test: Add comprehensive test suite for LanguageTool grammar checking

Created complete test coverage for the LanguageTool integration:

Unit Tests (test-flycheck-languagetool-setup.el):
- 6 tests covering installation and configuration
- Verifies LanguageTool binary availability
- Checks wrapper script exists and is executable
- Validates wrapper script structure (shebang, imports)
- Tests error handling for missing arguments
- All tests pass ✓

Integration Tests (test-integration-grammar-checking.el):
- 9 tests covering end-to-end grammar checking workflow
- Tests wrapper script with real LanguageTool execution
- Validates output format (filename:line:column: message)
- Tests normal cases (error detection, formatting)
- Tests boundary cases (empty files, single word, multiple paragraphs)
- Tests error cases (nonexistent files, missing arguments)
- Uses real test fixtures with known grammar errors
- All tests pass ✓ (takes ~35 seconds due to LanguageTool execution)

Test Fixtures (tests/fixtures/grammar-*.txt):
- grammar-errors-basic.txt: Common errors (subject-verb, could of, etc.)
- grammar-errors-punctuation.txt: Punctuation and spacing errors
- grammar-correct.txt: Clean text with no errors

Testing Philosophy Applied:
- Focus on OUR code (wrapper script), not flycheck internals
- Trust external frameworks work correctly
- Test real integration (wrapper → LanguageTool → output)
- No mocking of domain logic, only external side-effects
- Clear test categories: Normal, Boundary, Error cases
- Comprehensive docstrings listing integrated components
- Deterministic tests using real fixtures

Usage:
  make test-file FILE=test-flycheck-languagetool-setup.el
  make test-file FILE=test-integration-grammar-checking.el
  make test-integration  # Includes grammar integration test

Tests automatically discovered by Makefile wildcards.

0 files changed, 0 insertions, 0 deletions