core/tools+cli: split fetch into remote fetch and fetch_local

tests/test_tools/test_fetch_remote.py

@@ -0,0 +1,73 @@
+"""The remote ``fetch`` tool (DeepSeek's Fetch API, Markdown pages)."""
+
+from __future__ import annotations
+
+import pytest
+
+from plyngent.agent.tools import ToolTag
+from plyngent.lmproto.deepseek.webtools import FetchResponse
+from plyngent.tools.net.fetch_remote import FETCH_TOOL_NAME, build_fetch_tool
+
+
+class _Client:
+    """Stands in for DeepseekWebToolsClient.fetch."""
+
+    def __init__(self, *, page: FetchResponse | None = None, error: str | None = None) -> None:
+        self.page = page or FetchResponse(title="T", content="body")
+        self.error = error
+        self.urls: list[str] = []
+
+    async def fetch(self, url: str) -> FetchResponse:
+        self.urls.append(url)
+        if self.error is not None:
+            raise RuntimeError(self.error)
+        return self.page
+
+
+def _tool(client: _Client, *, max_chars: int = 32_000):
+    return build_fetch_tool(client, default_max_chars=max_chars)
+
+
+def test_definition_shape() -> None:
+    definition = _tool(_Client())
+    assert definition.name == FETCH_TOOL_NAME == "fetch"
+    assert definition.tags == ToolTag.LOCAL | ToolTag.READ_ONLY
+    properties = definition.parameters["properties"]
+    assert set(properties) == {"url", "offset", "max_chars"}
+    assert definition.parameters["required"] == ["url"]
+    assert "fetch_local" in definition.description
+
+
+@pytest.mark.asyncio
+async def test_handler_renders_title_url_and_content() -> None:
+    client = _Client(page=FetchResponse(title="  Example   article ", content="# Heading\n\nBody."))
+    result = await _tool(client).handler(url="https://example.com/article")
+
+    assert client.urls == ["https://example.com/article"]
+    assert result.splitlines() == [
+        "title=Example article",
+        "url=https://example.com/article",
+        "chars=16",
+        "truncated=false",
+        "--- content ---",
+        "# Heading",
+        "",
+        "Body.",
+    ]
+
+
+@pytest.mark.asyncio
+async def test_offset_and_truncation_keep_the_remainder_resumable() -> None:
+    client = _Client(page=FetchResponse(title="", content="0123456789"))
+    result = await _tool(client, max_chars=3).handler(url="https://example.com/", offset=5)
+
+    assert "title=(untitled)" in result
+    assert "--- content ---\n567" in result
+    assert "truncated=true" in result
+    assert "truncate_token=" in result
+
+
+@pytest.mark.asyncio
+async def test_handler_reports_a_client_error() -> None:
+    result = await _tool(_Client(error="HTTP 404: no usable content")).handler(url="https://example.com/x")
+    assert result == "error: fetch failed: HTTP 404: no usable content"