refactor(installed-repository): make add_repository infallible with assert

The repository type check was an internal invariant, not a recoverable
error condition. Replace the Result-returning validation with an
assert!, matching Composer's design where add_repository throws only on
a programming error, and drop the now-unneeded error handling at call
sites.

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

3 files changed, 17 insertions, 29 deletions

diff --git a/crates/shirabe/src/command/base_dependency_command.rs b/crates/shirabe/src/command/base_dependency_command.rs
index 4a5b854..a9ed7cd 100644
--- a/crates/shirabe/src/command/base_dependency_command.rs
+++ b/crates/shirabe/src/command/base_dependency_command.rs
@@ -166,13 +166,11 @@ pub trait BaseDependencyCommand: BaseCommand {
                 &needle,
                 FindPackageConstraint::String(text_constraint.clone()),
             )? {
-                installed_repo.add_repository(
-                    crate::repository::RepositoryInterfaceHandle::new(
-                        InstalledArrayRepository::new_with_packages(vec![
-                            crate::package::PackageInterfaceHandle::dup(&r#match),
-                        ])?,
-                    ),
-                )?;
+                installed_repo.add_repository(crate::repository::RepositoryInterfaceHandle::new(
+                    InstalledArrayRepository::new_with_packages(vec![
+                        crate::package::PackageInterfaceHandle::dup(&r#match),
+                    ])?,
+                ));
             } else if PlatformRepository::is_platform_package(&needle) {
                 let parser = VersionParser::new();
                 let platform_constraint = parser.parse_constraints(&text_constraint)?;
@@ -189,7 +187,7 @@ pub trait BaseDependencyCommand: BaseCommand {
                                     .into(),
                             ])?,
                         ),
-                    )?;
+                    );
                 }
             } else {
                 self.get_io().write_error(&format!(
diff --git a/crates/shirabe/src/command/show_command.rs b/crates/shirabe/src/command/show_command.rs
index e14ab15..859ba97 100644
--- a/crates/shirabe/src/command/show_command.rs
+++ b/crates/shirabe/src/command/show_command.rs
@@ -270,7 +270,7 @@ impl ShowCommand {
                         .get_repository_manager()
                         .borrow()
                         .get_local_repository(),
-                )?;
+                );
                 installed_repo = RepositoryInterfaceHandle::new(ir);
             } else {
                 let default_repos =
diff --git a/crates/shirabe/src/repository/installed_repository.rs b/crates/shirabe/src/repository/installed_repository.rs
index b8321d6..2bd6fc6 100644
--- a/crates/shirabe/src/repository/installed_repository.rs
+++ b/crates/shirabe/src/repository/installed_repository.rs
@@ -43,9 +43,7 @@ impl InstalledRepository {
             inner: CompositeRepository::new(vec![]),
         };
         for repo in repositories {
-            // TODO(phase-b): add_repository validates the inner repo type and may return Err;
-            // ignoring the error during Phase B since callers do not handle it.
-            let _ = this.add_repository(repo);
+            this.add_repository(repo);
         }
         this
     }
@@ -366,24 +364,16 @@ impl InstalledRepository {
         Ok(results)
     }
 
-    pub fn add_repository(&mut self, repository: RepositoryInterfaceHandle) -> anyhow::Result<()> {
-        if repository.is::<LockArrayRepository>()
-            || repository.is::<RootPackageRepository>()
-            || repository.is::<PlatformRepository>()
-        {
-            self.inner.add_repository(repository);
-            return Ok(());
-        }
+    pub fn add_repository(&mut self, repository: RepositoryInterfaceHandle) {
+        // TODO: type guard?
+        assert!(
+            repository.is::<LockArrayRepository>()
+                || repository.is::<RootPackageRepository>()
+                || repository.is::<PlatformRepository>(),
+            "An InstalledRepository can contain a repository of type: LockArrayRepository, RootPackageRepository or PlatformRepository"
+        );
 
-        let type_name = std::any::type_name_of_val(&*repository.borrow()).to_string();
-        let repo_name = repository.get_repo_name();
-        Err(anyhow::anyhow!(LogicException {
-            message: format!(
-                "An InstalledRepository can not contain a repository of type {} ({})",
-                type_name, repo_name,
-            ),
-            code: 0,
-        }))
+        self.inner.add_repository(repository);
     }
 }