docs: add task for agent prompt generation

tests/test_prompt.py

@@ -0,0 +1,131 @@
+from pathlib import Path
+
+import pytest
+
+from rdb_discovery.tasks import generate_agent_prompt, get_next_task
+
+
+def test_generate_agent_prompt_includes_task_info(tmp_path: Path) -> None:
+    (tmp_path / "TASKS.md").write_text(
+        "# TASKS\n\n"
+        "## TASK-001 — First\nStatus: Done\n\n"
+        "Goal: First goal.\n\n"
+        "Acceptance Criteria:\n"
+        "- a\n\n"
+        "## TASK-002 — Second\nStatus: Todo\n\n"
+        "Goal: Second goal.\n\n"
+        "Acceptance Criteria:\n"
+        "- b\n"
+        "- c\n",
+        encoding="utf-8",
+    )
+
+    prompt = generate_agent_prompt(tmp_path)
+
+    assert "TASK-002" in prompt
+    assert "Second" in prompt
+    assert "Todo" in prompt
+    assert "Second goal." in prompt
+
+
+def test_generate_agent_prompt_includes_acceptance_criteria(tmp_path: Path) -> None:
+    (tmp_path / "TASKS.md").write_text(
+        "# TASKS\n\n"
+        "## TASK-001 — First\nStatus: Done\n\n"
+        "Goal: x.\n\n"
+        "Acceptance Criteria:\n"
+        "- alpha\n\n"
+        "## TASK-002 — Second\nStatus: Todo\n\n"
+        "Goal: y.\n\n"
+        "Acceptance Criteria:\n"
+        "- bravo\n",
+        encoding="utf-8",
+    )
+
+    prompt = generate_agent_prompt(tmp_path)
+
+    assert "- alpha" not in prompt
+    assert "- bravo" in prompt
+
+
+def test_generate_agent_prompt_includes_read_instructions(tmp_path: Path) -> None:
+    (tmp_path / "TASKS.md").write_text(
+        "# TASKS\n\n"
+        "## TASK-001 — First\nStatus: Done\n\n"
+        "Goal: x.\n\n"
+        "## TASK-002 — Second\nStatus: Todo\n\n"
+        "Goal: y.\n",
+        encoding="utf-8",
+    )
+
+    prompt = generate_agent_prompt(tmp_path)
+
+    assert "README.md" in prompt
+    assert "TASKS.md" in prompt
+    assert "PROJECT_STATE.md" in prompt
+    assert "AGENT_HANDOFF.md" in prompt
+    assert "context/agent-guidelines.md" in prompt
+
+
+def test_generate_agent_prompt_includes_one_task_constraint(tmp_path: Path) -> None:
+    (tmp_path / "TASKS.md").write_text(
+        "# TASKS\n\n"
+        "## TASK-001 — First\nStatus: Done\n\n"
+        "Goal: x.\n\n"
+        "## TASK-002 — Second\nStatus: Todo\n\n"
+        "Goal: y.\n",
+        encoding="utf-8",
+    )
+
+    prompt = generate_agent_prompt(tmp_path)
+
+    assert "ONE task only" in prompt or "one task only" in prompt
+
+
+def test_generate_agent_prompt_includes_validation(tmp_path: Path) -> None:
+    (tmp_path / "TASKS.md").write_text(
+        "# TASKS\n\n"
+        "## TASK-001 — First\nStatus: Done\n\n"
+        "Goal: x.\n\n"
+        "## TASK-002 — Second\nStatus: Todo\n\n"
+        "Goal: y.\n",
+        encoding="utf-8",
+    )
+
+    prompt = generate_agent_prompt(tmp_path)
+
+    assert "Validation" in prompt
+    assert "pytest" in prompt
+
+
+def test_generate_agent_prompt_includes_reporting(tmp_path: Path) -> None:
+    (tmp_path / "TASKS.md").write_text(
+        "# TASKS\n\n"
+        "## TASK-001 — First\nStatus: Done\n\n"
+        "Goal: x.\n\n"
+        "## TASK-002 — Second\nStatus: Todo\n\n"
+        "Goal: y.\n",
+        encoding="utf-8",
+    )
+
+    prompt = generate_agent_prompt(tmp_path)
+
+    assert "Reporting" in prompt
+
+
+def test_generate_agent_prompt_no_todo_task(tmp_path: Path) -> None:
+    (tmp_path / "TASKS.md").write_text(
+        "# TASKS\n\n"
+        "## TASK-001 — First\nStatus: Done\n\n",
+        encoding="utf-8",
+    )
+
+    prompt = generate_agent_prompt(tmp_path)
+
+    assert prompt == "No Todo task found."
+
+
+def test_generate_agent_prompt_no_tasks_file(tmp_path: Path) -> None:
+    prompt = generate_agent_prompt(tmp_path)
+
+    assert prompt == "No Todo task found."