap().p4_login();
         self.perforce.as_mut().unwrap().write_p4_client_spec();
         self.perforce.as_mut().unwrap().connect_client();
-        self.perforce
-            .as_mut()
-            .unwrap()
-            .sync_code_base(label.as_deref());
+        self.perforce.as_mut().unwrap().sync_code_base(label);
         self.perforce.as_mut().unwrap().cleanup_client_spec();
 
         Ok(None)