Add a baseline test for resume initial messages (#5466)

codex-rs/core/tests/common/test_codex.rs

@@ -6,7 +6,6 @@ use codex_core::CodexAuth;
 use codex_core::CodexConversation;
 use codex_core::ConversationManager;
 use codex_core::ModelProviderInfo;
-use codex_core::NewConversation;
 use codex_core::built_in_model_providers;
 use codex_core::config::Config;
 use codex_core::protocol::SessionConfiguredEvent;
@@ -30,14 +29,59 @@ impl TestCodexBuilder {
     }
 
     pub async fn build(&mut self, server: &wiremock::MockServer) -> anyhow::Result<TestCodex> {
-        // Build config pointing to the mock server and spawn Codex.
+        let home = Arc::new(TempDir::new()?);
+        self.build_with_home(server, home, None).await
+    }
+
+    pub async fn resume(
+        &mut self,
+        server: &wiremock::MockServer,
+        home: Arc<TempDir>,
+        rollout_path: PathBuf,
+    ) -> anyhow::Result<TestCodex> {
+        self.build_with_home(server, home, Some(rollout_path)).await
+    }
+
+    async fn build_with_home(
+        &mut self,
+        server: &wiremock::MockServer,
+        home: Arc<TempDir>,
+        resume_from: Option<PathBuf>,
+    ) -> anyhow::Result<TestCodex> {
+        let (config, cwd) = self.prepare_config(server, &home).await?;
+        let conversation_manager = ConversationManager::with_auth(CodexAuth::from_api_key("dummy"));
+
+        let new_conversation = match resume_from {
+            Some(path) => {
+                let auth_manager = codex_core::AuthManager::from_auth_for_testing(
+                    CodexAuth::from_api_key("dummy"),
+                );
+                conversation_manager
+                    .resume_conversation_from_rollout(config, path, auth_manager)
+                    .await?
+            }
+            None => conversation_manager.new_conversation(config).await?,
+        };
+
+        Ok(TestCodex {
+            home,
+            cwd,
+            codex: new_conversation.conversation,
+            session_configured: new_conversation.session_configured,
+        })
+    }
+
+    async fn prepare_config(
+        &mut self,
+        server: &wiremock::MockServer,
+        home: &TempDir,
+    ) -> anyhow::Result<(Config, Arc<TempDir>)> {
         let model_provider = ModelProviderInfo {
             base_url: Some(format!("{}/v1", server.uri())),
             ..built_in_model_providers()["openai"].clone()
         };
-        let home = TempDir::new()?;
-        let cwd = TempDir::new()?;
-        let mut config = load_default_config_for_test(&home);
+        let cwd = Arc::new(TempDir::new()?);
+        let mut config = load_default_config_for_test(home);
         config.cwd = cwd.path().to_path_buf();
         config.model_provider = model_provider;
         config.codex_linux_sandbox_exe = Some(PathBuf::from(
@@ -48,29 +92,17 @@ impl TestCodexBuilder {
 
         let mut mutators = vec![];
         swap(&mut self.config_mutators, &mut mutators);
-
         for mutator in mutators {
-            mutator(&mut config)
+            mutator(&mut config);
         }
-        let conversation_manager = ConversationManager::with_auth(CodexAuth::from_api_key("dummy"));
-        let NewConversation {
-            conversation,
-            session_configured,
-            ..
-        } = conversation_manager.new_conversation(config).await?;
 
-        Ok(TestCodex {
-            home,
-            cwd,
-            codex: conversation,
-            session_configured,
-        })
+        Ok((config, cwd))
     }
 }
 
 pub struct TestCodex {
-    pub home: TempDir,
-    pub cwd: TempDir,
+    pub home: Arc<TempDir>,
+    pub cwd: Arc<TempDir>,
     pub codex: Arc<CodexConversation>,
     pub session_configured: SessionConfiguredEvent,
 }