Chapter 15: Coverage metrics (15a)

flasky.py

@@ -1,4 +1,12 @@
 import os
+
+COV = None
+if os.environ.get('FLASK_COVERAGE'):
+    import coverage
+    COV = coverage.coverage(branch=True, include='app/*')
+    COV.start()
+
+import sys
 import click
 from flask_migrate import Migrate
 from app import create_app, db
@@ -15,12 +23,29 @@ def make_shell_context():
 
 
 @app.cli.command()
+@click.option('--coverage/--no-coverage', default=False,
+              help='Run tests under code coverage.')
 @click.argument('test_names', nargs=-1)
-def test(test_names):
+def test(coverage, test_names):
     """Run the unit tests."""
+    if coverage and not os.environ.get('FLASK_COVERAGE'):
+        import subprocess
+        os.environ['FLASK_COVERAGE'] = '1'
+        sys.exit(subprocess.call(sys.argv))
+
     import unittest
     if test_names:
         tests = unittest.TestLoader().loadTestsFromNames(test_names)
     else:
         tests = unittest.TestLoader().discover('tests')
     unittest.TextTestRunner(verbosity=2).run(tests)
+    if COV:
+        COV.stop()
+        COV.save()
+        print('Coverage Summary:')
+        COV.report()
+        basedir = os.path.abspath(os.path.dirname(__file__))
+        covdir = os.path.join(basedir, 'tmp/coverage')
+        COV.html_report(directory=covdir)
+        print('HTML version: file://%s/index.html' % covdir)
+        COV.erase()

requirements/dev.txt

@@ -1,6 +1,7 @@
 -r common.txt
 certifi==2017.7.27.1
 chardet==3.0.4
+coverage==4.4.1
 faker==0.7.18
 httpie==0.9.9
 idna==2.5