feat: add render functions and DisplayAdapter for TUI display

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

app/utils/display.py

@@ -1,7 +1,18 @@
-"""Rich terminal display helpers for SneakyCode."""
+"""Rich terminal display helpers for SneakyCode.
+
+Provides two interfaces:
+- render_* functions: return Rich renderables (for use in Textual RichLog)
+- DisplayAdapter: wraps a RichLog widget and provides write_* convenience methods
+- print_* functions: legacy console.print wrappers (for non-TUI fallback)
+"""
+
+from __future__ import annotations
+
+from typing import TYPE_CHECKING, Protocol
 
 from rich.panel import Panel
 from rich.table import Table
+from rich.text import Text
 from rich.theme import Theme
 
 from app.models.message import Message
@@ -23,6 +34,166 @@ SNEAKYCODE_THEME = Theme(
 console.push_theme(SNEAKYCODE_THEME)
 
 
+if TYPE_CHECKING:
+    from rich.console import RenderableType
+
+
+# ---------------------------------------------------------------------------
+# Render functions — return Rich renderables
+# ---------------------------------------------------------------------------
+
+
+def render_user_message(content: str) -> Panel:
+    """Render a user message as a styled panel."""
+    return Panel(content, title="You", border_style="cyan", expand=False)
+
+
+def render_assistant_message(content: str) -> Panel:
+    """Render an assistant message as a styled panel."""
+    return Panel(content, title="Assistant", border_style="green", expand=True)
+
+
+def render_tool_call(name: str, args: str) -> Text:
+    """Render a compact tool call line."""
+    truncated_args = args[:80] + "..." if len(args) > 80 else args
+    text = Text()
+    text.append("  ")
+    text.append(name, style="magenta")
+    text.append(f" {truncated_args}", style="dim")
+    return text
+
+
+def render_tool_result(name: str, output: str, is_error: bool = False) -> Text:
+    """Render a compact tool result line."""
+    text = Text()
+    text.append("  ")
+    if is_error:
+        truncated = output[:200] + "..." if len(output) > 200 else output
+        text.append(f"{name}: {truncated}", style="bold red")
+    else:
+        lines = output.count("\n") + 1 if output else 0
+        chars = len(output)
+        text.append(f"{name} — {lines} lines, {chars} chars", style="dim")
+    return text
+
+
+def render_iteration_header(iteration: int, max_iterations: int) -> Text:
+    """Render the current agent loop iteration."""
+    return Text(f"── iteration {iteration}/{max_iterations} ──", style="dim")
+
+
+def render_token_usage(usage_tokens: int, budget: int) -> Text:
+    """Render token usage as styled text."""
+    return Text(f"Tokens: ~{usage_tokens:,} / {budget:,}", style="dim")
+
+
+def render_warning(message: str) -> Text:
+    """Render a warning message."""
+    return Text(f"⚠ {message}", style="yellow")
+
+
+def render_error(message: str) -> Text:
+    """Render an error message."""
+    return Text(f"✗ {message}", style="bold red")
+
+
+def render_success(message: str) -> Text:
+    """Render a success message."""
+    return Text(f"✓ {message}", style="bold green")
+
+
+def render_info(message: str) -> Text:
+    """Render an info message."""
+    return Text(message, style="cyan")
+
+
+def render_history(messages: list[Message]) -> Table | Text:
+    """Render conversation history as a Rich table."""
+    if not messages:
+        return Text("No messages in history.", style="dim")
+
+    table = Table(title="Conversation History")
+    table.add_column("#", style="dim", width=4)
+    table.add_column("Role", width=10)
+    table.add_column("Content")
+
+    role_styles = {
+        "user": "cyan",
+        "assistant": "green",
+        "system": "yellow",
+        "tool": "magenta",
+    }
+
+    for i, msg in enumerate(messages, 1):
+        style = role_styles.get(msg.role, "white")
+        content = msg.content or "(no content)"
+        if len(content) > 120:
+            content = content[:117] + "..."
+        table.add_row(str(i), f"[{style}]{msg.role}[/{style}]", content)
+
+    return table
+
+
+# ---------------------------------------------------------------------------
+# DisplayAdapter — wraps a writable target (RichLog or similar)
+# ---------------------------------------------------------------------------
+
+
+class WritableLog(Protocol):
+    """Protocol for anything that accepts Rich renderables via write()."""
+
+    def write(self, content: "RenderableType") -> None: ...
+
+
+class DisplayAdapter:
+    """Bridges agent loop display calls to a RichLog widget.
+
+    All write_* methods call the corresponding render_* function and
+    write the result to the target log.
+    """
+
+    def __init__(self, log: WritableLog) -> None:
+        self._log = log
+
+    def write_user_message(self, content: str) -> None:
+        self._log.write(render_user_message(content))
+
+    def write_assistant_message(self, content: str) -> None:
+        self._log.write(render_assistant_message(content))
+
+    def write_tool_call(self, name: str, args: str) -> None:
+        self._log.write(render_tool_call(name, args))
+
+    def write_tool_result(self, name: str, output: str, is_error: bool = False) -> None:
+        self._log.write(render_tool_result(name, output, is_error))
+
+    def write_iteration_header(self, iteration: int, max_iterations: int) -> None:
+        self._log.write(render_iteration_header(iteration, max_iterations))
+
+    def write_token_usage(self, usage_tokens: int, budget: int) -> None:
+        self._log.write(render_token_usage(usage_tokens, budget))
+
+    def write_warning(self, message: str) -> None:
+        self._log.write(render_warning(message))
+
+    def write_error(self, message: str) -> None:
+        self._log.write(render_error(message))
+
+    def write_success(self, message: str) -> None:
+        self._log.write(render_success(message))
+
+    def write_info(self, message: str) -> None:
+        self._log.write(render_info(message))
+
+    def write_history(self, messages: list[Message]) -> None:
+        self._log.write(render_history(messages))
+
+
+# ---------------------------------------------------------------------------
+# Legacy print functions — for non-TUI fallback and pre-TUI startup
+# ---------------------------------------------------------------------------
+
+
 def print_banner() -> None:
     """Print the SneakyCode startup banner."""
     console.print(
@@ -61,25 +232,17 @@ def print_assistant_message(content: str) -> None:
 
 
 def print_tool_call(name: str, args: str) -> None:
-    """Print a compact tool call line — tool name + truncated key args."""
+    """Print a compact tool call line."""
     truncated_args = args[:80] + "..." if len(args) > 80 else args
     console.print(f"  [tool]{name}[/tool] [dim]{truncated_args}[/dim]")
 
 
 def print_tool_result(name: str, output: str, is_error: bool = False) -> None:
-    """Print a compact tool result — status line only for success, detail for errors.
-
-    Args:
-        name: Tool name.
-        output: Tool output or error message.
-        is_error: Whether this is an error result.
-    """
+    """Print a compact tool result."""
     if is_error:
-        # Errors are shown prominently so the user knows something went wrong
         truncated = output[:200] + "..." if len(output) > 200 else output
         console.print(f"  [error]{name}: {truncated}[/error]")
     else:
-        # Success: just show a compact byte/line summary
         lines = output.count("\n") + 1 if output else 0
         chars = len(output)
         console.print(f"  [dim]{name} — {lines} lines, {chars} chars[/dim]")
@@ -96,33 +259,5 @@ def print_token_usage(usage_tokens: int, budget: int) -> None:
 
 
 def print_history(messages: list[Message]) -> None:
-    """Print conversation history as a Rich table.
-
-    Args:
-        messages: List of conversation messages to display.
-    """
-    if not messages:
-        console.print("[dim]No messages in history.[/dim]")
-        return
-
-    table = Table(title="Conversation History")
-    table.add_column("#", style="dim", width=4)
-    table.add_column("Role", width=10)
-    table.add_column("Content")
-
-    role_styles = {
-        "user": "cyan",
-        "assistant": "green",
-        "system": "yellow",
-        "tool": "magenta",
-    }
-
-    for i, msg in enumerate(messages, 1):
-        style = role_styles.get(msg.role, "white")
-        content = msg.content or "[dim](no content)[/dim]"
-        # Truncate long content for display
-        if len(content) > 120:
-            content = content[:117] + "..."
-        table.add_row(str(i), f"[{style}]{msg.role}[/{style}]", content)
-
-    console.print(table)
+    """Print conversation history as a Rich table."""
+    console.print(render_history(messages))

tests/unit/test_display.py

@@ -0,0 +1,87 @@
+"""Tests for display render functions and DisplayAdapter."""
+
+from unittest.mock import MagicMock
+
+from rich.panel import Panel
+from rich.table import Table
+from rich.text import Text
+
+from app.models.message import Message
+from app.utils.display import (
+    DisplayAdapter,
+    render_assistant_message,
+    render_error,
+    render_iteration_header,
+    render_tool_call,
+    render_tool_result,
+    render_token_usage,
+    render_user_message,
+    render_warning,
+)
+
+
+class TestRenderFunctions:
+    def test_render_user_message_returns_panel(self) -> None:
+        result = render_user_message("hello")
+        assert isinstance(result, Panel)
+        assert result.title == "You"
+
+    def test_render_assistant_message_returns_panel(self) -> None:
+        result = render_assistant_message("response")
+        assert isinstance(result, Panel)
+        assert result.title == "Assistant"
+
+    def test_render_tool_call_returns_text(self) -> None:
+        result = render_tool_call("read_file", '{"path": "foo.py"}')
+        assert isinstance(result, Text)
+        assert "read_file" in result.plain
+
+    def test_render_tool_result_success(self) -> None:
+        result = render_tool_result("read_file", "file contents here", is_error=False)
+        assert isinstance(result, Text)
+        assert "read_file" in result.plain
+
+    def test_render_tool_result_error(self) -> None:
+        result = render_tool_result("read_file", "not found", is_error=True)
+        assert isinstance(result, Text)
+        assert "read_file" in result.plain
+
+    def test_render_iteration_header(self) -> None:
+        result = render_iteration_header(3, 25)
+        assert isinstance(result, Text)
+        assert "3/25" in result.plain
+
+    def test_render_token_usage(self) -> None:
+        result = render_token_usage(1500, 32000)
+        assert isinstance(result, Text)
+        assert "1,500" in result.plain
+
+    def test_render_warning(self) -> None:
+        result = render_warning("something happened")
+        assert isinstance(result, Text)
+
+    def test_render_error(self) -> None:
+        result = render_error("bad thing")
+        assert isinstance(result, Text)
+
+
+class TestDisplayAdapter:
+    def test_write_user_message(self) -> None:
+        mock_log = MagicMock()
+        adapter = DisplayAdapter(mock_log)
+        adapter.write_user_message("hello")
+        mock_log.write.assert_called_once()
+        arg = mock_log.write.call_args[0][0]
+        assert isinstance(arg, Panel)
+
+    def test_write_tool_call(self) -> None:
+        mock_log = MagicMock()
+        adapter = DisplayAdapter(mock_log)
+        adapter.write_tool_call("read_file", '{"path": "x"}')
+        mock_log.write.assert_called_once()
+
+    def test_write_warning(self) -> None:
+        mock_log = MagicMock()
+        adapter = DisplayAdapter(mock_log)
+        adapter.write_warning("oops")
+        mock_log.write.assert_called_once()