feat: Coverage (#4)

* Added coverage; branch-level

* Handling complex branching coverage

* Using templates for coverage

* Added report-missing

* Added ty

* Add JUnit XML reporter, pyproject.toml config, exclude patterns, and block coverage

* Fixed build

* Bump test coverage

* Addressed AI reviews

Author: regularkevvv

.github/workflows/ci.yml

@@ -17,6 +17,7 @@ jobs:
       - uses: astral-sh/setup-uv@v7
       - run: uv python install ${{ matrix.python-version }}
       - run: uv sync --all-extras --dev
+      - run: uv build --wheel -q  # generates _templates.py via build hook
       - run: uv run coverage run -m pytest -q && uv run coverage report --fail-under=90
 
   lint:
@@ -25,5 +26,6 @@ jobs:
       - uses: actions/checkout@v5
       - uses: astral-sh/setup-uv@v7
       - run: uv sync --all-extras --dev
+      - run: uv build --wheel -q  # generates _templates.py via build hook
       - run: uv run ruff check .
       - run: uv run ruff format --check .

.gitignore

@@ -6,6 +6,9 @@ dist/
 wheels/
 *.egg-info
 
+# Cache
+.cache
+
 # Virtual environments
 .venv
 
@@ -18,4 +21,7 @@ uv.lock
 # Coverage
 .coverage
 htmlcov/
-*,cover
+*,cover
+
+# Generated files
+jinjatest/coverage/_templates.py

Makefile

@@ -3,6 +3,7 @@
 lint:
 	uv run ruff check .
 	uv run ruff format --check .
+	uv run ty check .
 
 lint-fix:
 	uv run ruff check --fix .

README.md

@@ -7,12 +7,12 @@ Stop writing brittle substring assertions. Test your templates with structure, v
 ## Installation
 
 ```bash
-pip install jinjatest
+uv add jinjatest
 ```
 
 With YAML support:
 ```bash
-pip install jinjatest[yaml]
+uv add jinjatest[yaml]
 ```
 
 ## Why jinjatest?
@@ -403,6 +403,48 @@ spec = TemplateSpec.from_file("template.j2")
 spec.assert_variables_subset_of({"user_name", "plan", "items"})
 ```
 
+## Template Coverage
+
+Track branch coverage for your Jinja templates to ensure all conditional paths are tested.
+
+### Quick Start
+
+```bash
+pytest --jt-cov
+```
+
+### CLI Options
+
+| Option | Description |
+|--------|-------------|
+| `--jt-cov` | Enable template coverage |
+| `--jt-cov-fail-under=N` | Fail if coverage below N% |
+| `--jt-cov-report=TYPE` | Report type: `term`, `term-missing`, `term-verbose`, `html`, `json`, `xml` |
+| `--jt-cov-html=DIR` | HTML report directory |
+| `--jt-cov-json=FILE` | JSON report file |
+| `--jt-cov-xml=FILE` | JUnit XML report file |
+| `--jt-cov-exclude=PATTERN` | Glob pattern to exclude templates |
+
+### Configuration (pyproject.toml)
+
+```toml
+[tool.jinjatest.coverage]
+enabled = true
+fail_under = 80
+report = ["term", "html"]
+html_dir = "jt-htmlcov"
+exclude_patterns = ["**/vendor/**", "*.partial.j2"]
+```
+
+### What's Tracked
+
+- `{% if %}` / `{% elif %}` / `{% else %}` branches
+- `{% for %}` loops (body and else)
+- `{% macro %}` definitions
+- `{% block %}` definitions (template inheritance)
+- `{% include %}` statements
+- Ternary expressions (`{{ x if cond else y }}`)
+
 ## License
 
 MIT

jinjatest/__init__.py

@@ -97,6 +97,7 @@ def test_welcome_pro_user():
     "TemplateMarkers",
     # Utilities
     "normalize_text",
+    # Coverage (lazy import via jinjatest.coverage)
 ]
 
 # Optional YAML exports

jinjatest/coverage/__init__.py

@@ -0,0 +1,75 @@
+"""
+Jinja template branch coverage tracking.
+
+This module provides automatic branch coverage tracking for Jinja templates.
+
+Example:
+    from jinjatest.coverage import (
+        get_coverage_collector,
+        CoverageReporter,
+        ReportConfig,
+    )
+
+    # Enable coverage collection
+    collector = get_coverage_collector()
+    collector.enable()
+
+    # ... run tests with TemplateSpec ...
+
+    # Generate reports
+    summary = collector.get_summary()
+    reporter = CoverageReporter(ReportConfig(fail_under=80))
+    reporter.terminal_report(summary)
+"""
+
+from jinjatest.coverage.collector import (
+    CoverageCollector,
+    CoverageSummary,
+    get_coverage_collector,
+    reset_coverage_collector,
+    set_coverage_collector,
+)
+from jinjatest.coverage.discovery import (
+    BranchDiscovery,
+    BranchInfo,
+    DiscoveryResult,
+)
+from jinjatest.coverage.instrumenter import (
+    AutoInstrumenter,
+    InstrumentationResult,
+)
+from jinjatest.coverage.reporter import (
+    CoverageReporter,
+    HTMLReporter,
+    JSONReporter,
+    JUnitReporter,
+    ReportConfig,
+    TerminalReporter,
+)
+from jinjatest.coverage.tracker import (
+    BranchCoverage,
+    TemplateCoverage,
+    TemplateCoverageStats,
+)
+
+__all__ = [
+    "CoverageCollector",
+    "CoverageSummary",
+    "get_coverage_collector",
+    "set_coverage_collector",
+    "reset_coverage_collector",
+    "BranchDiscovery",
+    "BranchInfo",
+    "DiscoveryResult",
+    "AutoInstrumenter",
+    "InstrumentationResult",
+    "TemplateCoverage",
+    "TemplateCoverageStats",
+    "BranchCoverage",
+    "CoverageReporter",
+    "TerminalReporter",
+    "JSONReporter",
+    "HTMLReporter",
+    "JUnitReporter",
+    "ReportConfig",
+]