Coverage in CI pipelines in PyTest - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to run pytest with coverage reporting.

PyTest

pytest --cov=[1] tests/

Drag options to blanks, or click blank then click option'

Amy_module

Btests

Csetup.py

Ddocs

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'tests' as the coverage target instead of the main module.

The --cov option specifies the module to measure coverage for. It should be the main code folder, not the tests folder.

2fill in blank

medium

Complete the pytest command to generate a coverage report in XML format for CI tools.

PyTest

pytest --cov=my_module --cov-report=[1] tests/

Drag options to blanks, or click blank then click option'

Aterm

Bhtml

Cxml

Dannotate

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'html' instead of 'xml' for CI coverage reports.

The xml report format is commonly used in CI pipelines to integrate with coverage tools.

3fill in blank

hard

Fix the error in the pytest coverage command to include branch coverage.

PyTest

pytest --cov=my_module --cov-report=xml --cov-branch=[1] tests/

Drag options to blanks, or click blank then click option'

Atrue

Byes

C1

Don

Attempts:

3 left

💡 Hint

Common Mistakes

Using 'yes' or 'on' which are not recognized by pytest-cov.

The correct option to enable branch coverage is --cov-branch=true.

4fill in blank

hard

Fill both blanks to configure pytest coverage to fail if coverage is below 80% and to show the report in the terminal.

PyTest

pytest --cov=my_module --cov-fail-under=[1] --cov-report=[2] tests/

Drag options to blanks, or click blank then click option'

A80

Bterm

Chtml

D70

Attempts:

3 left

💡 Hint

Common Mistakes

Setting fail-under too low or using 'html' instead of 'term' for terminal output.

The --cov-fail-under=80 option makes the test fail if coverage is below 80%. The term report shows coverage in the terminal.

5fill in blank

hard

Fill all four blanks to create a pytest coverage command that measures coverage, generates XML and HTML reports, and fails if coverage is below 90%.

PyTest

pytest --cov=[1] --cov-report=[2] --cov-report=[3] --cov-fail-under=[4] tests/

Drag options to blanks, or click blank then click option'

Amy_module

Bxml

Chtml

D90

Attempts:

3 left

💡 Hint

Common Mistakes

Forgetting to specify the module or mixing up report formats.

This command measures coverage on my_module, outputs XML and HTML reports, and fails if coverage is below 90%.

Practice

1. What is the main purpose of using coverage tools like pytest --cov in CI pipelines?

easy

A. To generate user documentation

B. To speed up the test execution time

C. To deploy the application automatically

D. To measure how much of the code is tested automatically

Solution

1. Step 1: Understand coverage tools in testing

   Coverage tools measure the percentage of code executed by tests.

2. Step 2: Role in CI pipelines

   In CI, coverage helps ensure tests cover enough code to catch bugs early.

3. Final Answer:

   To measure how much of the code is tested automatically -> Option D

4. Quick Check:

   Coverage measures tested code = D [OK]

Hint: Coverage shows tested code percentage in CI [OK]

Common Mistakes:

• Confusing coverage with test speed
• Thinking coverage deploys code
• Assuming coverage creates docs

2. Which of the following is the correct command to run pytest with coverage reporting?

easy

A. pytest --cov=.

B. pytest --cov-report=html --cov

C. pytest -coverage

D. pytest --coverage=report

Solution

1. Step 1: Identify correct pytest coverage syntax

   The correct syntax uses --cov to specify coverage on the current directory.

2. Step 2: Analyze options

   pytest --cov=. correctly runs coverage on the current directory with default terminal reporting.

3. Final Answer:

   pytest --cov=. -> Option A

4. Quick Check:

   Correct pytest coverage command = B [OK]

Hint: Use --cov and --cov-report together for coverage output [OK]

Common Mistakes:

• Using incorrect flags like --coverage=report
• Missing --cov option
• Wrong flag syntax like -coverage

3. Given this pytest command in a CI pipeline:

pytest --cov=myapp --cov-report=term

What will be the output shown in the CI logs?

medium

A. A summary of coverage percentages printed in the terminal

B. No coverage information will be shown

C. A detailed HTML coverage report saved to disk

D. An error because --cov-report=term is invalid

Solution

1. Step 1: Understand --cov-report=term option

   The term option prints coverage summary in the terminal output.

2. Step 2: Analyze expected CI log output

   The CI logs will show coverage percentages summary, not an HTML file or error.

3. Final Answer:

   A summary of coverage percentages printed in the terminal -> Option A

4. Quick Check:

   --cov-report=term shows summary in terminal = C [OK]

Hint: term report prints coverage summary in console [OK]

Common Mistakes:

• Expecting HTML report in terminal
• Assuming no coverage output
• Thinking --cov-report=term is invalid

4. You added coverage to your CI pipeline with this command:

pytest --cov=myapp --cov-report=html

But the coverage report is missing after the run. What is the most likely cause?

medium

A. The --cov option is misspelled

B. The coverage report is saved in a different directory, not checked by CI

C. pytest does not support coverage reporting

D. The tests did not run because of a syntax error

Solution

1. Step 1: Understand where coverage HTML reports are saved

   By default, HTML reports are saved in a folder named htmlcov in the current directory.

2. Step 2: Check CI pipeline file handling

   If the CI pipeline does not collect or upload this folder, the report will appear missing.

3. Final Answer:

   The coverage report is saved in a different directory, not checked by CI -> Option B

4. Quick Check:

   HTML report saved in htmlcov folder = A [OK]

Hint: Check htmlcov folder location in CI artifacts [OK]

Common Mistakes:

• Assuming --cov is misspelled without checking
• Believing pytest lacks coverage support
• Ignoring test run errors

5. In a CI pipeline, you want to fail the build if coverage falls below 80%. Which pytest coverage option helps enforce this?

hard

A. --fail-if-coverage-below=80

B. --coverage-threshold=80

C. --cov-fail-under=80

D. --cov-minimum=80

Solution

1. Step 1: Identify pytest coverage option for minimum coverage

   The correct option is --cov-fail-under which sets a minimum coverage percentage.

2. Step 2: Understand CI build failure behavior

   If coverage is below the set value, pytest returns a failure status causing CI to fail the build.

3. Final Answer:

   --cov-fail-under=80 -> Option C

4. Quick Check:

   Fail build if coverage under 80% = B [OK]

Hint: Use --cov-fail-under to enforce coverage minimum [OK]

Common Mistakes:

• Using incorrect or non-existent flags
• Confusing coverage reporting with build failure
• Assuming coverage threshold is set elsewhere