feat: add go pkg support (#259)

docs/usage.rst

@@ -946,6 +946,17 @@ Check `Visual Studio Code Marketplace <https://marketplace.visualstudio.com/vsco
 vsmarketplace
   The extension's Unique Identifier on marketplace.visualstudio.com/vscode, e.g. ``ritwickdey.LiveServer``.
 
+Check Go packages and modules
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+::
+
+  source = "go"
+
+Check `Go packages and modules <https://pkg.go.dev/>`_ for updates.
+
+go
+  The name of Go package or module, e.g. ``github.com/caddyserver/caddy/v2/cmd``.
+
 Combine others' results
 ~~~~~~~~~~~~~~~~~~~~~~~
 ::

nvchecker_source/go.py

@@ -0,0 +1,36 @@
+# MIT licensed
+# Copyright (c) 2024 bgme <i@bgme.me>.
+
+from lxml import html
+
+from nvchecker.api import (
+    VersionResult, Entry, AsyncCache, KeyManager,
+    session, GetVersionError, HTTPError
+)
+
+GO_PKG_URL = 'https://pkg.go.dev/{pkg}?tab=versions'
+
+
+async def get_version(
+        name: str, conf: Entry, *,
+        cache: AsyncCache, keymanager: KeyManager,
+        **kwargs,
+) -> VersionResult:
+    key = tuple(sorted(conf.items()))
+    return await cache.get(key, get_version_impl)
+
+
+async def get_version_impl(info) -> VersionResult:
+    conf = dict(info)
+    pkg_name = conf.get('go')
+
+    url = GO_PKG_URL.format(pkg=pkg_name)
+    res = await session.get(url)
+    doc = html.fromstring(res.body.decode())
+
+    elements = doc.xpath("//div[@class='Version-tag']/a/text()")
+    try:
+        version = elements[0]
+        return version
+    except IndexError:
+        raise GetVersionError("parse error", pkg_name=pkg_name)

tests/test_go.py

@@ -0,0 +1,36 @@
+# MIT licensed
+# Copyright (c) 2024 bgme <i@bgme.me>.
+
+import pytest
+
+from nvchecker.api import HTTPError
+
+lxml_available = True
+try:
+    import lxml
+except ImportError:
+    lxml_available = False
+
+pytestmark = [
+    pytest.mark.asyncio(scope="session"),
+    pytest.mark.needs_net,
+    pytest.mark.skipif(not lxml_available, reason="needs lxml")
+]
+
+
+async def test_go(get_version):
+    assert await get_version("one version", {
+        "source": "go",
+        "go": "github.com/caddyserver/replace-response",
+    }) == "v0.0.0-20231221003037-a85d4ddc11d6"
+
+    assert await get_version("multiple version", {
+        "source": "go",
+        "go": "github.com/corazawaf/coraza-caddy",
+    }) == "v1.2.2"
+
+    with pytest.raises(HTTPError):
+        await get_version("not found", {
+            "source": "go",
+            "go": "github.com/asdas/sadfasdf",
+        })