GitHubIssuesLoader Custom API URL Support (#11378)

- **Description:** Adds support for custom API URL in the
GitHubIssuesLoader. This allows it to be used with Github enterprise
instances.

libs/langchain/langchain/document_loaders/github.py

@@ -17,6 +17,8 @@ class BaseGitHubLoader(BaseLoader, BaseModel, ABC):
     """Name of repository"""
     access_token: str
     """Personal access token - see https://github.com/settings/tokens?type=beta"""
+    github_api_url: str = "https://api.github.com"
+    """URL of GitHub API"""
 
     @root_validator(pre=True)
     def validate_environment(cls, values: Dict) -> Dict:
@@ -183,4 +185,4 @@ class GitHubIssuesLoader(BaseGitHubLoader):
     @property
     def url(self) -> str:
         """Create URL for GitHub API."""
-        return f"https://api.github.com/repos/{self.repo}/issues?{self.query_params}"
+        return f"{self.github_api_url}/repos/{self.repo}/issues?{self.query_params}"

libs/langchain/tests/unit_tests/document_loaders/test_github.py

@@ -15,6 +15,21 @@ def test_initialization() -> None:
     }
 
 
+def test_initialization_ghe() -> None:
+    loader = GitHubIssuesLoader(
+        repo="repo",
+        access_token="access_token",
+        github_api_url="https://github.example.com/api/v3",
+    )
+    assert loader.repo == "repo"
+    assert loader.access_token == "access_token"
+    assert loader.github_api_url == "https://github.example.com/api/v3"
+    assert loader.headers == {
+        "Accept": "application/vnd.github+json",
+        "Authorization": "Bearer access_token",
+    }
+
+
 def test_invalid_initialization() -> None:
     # Invalid parameter
     with pytest.raises(ValueError):