refactor(promise): rewrite promise bodies to async/await

Mechanically convert promise-returning function bodies to async/await:
resolve() returns the value directly, forwarding calls get .await, and
simple .then chains become await sequences. Also collapse the installer
double-Option (Result<Option<Option<PhpMixed>>> -> Result<Option<PhpMixed>>).

Hard spots that depend on the Loop::wait / job-machine boundary
(accept/reject orchestration, closures capturing &mut self, batch waits)
are left intact and marked with TODO(phase-c-promise) for manual porting.
The crate does not compile yet; traits still need #[async_trait].

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>

6 files changed, 82 insertions, 136 deletions

diff --git a/crates/shirabe/src/installer/installation_manager.rs b/crates/shirabe/src/installer/installation_manager.rs
index 114f1fc..ae0470a 100644
--- a/crates/shirabe/src/installer/installation_manager.rs
+++ b/crates/shirabe/src/installer/installation_manager.rs
@@ -285,6 +285,8 @@ impl InstallationManager {
         download_only: bool,
         all_operations: Vec<Box<dyn OperationInterface>>,
     ) -> Result<()> {
+        // TODO(phase-c-promise): Loop::wait-driven batch orchestration (download/cleanup promises);
+        // rewrite to await collected futures once the async Loop boundary lands.
         let mut promises: Vec<Box<dyn PromiseInterface>> = vec![];
 
         for (index, operation) in &operations {
@@ -401,6 +403,8 @@ impl InstallationManager {
         run_scripts: bool,
         all_operations: &[Box<dyn OperationInterface>],
     ) -> Result<()> {
+        // TODO(phase-c-promise): Loop::wait-driven batch orchestration (prepare/install promises);
+        // rewrite to await collected futures once the async Loop boundary lands.
         let mut promises: Vec<Box<dyn PromiseInterface>> = vec![];
         let mut post_exec_callbacks: Vec<Box<dyn Fn()>> = vec![];
 
@@ -513,6 +517,7 @@ impl InstallationManager {
 
     /// @param array<PromiseInterface<void|null>> $promises
     fn wait_on_promises(&mut self, promises: Vec<Box<dyn PromiseInterface>>) {
+        // TODO(phase-c-promise): thin wrapper over Loop::wait (the async boundary owned separately).
         let mut progress: Option<()> = None;
         // TODO(phase-b): self.io instanceof ConsoleIO downcast
         let io_is_console = false;
@@ -541,7 +546,7 @@ impl InstallationManager {
     /// @phpstan-return PromiseInterface<void|null>|null
     pub async fn download(&mut self, package: &dyn PackageInterface) -> Option<PhpMixed> {
         let installer = self.get_installer(package.get_type()).ok()?;
-        let promise = installer.cleanup("install", package, None).ok()?;
+        let promise = installer.cleanup("install", package, None).await.ok()?;
 
         promise
     }
@@ -556,7 +561,7 @@ impl InstallationManager {
     ) -> Option<PhpMixed> {
         let package = operation.get_package();
         let installer = self.get_installer(package.get_type()).ok()?;
-        let promise = installer.install(repo, package).ok()?;
+        let promise = installer.install(repo, package).await.ok()?;
         self.mark_for_notification(package);
 
         promise
@@ -578,24 +583,19 @@ impl InstallationManager {
 
         let promise = if initial_type == target_type {
             let installer = self.get_installer(initial_type).ok()?;
-            let promise = installer.update(repo, initial, target).ok()?;
+            let promise = installer.update(repo, initial, target).await.ok()?;
             self.mark_for_notification(target);
             promise
         } else {
-            let promise = self
+            // PHP: uninstall initial, then install target via the target-type installer.
+            let _ = self
                 .get_installer(initial_type)
                 .ok()?
                 .uninstall(repo, initial)
+                .await
                 .ok()?;
-            let promise = match promise {
-                Some(p) => p,
-                None => promise::resolve(None),
-            };
-
-            let target_type = target_type.to_string();
-            // TODO(phase-b): promise.then(closure capturing self/installer)
-            let _ = target_type;
-            Some(promise)
+            let installer = self.get_installer(target_type).ok()?;
+            installer.install(repo, target).await.ok()?
         };
 
         promise
@@ -612,7 +612,7 @@ impl InstallationManager {
         let package = operation.get_package();
         let installer = self.get_installer(package.get_type()).ok()?;
 
-        installer.uninstall(repo, package).ok()?
+        installer.uninstall(repo, package).await.ok()?
     }
 
     /// Executes markAliasInstalled operation.
@@ -653,6 +653,8 @@ impl InstallationManager {
     }
 
     pub fn notify_installs(&mut self, _io: &dyn IOInterface) {
+        // TODO(phase-c-promise): collects http_downloader.add() promises and drives them via Loop::wait;
+        // rewrite to await the collected futures once the async Loop boundary lands.
         let mut promises: Vec<Box<dyn PromiseInterface>> = vec![];
 
         let result: Result<()> = (|| -> Result<()> {
@@ -802,6 +804,8 @@ impl InstallationManager {
         &mut self,
         cleanup_promises: &IndexMap<i64, Box<dyn Fn() -> Option<Box<dyn PromiseInterface>>>>,
     ) {
+        // TODO(phase-c-promise): runs cleanup closures and drives them via Loop::wait;
+        // rewrite once the async Loop boundary and async cleanup closures land.
         let mut promises: Vec<Box<dyn PromiseInterface>> = vec![];
 
         self.loop_.borrow().abort_jobs();
diff --git a/crates/shirabe/src/installer/library_installer.rs b/crates/shirabe/src/installer/library_installer.rs
index a9a77e9..0629de5 100644
--- a/crates/shirabe/src/installer/library_installer.rs
+++ b/crates/shirabe/src/installer/library_installer.rs
@@ -137,11 +137,10 @@ impl LibraryInstaller {
     ) -> Result<Option<PhpMixed>> {
         let download_path = self.get_install_path(package).unwrap();
 
-        Ok(Some(
-            self.get_download_manager()
-                .borrow()
-                .install(package, &download_path)?,
-        ))
+        self.get_download_manager()
+            .borrow()
+            .install(package, &download_path)
+            .await
     }
 
     /// @return PromiseInterface|null
@@ -159,19 +158,9 @@ impl LibraryInstaller {
             if strpos(&initial_download_path, &target_download_path) == Some(0)
                 || strpos(&target_download_path, &initial_download_path) == Some(0)
             {
-                let promise = self.remove_code(initial)?;
-                let promise = match promise {
-                    Some(p) => p,
-                    None => shirabe_external_packages::react::promise::resolve(None),
-                };
-
-                // TODO(phase-b): promise.then expects Option<Box<dyn FnOnce(Option<PhpMixed>) -> Option<PhpMixed>>>
-                // arguments. Translating the original PHP closure (which captures &self and target)
-                // requires restructuring; tracked separately.
-                let _ = promise;
-                return Ok(Some(todo!(
-                    "promise.then(...) chain to install_code(target)"
-                )));
+                // PHP: return $this->removeCode($initial)->then(fn () => $this->installCode($target));
+                let _ = self.remove_code(initial).await?;
+                return self.install_code(target).await;
             }
 
             self.filesystem
@@ -179,11 +168,10 @@ impl LibraryInstaller {
                 .rename(&initial_download_path, &target_download_path);
         }
 
-        Ok(Some(self.get_download_manager().borrow().update(
-            initial,
-            target,
-            &target_download_path,
-        )?))
+        self.get_download_manager()
+            .borrow()
+            .update(initial, target, &target_download_path)
+            .await
     }
 
     /// @return PromiseInterface|null
@@ -194,11 +182,10 @@ impl LibraryInstaller {
     ) -> Result<Option<PhpMixed>> {
         let download_path = self.get_package_base_path(package);
 
-        Ok(Some(
-            self.get_download_manager()
-                .borrow()
-                .remove(package, &download_path)?,
-        ))
+        self.get_download_manager()
+            .borrow()
+            .remove(package, &download_path)
+            .await
     }
 
     pub(crate) fn initialize_vendor_dir(&mut self) {
@@ -275,11 +262,10 @@ impl InstallerInterface for LibraryInstaller {
         // self.initialize_vendor_dir();
         let download_path = self.get_install_path(package).unwrap();
 
-        Ok(Some(self.get_download_manager().borrow().download(
-            package,
-            &download_path,
-            prev_package,
-        )?))
+        self.get_download_manager()
+            .borrow()
+            .download(package, &download_path, prev_package)
+            .await
     }
 
     async fn prepare(
@@ -292,12 +278,10 @@ impl InstallerInterface for LibraryInstaller {
         // self.initialize_vendor_dir();
         let download_path = self.get_install_path(package).unwrap();
 
-        Ok(Some(self.get_download_manager().borrow().prepare(
-            r#type,
-            package,
-            &download_path,
-            prev_package,
-        )?))
+        self.get_download_manager()
+            .borrow()
+            .prepare(r#type, package, &download_path, prev_package)
+            .await
     }
 
     async fn cleanup(
@@ -310,12 +294,10 @@ impl InstallerInterface for LibraryInstaller {
         // self.initialize_vendor_dir();
         let download_path = self.get_install_path(package).unwrap();
 
-        Ok(Some(self.get_download_manager().borrow().cleanup(
-            r#type,
-            package,
-            &download_path,
-            prev_package,
-        )?))
+        self.get_download_manager()
+            .borrow()
+            .cleanup(r#type, package, &download_path, prev_package)
+            .await
     }
 
     async fn install(
@@ -332,6 +314,7 @@ impl InstallerInterface for LibraryInstaller {
             self.binary_installer.remove_binaries(package);
         }
 
+        // TODO(phase-c-promise): rewrite install_code().then(installBinaries + repo.addPackage) as an await sequence.
         let promise = self.install_code(package)?;
         let promise = match promise {
             Some(p) => p,
@@ -365,6 +348,7 @@ impl InstallerInterface for LibraryInstaller {
         // self.initialize_vendor_dir();
 
         self.binary_installer.remove_binaries(initial);
+        // TODO(phase-c-promise): rewrite update_code().then(installBinaries + repo updates) as an await sequence.
         let promise = self.update_code(initial, target)?;
         let promise = match promise {
             Some(p) => p,
@@ -393,6 +377,7 @@ impl InstallerInterface for LibraryInstaller {
             .into());
         }
 
+        // TODO(phase-c-promise): rewrite remove_code().then(remove_binaries/remove_package/rmdir) as an await sequence.
         let promise = self.remove_code(package)?;
         let promise = match promise {
             Some(p) => p,
diff --git a/crates/shirabe/src/installer/metapackage_installer.rs b/crates/shirabe/src/installer/metapackage_installer.rs
index f6d6133..23d92f2 100644
--- a/crates/shirabe/src/installer/metapackage_installer.rs
+++ b/crates/shirabe/src/installer/metapackage_installer.rs
@@ -40,9 +40,7 @@ impl InstallerInterface for MetapackageInstaller {
         _package: &dyn PackageInterface,
         _prev_package: Option<&dyn PackageInterface>,
     ) -> Result<Option<PhpMixed>> {
-        Ok(Some(shirabe_external_packages::react::promise::resolve(
-            None,
-        )))
+        Ok(None)
     }
 
     async fn prepare(
@@ -51,9 +49,7 @@ impl InstallerInterface for MetapackageInstaller {
         _package: &dyn PackageInterface,
         _prev_package: Option<&dyn PackageInterface>,
     ) -> Result<Option<PhpMixed>> {
-        Ok(Some(shirabe_external_packages::react::promise::resolve(
-            None,
-        )))
+        Ok(None)
     }
 
     async fn cleanup(
@@ -62,9 +58,7 @@ impl InstallerInterface for MetapackageInstaller {
         _package: &dyn PackageInterface,
         _prev_package: Option<&dyn PackageInterface>,
     ) -> Result<Option<PhpMixed>> {
-        Ok(Some(shirabe_external_packages::react::promise::resolve(
-            None,
-        )))
+        Ok(None)
     }
 
     async fn install(
@@ -80,9 +74,7 @@ impl InstallerInterface for MetapackageInstaller {
 
         repo.add_package(package.clone_package_box());
 
-        Ok(Some(shirabe_external_packages::react::promise::resolve(
-            None,
-        )))
+        Ok(None)
     }
 
     async fn update(
@@ -108,9 +100,7 @@ impl InstallerInterface for MetapackageInstaller {
         repo.remove_package(initial);
         repo.add_package(target.clone_package_box());
 
-        Ok(Some(shirabe_external_packages::react::promise::resolve(
-            None,
-        )))
+        Ok(None)
     }
 
     async fn uninstall(
@@ -134,9 +124,7 @@ impl InstallerInterface for MetapackageInstaller {
 
         repo.remove_package(package);
 
-        Ok(Some(shirabe_external_packages::react::promise::resolve(
-            None,
-        )))
+        Ok(None)
     }
 
     fn get_install_path(&self, _package: &dyn PackageInterface) -> Option<String> {
diff --git a/crates/shirabe/src/installer/noop_installer.rs b/crates/shirabe/src/installer/noop_installer.rs
index 263caca..68e4ef8 100644
--- a/crates/shirabe/src/installer/noop_installer.rs
+++ b/crates/shirabe/src/installer/noop_installer.rs
@@ -26,9 +26,7 @@ impl InstallerInterface for NoopInstaller {
         _package: &dyn PackageInterface,
         _prev_package: Option<&dyn PackageInterface>,
     ) -> anyhow::Result<Option<PhpMixed>> {
-        Ok(Some(shirabe_external_packages::react::promise::resolve(
-            None,
-        )))
+        Ok(None)
     }
 
     async fn prepare(
@@ -37,9 +35,7 @@ impl InstallerInterface for NoopInstaller {
         _package: &dyn PackageInterface,
         _prev_package: Option<&dyn PackageInterface>,
     ) -> anyhow::Result<Option<PhpMixed>> {
-        Ok(Some(shirabe_external_packages::react::promise::resolve(
-            None,
-        )))
+        Ok(None)
     }
 
     async fn cleanup(
@@ -48,9 +44,7 @@ impl InstallerInterface for NoopInstaller {
         _package: &dyn PackageInterface,
         _prev_package: Option<&dyn PackageInterface>,
     ) -> anyhow::Result<Option<PhpMixed>> {
-        Ok(Some(shirabe_external_packages::react::promise::resolve(
-            None,
-        )))
+        Ok(None)
     }
 
     async fn install(
@@ -62,9 +56,7 @@ impl InstallerInterface for NoopInstaller {
             repo.add_package(package.clone_package_box());
         }
 
-        Ok(Some(shirabe_external_packages::react::promise::resolve(
-            None,
-        )))
+        Ok(None)
     }
 
     async fn update(
@@ -86,9 +78,7 @@ impl InstallerInterface for NoopInstaller {
             repo.add_package(target.clone_package_box());
         }
 
-        Ok(Some(shirabe_external_packages::react::promise::resolve(
-            None,
-        )))
+        Ok(None)
     }
 
     async fn uninstall(
@@ -105,9 +95,7 @@ impl InstallerInterface for NoopInstaller {
         }
         repo.remove_package(package);
 
-        Ok(Some(shirabe_external_packages::react::promise::resolve(
-            None,
-        )))
+        Ok(None)
     }
 
     fn get_install_path(&self, package: &dyn PackageInterface) -> Option<String> {
diff --git a/crates/shirabe/src/installer/plugin_installer.rs b/crates/shirabe/src/installer/plugin_installer.rs
index fd1fc99..4f9918e 100644
--- a/crates/shirabe/src/installer/plugin_installer.rs
+++ b/crates/shirabe/src/installer/plugin_installer.rs
@@ -96,7 +96,7 @@ impl InstallerInterface for PluginInstaller {
             let _ = plugin_optional;
         }
 
-        self.inner.prepare(r#type, package, prev_package)
+        self.inner.prepare(r#type, package, prev_package).await
     }
 
     async fn download(
@@ -116,7 +116,7 @@ impl InstallerInterface for PluginInstaller {
             }.into());
         }
 
-        self.inner.download(package, prev_package)
+        self.inner.download(package, prev_package).await
     }
 
     async fn install(
@@ -124,22 +124,13 @@ impl InstallerInterface for PluginInstaller {
         repo: &mut dyn InstalledRepositoryInterface,
         package: &dyn PackageInterface,
     ) -> Result<Option<PhpMixed>> {
-        let promise = self.inner.install(repo, package)?;
-        let promise = match promise {
-            Some(p) => p,
-            None => shirabe_external_packages::react::promise::resolve(None),
-        };
+        self.inner.install(repo, package).await?;
 
         // TODO(plugin): register package in plugin manager after install, rollback on failure
-        Ok(Some(promise.then(
-            Some(Box::new(move |_v| -> Option<PhpMixed> {
-                Platform::workaround_filesystem_issues();
-                // self.get_plugin_manager().register_package(package, true)?;
-                // On error: self.rollback_install(e, repo, package)?;
-                None
-            })),
-            None,
-        )))
+        Platform::workaround_filesystem_issues();
+        // self.get_plugin_manager().register_package(package, true)?;
+        // On error: self.rollback_install(e, repo, package)?;
+        Ok(None)
     }
 
     async fn update(
@@ -148,23 +139,14 @@ impl InstallerInterface for PluginInstaller {
         initial: &dyn PackageInterface,
         target: &dyn PackageInterface,
     ) -> Result<Option<PhpMixed>> {
-        let promise = self.inner.update(repo, initial, target)?;
-        let promise = match promise {
-            Some(p) => p,
-            None => shirabe_external_packages::react::promise::resolve(None),
-        };
+        self.inner.update(repo, initial, target).await?;
 
         // TODO(plugin): deactivate initial and register target in plugin manager after update, rollback on failure
-        Ok(Some(promise.then(
-            Some(Box::new(move |_v| -> Option<PhpMixed> {
-                Platform::workaround_filesystem_issues();
-                // self.get_plugin_manager().deactivate_package(initial);
-                // self.get_plugin_manager().register_package(target, true)?;
-                // On error: self.rollback_install(e, repo, target)?;
-                None
-            })),
-            None,
-        )))
+        Platform::workaround_filesystem_issues();
+        // self.get_plugin_manager().deactivate_package(initial);
+        // self.get_plugin_manager().register_package(target, true)?;
+        // On error: self.rollback_install(e, repo, target)?;
+        Ok(None)
     }
 
     async fn uninstall(
@@ -177,7 +159,7 @@ impl InstallerInterface for PluginInstaller {
             .borrow_mut()
             .uninstall_package(package);
 
-        self.inner.uninstall(repo, package)
+        self.inner.uninstall(repo, package).await
     }
 
     async fn cleanup(
@@ -186,7 +168,7 @@ impl InstallerInterface for PluginInstaller {
         package: &dyn PackageInterface,
         prev_package: Option<&dyn PackageInterface>,
     ) -> Result<Option<PhpMixed>> {
-        self.inner.cleanup(r#type, package, prev_package)
+        self.inner.cleanup(r#type, package, prev_package).await
     }
 
     fn get_install_path(&self, package: &dyn PackageInterface) -> Option<String> {
diff --git a/crates/shirabe/src/installer/project_installer.rs b/crates/shirabe/src/installer/project_installer.rs
index 1c50a16..034a07a 100644
--- a/crates/shirabe/src/installer/project_installer.rs
+++ b/crates/shirabe/src/installer/project_installer.rs
@@ -64,7 +64,7 @@ impl InstallerInterface for ProjectInstaller {
         self.download_manager
             .borrow()
             .download(package, install_path, prev_package)
-            .map(Some)
+            .await
     }
 
     async fn prepare(
@@ -76,7 +76,7 @@ impl InstallerInterface for ProjectInstaller {
         self.download_manager
             .borrow()
             .prepare(r#type, package, &self.install_path, prev_package)
-            .map(Some)
+            .await
     }
 
     async fn cleanup(
@@ -88,7 +88,7 @@ impl InstallerInterface for ProjectInstaller {
         self.download_manager
             .borrow()
             .cleanup(r#type, package, &self.install_path, prev_package)
-            .map(Some)
+            .await
     }
 
     async fn install(
@@ -96,11 +96,10 @@ impl InstallerInterface for ProjectInstaller {
         _repo: &mut dyn InstalledRepositoryInterface,
         package: &dyn PackageInterface,
     ) -> anyhow::Result<Option<PhpMixed>> {
-        Ok(Some(
-            self.download_manager
-                .borrow()
-                .install(package, &self.install_path)?,
-        ))
+        self.download_manager
+            .borrow()
+            .install(package, &self.install_path)
+            .await
     }
 
     async fn update(