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>

1 files changed, 28 insertions, 0 deletions

diff --git a/crates/shirabe/src/installer/binary_installer.rs b/crates/shirabe/src/installer/binary_installer.rs
index a76f69e..ea73f6f 100644
--- a/crates/shirabe/src/installer/binary_installer.rs
+++ b/crates/shirabe/src/installer/binary_installer.rs
@@ -17,6 +17,34 @@ use crate::util::Platform;
 use crate::util::ProcessExecutor;
 use crate::util::Silencer;
 
+/// Seam over the BinaryInstaller methods reached through LibraryInstaller, so tests can inject a
+/// recording double. Composer has no PHP `BinaryInstallerInterface`; this exists only to allow the
+/// `LibraryInstaller` collaborator to be mocked the way PHPUnit mocks the concrete class.
+pub trait BinaryInstallerInterface: std::fmt::Debug {
+    fn install_binaries(
+        &mut self,
+        package: PackageInterfaceHandle,
+        install_path: &str,
+        warn_on_overwrite: bool,
+    );
+    fn remove_binaries(&mut self, package: PackageInterfaceHandle);
+}
+
+impl BinaryInstallerInterface for BinaryInstaller {
+    fn install_binaries(
+        &mut self,
+        package: PackageInterfaceHandle,
+        install_path: &str,
+        warn_on_overwrite: bool,
+    ) {
+        BinaryInstaller::install_binaries(self, package, install_path, warn_on_overwrite);
+    }
+
+    fn remove_binaries(&mut self, package: PackageInterfaceHandle) {
+        BinaryInstaller::remove_binaries(self, package);
+    }
+}
+
 /// Utility to handle installation of package "bin"/binaries
 #[derive(Debug)]
 pub struct BinaryInstaller {