Add codebase improvement roadmap and fix brittle test assertions

docs/codebase_improvements.md

@@ -0,0 +1,100 @@
+# Codebase improvement plan
+
+This document summarizes high-impact opportunities to improve maintainability, reliability, and release quality for `scholarly`.
+
+## 1) Modernize packaging metadata (high impact, low-medium effort)
+
+### Current state
+- `pyproject.toml` only declares the build backend, while package metadata and dependencies are still maintained in `setup.py`.
+- `setup.py` still marks the package as `Development Status :: 3 - Alpha`.
+- Test configuration uses a legacy `test_suite` setting.
+
+### Why improve
+- Keeping metadata in a single source of truth (`pyproject.toml` under PEP 621) reduces drift between tools.
+- A modern packaging layout improves compatibility with build tooling and dependency scanners.
+
+### Recommended actions
+1. Move project metadata and dependencies from `setup.py` into `pyproject.toml` (`[project]`, `[project.optional-dependencies]`).
+2. Keep `setup.py` as a thin compatibility shim (or remove when downstream tooling allows).
+3. Add tool config blocks for formatter/linter/test runner (`[tool.pytest.ini_options]`, etc.) if adopted.
+4. Revisit package classifier maturity to match actual support expectations.
+
+---
+
+## 2) Split online integration tests from deterministic unit tests (high impact, medium effort)
+
+### Current state
+- `test_module.py` performs many live requests against Google Scholar and free-proxy providers.
+- The default setup path calls `FreeProxies()` and can fail in CI/restricted networks with proxy errors.
+
+### Why improve
+- Network and anti-bot behavior make these tests flaky and environment-dependent.
+- Contributors cannot reliably run tests offline.
+
+### Recommended actions
+1. Introduce explicit test markers/categories:
+   - `unit` (pure parsing/logic, deterministic)
+   - `integration` (live network)
+2. Move parsing assertions to fixture-based tests with stored HTML snippets.
+3. Gate live tests behind an opt-in env var (for example `SCHOLARLY_RUN_LIVE_TESTS=1`) and skip by default.
+4. Add CI matrix stages for quick deterministic checks vs scheduled/optional live checks.
+
+---
+
+## 3) Tighten exception boundaries and diagnostics around proxy/navigation (high impact, medium effort)
+
+### Current state
+- Navigation/proxy code contains many broad `except Exception` handlers.
+- Retries are spread across navigator and proxy layers with mixed logging detail.
+
+### Why improve
+- Broad exception handling can hide root causes.
+- Harder to reason about retry policy and failure modes across multiple connection paths.
+
+### Recommended actions
+1. Replace generic catches with specific exception classes where feasible (`requests`, `httpx`, Selenium, parsing errors).
+2. Standardize retry policy in one place (max attempts, backoff, timeout growth).
+3. Return/raise structured errors that preserve context (request URL, proxy mode, status code).
+4. Add focused unit tests for retry/fallback paths with mocked sessions.
+
+---
+
+## 4) Improve API typing and static analysis coverage (medium impact, medium effort)
+
+### Current state
+- Some modules have selective type hints; many public methods still have partial/no type coverage.
+- Dynamic dictionary payloads are common and can be error-prone.
+
+### Why improve
+- Better typing helps contributors navigate the code and reduces regressions.
+- Static analysis can catch interface mismatches early.
+
+### Recommended actions
+1. Incrementally type annotate public methods in `_scholarly.py`, `_navigator.py`, and parsers.
+2. Introduce `TypedDict`/dataclass models for frequently used payload shapes.
+3. Add `mypy` (or pyright) in non-blocking mode first, then tighten gradually.
+
+---
+
+## 5) Documentation and contributor experience upgrades (medium impact, low effort)
+
+### Current state
+- README and docs are comprehensive but test execution guidance assumes network-dependent flows.
+- Contributor guidance could more clearly separate quick local checks from full integration validation.
+
+### Why improve
+- Faster onboarding and fewer false-negative test runs for external contributors.
+
+### Recommended actions
+1. Add a short “Local development quick checks” section with deterministic commands.
+2. Document required environment variables/services for each integration test category.
+3. Add troubleshooting notes for common proxy/network failures.
+
+---
+
+## Quick wins already applied in this branch
+
+- Replaced two identity assertions (`assertIs(..., 0)`) with value assertions (`assertEqual(..., 0)`) in tests.
+- Fixed a typo in a test docstring (`fiile` -> `file`).
+
+These are small quality improvements that reduce brittle test style and clean up minor docs noise.

test_module.py

@@ -100,7 +100,7 @@ def setUpClass(cls):
     @classmethod
     def tearDownClass(cls):
         """
-        Clean up the mandates csv fiile downloaded.
+        Clean up the mandates csv file downloaded.
         """
         if os.path.exists(cls.mandates_filename):
             os.remove(cls.mandates_filename)
@@ -121,7 +121,7 @@ def test_search_author_empty_author(self):
         Test that sholarly.search_author('') returns no authors
         """
         authors = [a for a in scholarly.search_author('')]
-        self.assertIs(len(authors), 0)
+        self.assertEqual(len(authors), 0)
 
     def test_search_keywords(self):
         query = scholarly.search_keywords(['crowdsourcing', 'privacy'])
@@ -653,7 +653,7 @@ def test_search_pubs_empty_publication(self):
         Test that searching for an empty publication returns zero results
         """
         pubs = [p for p in scholarly.search_pubs('')]
-        self.assertIs(len(pubs), 0)
+        self.assertEqual(len(pubs), 0)
 
     def test_search_pubs_citedby(self):
         """