[refactor]: Refactored the initialization of issue_handler within IssueResolver (#8417)

Co-authored-by: Rohit Malhotra <rohitvinodmalhotra@gmail.com>

tests/unit/resolver/test_issue_handler_factory.py

@@ -0,0 +1,77 @@
+from typing import Type
+from unittest.mock import MagicMock
+
+import pytest
+from pydantic import SecretStr
+
+from openhands.core.config import LLMConfig
+from openhands.integrations.provider import ProviderType
+from openhands.resolver.interfaces.github import GithubIssueHandler, GithubPRHandler
+from openhands.resolver.interfaces.gitlab import GitlabIssueHandler, GitlabPRHandler
+from openhands.resolver.issue_handler_factory import IssueHandlerFactory
+from openhands.resolver.interfaces.issue_definitions import (
+    ServiceContextIssue,
+    ServiceContextPR,
+)
+
+
+@pytest.fixture
+def llm_config():
+    return LLMConfig(
+        model='test-model',
+        api_key=SecretStr('test-key'),
+    )
+
+
+@pytest.fixture
+def factory_params(llm_config):
+    return {
+        'owner': 'test-owner',
+        'repo': 'test-repo',
+        'token': 'test-token',
+        'username': 'test-user',
+        'base_domain': 'github.com',
+        'llm_config': llm_config,
+    }
+
+
+test_cases = [
+    # platform, issue_type, expected_context_type, expected_handler_type
+    (ProviderType.GITHUB, 'issue', ServiceContextIssue, GithubIssueHandler),
+    (ProviderType.GITHUB, 'pr', ServiceContextPR, GithubPRHandler),
+    (ProviderType.GITLAB, 'issue', ServiceContextIssue, GitlabIssueHandler),
+    (ProviderType.GITLAB, 'pr', ServiceContextPR, GitlabPRHandler),
+]
+
+
+@pytest.mark.parametrize(
+    'platform,issue_type,expected_context_type,expected_handler_type',
+    test_cases
+)
+def test_handler_creation(
+    factory_params,
+    platform: ProviderType,
+    issue_type: str,
+    expected_context_type: Type,
+    expected_handler_type: Type,
+):
+    factory = IssueHandlerFactory(
+        **factory_params,
+        platform=platform,
+        issue_type=issue_type
+    )
+    
+    handler = factory.create()
+    
+    assert isinstance(handler, expected_context_type)
+    assert isinstance(handler._strategy, expected_handler_type)
+
+def test_invalid_issue_type(factory_params):
+    factory = IssueHandlerFactory(
+        **factory_params,
+        platform=ProviderType.GITHUB,
+        issue_type='invalid'
+    )
+    
+    with pytest.raises(ValueError, match='Invalid issue type: invalid'):
+        factory.create()