add context window monitor

Writes the current context window to logs/current_context_window (uses a symlink to a session ID).

This PR was unfortunately generated by a different LLM and did a ton of superficial reformating, it's actually a fairly small and benign change, but I don't want to roll back everything. Hope that's ok.

crates/g3-core/tests/test_todo_persistence.rs

@@ -1,20 +1,19 @@
-use g3_core::Agent;
 use g3_core::ui_writer::NullUiWriter;
+use g3_core::Agent;
 use serial_test::serial;
 use std::fs;
 use std::path::PathBuf;
 use tempfile::TempDir;
 
-
 /// Helper to create a test agent in a temporary directory
 async fn create_test_agent_in_dir(temp_dir: &TempDir) -> Agent<NullUiWriter> {
     // Change to temp directory
     std::env::set_current_dir(temp_dir.path()).unwrap();
-    
+
     // Create a minimal config
     let config = g3_config::Config::default();
     let ui_writer = NullUiWriter;
-    
+
     Agent::new(config, ui_writer).await.unwrap()
 }
 
@@ -29,10 +28,10 @@ async fn test_todo_write_creates_file() {
     let temp_dir = TempDir::new().unwrap();
     let mut agent = create_test_agent_in_dir(&temp_dir).await;
     let todo_path = get_todo_path(&temp_dir);
-    
+
     // Initially, todo.g3.md should not exist
     assert!(!todo_path.exists(), "todo.g3.md should not exist initially");
-    
+
     // Create a tool call to write TODO
     let tool_call = g3_core::ToolCall {
         tool: "todo_write".to_string(),
@@ -40,17 +39,21 @@ async fn test_todo_write_creates_file() {
             "content": "- [ ] Task 1\n- [ ] Task 2\n- [x] Task 3"
         }),
     };
-    
+
     // Execute the tool
     let result = agent.execute_tool(&tool_call).await.unwrap();
-    
+
     // Should report success
     assert!(result.contains("✅"), "Should report success: {}", result);
-    assert!(result.contains("todo.g3.md"), "Should mention todo.g3.md: {}", result);
-    
+    assert!(
+        result.contains("todo.g3.md"),
+        "Should mention todo.g3.md: {}",
+        result
+    );
+
     // File should now exist
     assert!(todo_path.exists(), "todo.g3.md should exist after write");
-    
+
     // File should contain the correct content
     let content = fs::read_to_string(&todo_path).unwrap();
     assert_eq!(content, "- [ ] Task 1\n- [ ] Task 2\n- [x] Task 3");
@@ -61,27 +64,39 @@ async fn test_todo_write_creates_file() {
 async fn test_todo_read_from_file() {
     let temp_dir = TempDir::new().unwrap();
     let todo_path = get_todo_path(&temp_dir);
-    
+
     // Pre-create a todo.g3.md file
     let test_content = "# My TODO\n\n- [ ] First task\n- [x] Completed task";
     fs::write(&todo_path, test_content).unwrap();
-    
+
     // Create agent (should load from file)
     let mut agent = create_test_agent_in_dir(&temp_dir).await;
-    
+
     // Create a tool call to read TODO
     let tool_call = g3_core::ToolCall {
         tool: "todo_read".to_string(),
         args: serde_json::json!({}),
     };
-    
+
     // Execute the tool
     let result = agent.execute_tool(&tool_call).await.unwrap();
-    
+
     // Should contain the TODO content
-    assert!(result.contains("📝 TODO list:"), "Should have TODO list header: {}", result);
-    assert!(result.contains("First task"), "Should contain first task: {}", result);
-    assert!(result.contains("Completed task"), "Should contain completed task: {}", result);
+    assert!(
+        result.contains("📝 TODO list:"),
+        "Should have TODO list header: {}",
+        result
+    );
+    assert!(
+        result.contains("First task"),
+        "Should contain first task: {}",
+        result
+    );
+    assert!(
+        result.contains("Completed task"),
+        "Should contain completed task: {}",
+        result
+    );
 }
 
 #[tokio::test]
@@ -89,16 +104,16 @@ async fn test_todo_read_from_file() {
 async fn test_todo_read_empty_file() {
     let temp_dir = TempDir::new().unwrap();
     let mut agent = create_test_agent_in_dir(&temp_dir).await;
-    
+
     // Create a tool call to read TODO (file doesn't exist)
     let tool_call = g3_core::ToolCall {
         tool: "todo_read".to_string(),
         args: serde_json::json!({}),
     };
-    
+
     // Execute the tool
     let result = agent.execute_tool(&tool_call).await.unwrap();
-    
+
     // Should report empty
     assert!(result.contains("empty"), "Should report empty: {}", result);
 }
@@ -108,7 +123,7 @@ async fn test_todo_read_empty_file() {
 async fn test_todo_persistence_across_agents() {
     let temp_dir = TempDir::new().unwrap();
     let todo_path = get_todo_path(&temp_dir);
-    
+
     // Agent 1: Write TODO
     {
         let mut agent = create_test_agent_in_dir(&temp_dir).await;
@@ -120,10 +135,13 @@ async fn test_todo_persistence_across_agents() {
         };
         agent.execute_tool(&tool_call).await.unwrap();
     }
-    
+
     // Verify file exists
-    assert!(todo_path.exists(), "todo.g3.md should persist after agent drops");
-    
+    assert!(
+        todo_path.exists(),
+        "todo.g3.md should persist after agent drops"
+    );
+
     // Agent 2: Read TODO (new agent instance)
     {
         let mut agent = create_test_agent_in_dir(&temp_dir).await;
@@ -132,10 +150,18 @@ async fn test_todo_persistence_across_agents() {
             args: serde_json::json!({}),
         };
         let result = agent.execute_tool(&tool_call).await.unwrap();
-        
+
         // Should read the persisted content
-        assert!(result.contains("Persistent task"), "Should read persisted task: {}", result);
-        assert!(result.contains("Done task"), "Should read done task: {}", result);
+        assert!(
+            result.contains("Persistent task"),
+            "Should read persisted task: {}",
+            result
+        );
+        assert!(
+            result.contains("Done task"),
+            "Should read done task: {}",
+            result
+        );
     }
 }
 
@@ -145,7 +171,7 @@ async fn test_todo_update_preserves_file() {
     let temp_dir = TempDir::new().unwrap();
     let mut agent = create_test_agent_in_dir(&temp_dir).await;
     let todo_path = get_todo_path(&temp_dir);
-    
+
     // Write initial TODO
     let write_call = g3_core::ToolCall {
         tool: "todo_write".to_string(),
@@ -154,7 +180,7 @@ async fn test_todo_update_preserves_file() {
         }),
     };
     agent.execute_tool(&write_call).await.unwrap();
-    
+
     // Update TODO
     let update_call = g3_core::ToolCall {
         tool: "todo_write".to_string(),
@@ -163,7 +189,7 @@ async fn test_todo_update_preserves_file() {
         }),
     };
     agent.execute_tool(&update_call).await.unwrap();
-    
+
     // Verify file has updated content
     let content = fs::read_to_string(&todo_path).unwrap();
     assert_eq!(content, "- [x] Task 1\n- [ ] Task 2\n- [ ] Task 3");
@@ -175,23 +201,30 @@ async fn test_todo_handles_large_content() {
     let temp_dir = TempDir::new().unwrap();
     let mut agent = create_test_agent_in_dir(&temp_dir).await;
     let todo_path = get_todo_path(&temp_dir);
-    
+
     // Create a large TODO (but under the 50k limit)
     let mut large_content = String::from("# Large TODO\n\n");
     for i in 0..100 {
-        large_content.push_str(&format!("- [ ] Task {} with a long description that exceeds normal line lengths\n", i));
+        large_content.push_str(&format!(
+            "- [ ] Task {} with a long description that exceeds normal line lengths\n",
+            i
+        ));
     }
-    
+
     let tool_call = g3_core::ToolCall {
         tool: "todo_write".to_string(),
         args: serde_json::json!({
             "content": large_content
         }),
     };
-    
+
     let result = agent.execute_tool(&tool_call).await.unwrap();
-    assert!(result.contains("✅"), "Should handle large content: {}", result);
-    
+    assert!(
+        result.contains("✅"),
+        "Should handle large content: {}",
+        result
+    );
+
     // Verify file contains all content
     let file_content = fs::read_to_string(&todo_path).unwrap();
     assert_eq!(file_content, large_content);
@@ -203,22 +236,30 @@ async fn test_todo_handles_large_content() {
 async fn test_todo_respects_size_limit() {
     let temp_dir = TempDir::new().unwrap();
     let mut agent = create_test_agent_in_dir(&temp_dir).await;
-    
+
     // Create content that exceeds the default 50k limit
     let huge_content = "x".repeat(60_000);
-    
+
     let tool_call = g3_core::ToolCall {
         tool: "todo_write".to_string(),
         args: serde_json::json!({
             "content": huge_content
         }),
     };
-    
+
     let result = agent.execute_tool(&tool_call).await.unwrap();
-    
+
     // Should reject content that's too large
-    assert!(result.contains("❌"), "Should reject oversized content: {}", result);
-    assert!(result.contains("too large"), "Should mention size limit: {}", result);
+    assert!(
+        result.contains("❌"),
+        "Should reject oversized content: {}",
+        result
+    );
+    assert!(
+        result.contains("too large"),
+        "Should mention size limit: {}",
+        result
+    );
 }
 
 #[tokio::test]
@@ -226,22 +267,26 @@ async fn test_todo_respects_size_limit() {
 async fn test_todo_agent_initialization_loads_file() {
     let temp_dir = TempDir::new().unwrap();
     let todo_path = get_todo_path(&temp_dir);
-    
+
     // Pre-create todo.g3.md before agent initialization
     let initial_content = "- [ ] Pre-existing task";
     fs::write(&todo_path, initial_content).unwrap();
-    
+
     // Create agent - should load the file during initialization
     let mut agent = create_test_agent_in_dir(&temp_dir).await;
-    
+
     // Read TODO - should return the pre-existing content
     let tool_call = g3_core::ToolCall {
         tool: "todo_read".to_string(),
         args: serde_json::json!({}),
     };
-    
+
     let result = agent.execute_tool(&tool_call).await.unwrap();
-    assert!(result.contains("Pre-existing task"), "Should load file on init: {}", result);
+    assert!(
+        result.contains("Pre-existing task"),
+        "Should load file on init: {}",
+        result
+    );
 }
 
 #[tokio::test]
@@ -250,33 +295,41 @@ async fn test_todo_handles_unicode_content() {
     let temp_dir = TempDir::new().unwrap();
     let mut agent = create_test_agent_in_dir(&temp_dir).await;
     let todo_path = get_todo_path(&temp_dir);
-    
+
     // Create TODO with unicode characters
     let unicode_content = "- [ ] 日本語タスク\n- [ ] Émoji task 🚀\n- [x] Ελληνικά task";
-    
+
     let tool_call = g3_core::ToolCall {
         tool: "todo_write".to_string(),
         args: serde_json::json!({
             "content": unicode_content
         }),
     };
-    
+
     agent.execute_tool(&tool_call).await.unwrap();
-    
+
     // Verify file preserves unicode
     let file_content = fs::read_to_string(&todo_path).unwrap();
     assert_eq!(file_content, unicode_content);
-    
+
     // Verify reading back works
     let read_call = g3_core::ToolCall {
         tool: "todo_read".to_string(),
         args: serde_json::json!({}),
     };
-    
+
     let result = agent.execute_tool(&read_call).await.unwrap();
-    assert!(result.contains("日本語"), "Should preserve Japanese: {}", result);
+    assert!(
+        result.contains("日本語"),
+        "Should preserve Japanese: {}",
+        result
+    );
     assert!(result.contains("🚀"), "Should preserve emoji: {}", result);
-    assert!(result.contains("Ελληνικά"), "Should preserve Greek: {}", result);
+    assert!(
+        result.contains("Ελληνικά"),
+        "Should preserve Greek: {}",
+        result
+    );
 }
 
 #[tokio::test]
@@ -285,7 +338,7 @@ async fn test_todo_empty_content_creates_empty_file() {
     let temp_dir = TempDir::new().unwrap();
     let mut agent = create_test_agent_in_dir(&temp_dir).await;
     let todo_path = get_todo_path(&temp_dir);
-    
+
     // Write empty TODO
     let tool_call = g3_core::ToolCall {
         tool: "todo_write".to_string(),
@@ -293,9 +346,9 @@ async fn test_todo_empty_content_creates_empty_file() {
             "content": ""
         }),
     };
-    
+
     agent.execute_tool(&tool_call).await.unwrap();
-    
+
     // File should exist but be empty
     assert!(todo_path.exists(), "Empty todo.g3.md should create file");
     let content = fs::read_to_string(&todo_path).unwrap();
@@ -307,7 +360,7 @@ async fn test_todo_empty_content_creates_empty_file() {
 async fn test_todo_whitespace_only_content() {
     let temp_dir = TempDir::new().unwrap();
     let mut agent = create_test_agent_in_dir(&temp_dir).await;
-    
+
     // Write whitespace-only TODO
     let tool_call = g3_core::ToolCall {
         tool: "todo_write".to_string(),
@@ -315,17 +368,21 @@ async fn test_todo_whitespace_only_content() {
             "content": "   \n\n  \t  \n"
         }),
     };
-    
+
     agent.execute_tool(&tool_call).await.unwrap();
-    
+
     // Read it back
     let read_call = g3_core::ToolCall {
         tool: "todo_read".to_string(),
         args: serde_json::json!({}),
     };
-    
+
     let result = agent.execute_tool(&read_call).await.unwrap();
-    
+
     // Should report as empty (whitespace is trimmed)
-    assert!(result.contains("empty"), "Whitespace-only should be empty: {}", result);
+    assert!(
+        result.contains("empty"),
+        "Whitespace-only should be empty: {}",
+        result
+    );
 }