breakdown folder tree for epic R01

tests/unit/test_fakes.py

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+"""Unit tests for FakeProvider and FakeToolExecutor test doubles."""
+from __future__ import annotations
+
+import pytest
+
+from providers.base import ProviderError
+from tests.fakes.fake_provider import FakeProvider
+from tests.fakes.fake_tool_executor import FakeToolExecutor
+
+
+def test_fake_provider_text_streaming() -> None:
+    """Verify that FakeProvider streams text chunks to on_text callback."""
+    provider = FakeProvider()
+    provider.queue_response(content="Hello world", chunks=["Hello ", "world"])
+
+    streamed: list[str] = []
+    response = provider.chat(
+        messages=[{"role": "user", "content": "Hi"}],
+        on_text=lambda piece: streamed.append(piece),
+    )
+
+    assert response["role"] == "assistant"
+    assert response["content"] == "Hello world"
+    assert "".join(streamed) == "Hello world"
+    assert provider.call_count == 1
+
+
+def test_fake_provider_tool_calls_and_reasoning() -> None:
+    """Verify reasoning streaming and tool_calls payload emission."""
+    provider = FakeProvider()
+    tool_call = {
+        "id": "call_123",
+        "name": "save_file",
+        "arguments": {"filename": "out.txt", "content": "data"},
+    }
+    provider.queue_response(
+        content="Creating file",
+        tool_calls=[tool_call],
+        reasoning="User wants output in a file",
+    )
+
+    reasoning_chunks: list[str] = []
+    response = provider.chat(
+        messages=[{"role": "user", "content": "Save to out.txt"}],
+        on_reasoning=lambda piece: reasoning_chunks.append(piece),
+    )
+
+    assert response["content"] == "Creating file"
+    assert response["tool_calls"] == [tool_call]
+    assert reasoning_chunks == ["User wants output in a file"]
+
+
+def test_fake_provider_error_injection() -> None:
+    """Verify that queued exceptions are raised on demand."""
+    provider = FakeProvider()
+    provider.queue_error(ProviderError("Rate limit exceeded (429)"))
+
+    with pytest.raises(ProviderError, match="Rate limit exceeded"):
+        provider.chat(messages=[{"role": "user", "content": "Hi"}])
+
+
+def test_fake_provider_cancellation() -> None:
+    """Verify that cancellation stops execution immediately."""
+    provider = FakeProvider()
+    provider.queue_response(content="Long reply", chunks=["Part 1", "Part 2"])
+
+    is_cancelled = False
+
+    def cancel_fn() -> bool:
+        return is_cancelled
+
+    is_cancelled = True
+    with pytest.raises(ProviderError, match="aborted by user cancel"):
+        provider.chat(
+            messages=[{"role": "user", "content": "Hi"}],
+            cancel=cancel_fn,
+        )
+
+
+def test_fake_tool_executor() -> None:
+    """Verify that FakeToolExecutor records calls and returns expected mock outputs."""
+    executor = FakeToolExecutor()
+    executor.set_mock_response("read_file", {"ok": True, "content": "file contents"})
+    executor.register_handler("calc", lambda args: {"ok": True, "result": args.get("a", 0) + args.get("b", 0)})
+
+    res1 = executor.execute("read_file", {"path": "test.txt"})
+    assert res1["ok"] is True
+    assert res1["content"] == "file contents"
+
+    res2 = executor.execute("calc", {"a": 5, "b": 10})
+    assert res2["result"] == 15
+
+    assert len(executor.call_log) == 2
+    assert executor.get_calls_for("calc")[0]["args"] == {"a": 5, "b": 10}