Address Test Coverage Gaps

[mwaddell]

Missing Edge-Case Tests

This checklist records edge cases identified during the unit-test coverage
review. Each item should be marked complete only after a focused unit test is
added and passing.

Command-Line Configuration

• Verify main() rejects --api google when no API key is supplied by
  --apiKey, the environment, or .env.
• Verify main() rejects --api geocodio when no API key is supplied by
  --apiKey, the environment, or .env.
• Verify main() accepts a CLI API key for a keyed provider.
• Verify main() accepts an API key supplied through the environment.
• Verify main() accepts an API key loaded from .env.
• Verify .env parsing accepts trimmed and quoted KEY=value values.
• Verify .env parsing ignores blank lines, comments, and malformed lines.
• Verify existing environment variables take precedence over .env values.

Relevant code: src/geocoder.py:69-89, src/geocoder.py:397-401.

Workbook Input

• Verify a None header cell is ignored while recognized header cells are
  still detected.
• Verify fully blank input rows are skipped and do not create output rows.
• Verify blank rows do not disrupt sequential record IDs or provider-result
  alignment.
• Verify a short row with missing optional cells is treated as having blank
  values rather than raising an indexing error.
• Verify a valid header-only worksheet produces an output sheet with headers
  and no data rows without making provider requests.
• Verify an empty worksheet is skipped when another worksheet is valid.
• Verify a workbook containing only empty worksheets exits without creating
  an output file.

Relevant code: src/geocoder.py:100-167, src/geocoder.py:280-302.

Shared Provider Behavior

• Verify the expected behavior when a provider fetch yields fewer responses
  than requested records. Decide whether missing responses should become
  no-matches or raise a descriptive error.
• Verify an empty input record list does not make provider requests and
  returns an empty result list.

Relevant code: src/api.py:256-292.

Census Provider

• Verify a Census response row with an unknown internal ID is rejected or
  handled according to an explicitly documented policy.
• Verify malformed Census row IDs, including blank and non-numeric values,
  produce a descriptive error.
• Verify undersized non-match and tie rows are handled or rejected with a
  descriptive error.
• Verify records are split at BATCH_SIZE boundaries and all batches retain
  input-result ordering.

Relevant code: src/census.py:79-110.

Google Provider

• Verify a Google OK response with a missing or empty results list is
  handled without an unhelpful KeyError or IndexError.
• Verify a Google result with missing geometry or location fields has
  defined coordinate behavior.
• Verify malformed address_components entries produce a descriptive error
  or are safely ignored according to an explicit policy.

Relevant code: src/google.py:84-100, src/google.py:120-175.

Geocodio Provider

• Verify an entry missing response or response.results is handled
  without an unhelpful KeyError or AttributeError.
• Verify a malformed first Geocodio candidate, such as one missing
  location or address_components, has defined behavior.
• Verify records are split at BATCH_SIZE boundaries and all batches retain
  input-result ordering.

Relevant code: src/geocodio.py:60-98, src/geocodio.py:118-162.

Legacy Launcher

• Add a subprocess smoke test for the root geocoder.py launcher if it is
  intentionally supported alongside the installed geocoder command.
• Remove the root launcher instead if the installed console entry point is
  the only supported interface.

Relevant code: geocoder.py:8-11.