Shift-left testing in Testing Fundamentals - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is Shift-left testing?

Shift-left testing means starting testing activities early in the software development process, usually during requirements and design phases, to find defects sooner.

beginner

Why is Shift-left testing beneficial?

It helps catch bugs early, reduces cost and effort to fix defects, and improves software quality by preventing problems before coding is complete.

beginner

Which phase is testing moved to in Shift-left testing?

Testing is moved to earlier phases like requirements analysis and design instead of waiting until after coding is done.

intermediate

Give an example of a Shift-left testing activity.

Reviewing requirements for errors or ambiguities before coding starts is a Shift-left testing activity.

intermediate

How does Shift-left testing affect collaboration?

It encourages developers, testers, and business analysts to work together early, improving communication and shared understanding.

What does Shift-left testing primarily focus on?

A Testing only the user interface

B Starting testing early in the development process

C Skipping testing to save time

D Testing only after coding is complete

Shift-left testing means moving testing activities to earlier stages to find defects sooner.

Which phase is NOT typically involved in Shift-left testing?

A Unit testing

B Design review

C Requirements analysis

D Post-release maintenance

Shift-left testing focuses on early phases, not post-release maintenance.

What is a key benefit of Shift-left testing?

A Finding defects late in the process

B Ignoring requirements

C Reducing cost to fix bugs

D Delaying testing until deployment

Finding defects early reduces the cost and effort to fix them.

Which activity aligns with Shift-left testing?

A Code review during development

B Final system testing after deployment

C User acceptance testing only

D Skipping unit tests

Code reviews during development help catch defects early, fitting Shift-left testing.

Shift-left testing encourages collaboration between:

A Developers and testers early in the process

B Only testers after coding

C Users and marketing teams only

D Operations and support teams only

Early collaboration between developers and testers improves quality and understanding.

Explain what Shift-left testing is and why it is important.

Think about when testing happens and its benefits.

Describe some activities or practices that support Shift-left testing.

Consider what testers and developers do before coding finishes.

Practice

1. What is the main idea behind shift-left testing?

easy

A. Testing only the user interface at the end

B. Testing early in the software development process

C. Testing only after the software is fully developed

D. Testing only by the quality assurance team

Solution

1. Step 1: Understand the term 'shift-left'

   Shift-left means moving testing activities to earlier stages in development.

2. Step 2: Compare options with the definition

   Only Testing early in the software development process describes testing early, others describe late or limited testing.

3. Final Answer:

   Testing early in the software development process -> Option B

4. Quick Check:

   Shift-left = Early testing [OK]

Hint: Shift-left means test early, not late [OK]

Common Mistakes:

• Thinking testing happens only after coding
• Confusing shift-left with testing only UI
• Believing only QA team tests

2. Which of the following is a common practice that supports shift-left testing?

easy

A. Writing tests after the product release

B. Performing only manual testing at the end

C. Test-driven development (TDD)

D. Skipping code reviews

Solution

1. Step 1: Identify practices that enable early testing

   TDD means writing tests before or during coding, supporting early testing.

2. Step 2: Eliminate options that delay or skip testing

   Options A, B, and C delay or reduce testing, not shift it left.

3. Final Answer:

   Test-driven development (TDD) -> Option C

4. Quick Check:

   TDD = Early testing practice [OK]

Hint: TDD means write tests first, fits shift-left [OK]

Common Mistakes:

• Thinking tests come only after release
• Ignoring code reviews as testing support
• Believing manual testing only is enough

3. Consider this code snippet representing a testing timeline:

Development Start -> Code Review -> Unit Testing -> Integration Testing -> Release

Which step best represents the shift-left testing approach?

medium

A. Unit Testing

B. Release

C. Code Review

D. Integration Testing

Solution

1. Step 1: Understand shift-left means testing early

   Shift-left moves testing activities closer to development start.

2. Step 2: Identify earliest testing-related step

   Unit Testing is the earliest formal testing phase after code review, which is a review step but not a testing activity.

3. Final Answer:

   Unit Testing -> Option A

4. Quick Check:

   Shift-left = Early testing phases like unit testing [OK]

Hint: Shift-left means test as early as possible [OK]

Common Mistakes:

• Choosing testing steps that happen later
• Confusing release with testing
• Ignoring code review as testing support

4. A team claims they follow shift-left testing but only start testing after full coding is done. What is the main problem in their approach?

medium

A. They are not testing early enough

B. They are testing too early

C. They are using too many automated tests

D. They are skipping integration testing

Solution

1. Step 1: Recall shift-left means testing early

   Testing after full coding is late, not early.

2. Step 2: Identify the problem with their timing

   The team delays testing, so they miss shift-left benefits.

3. Final Answer:

   They are not testing early enough -> Option A

4. Quick Check:

   Shift-left = test early, not late [OK]

Hint: Shift-left means test early, not after coding done [OK]

Common Mistakes:

• Thinking testing too early is a problem
• Confusing automation with timing
• Ignoring integration testing relevance

5. A project uses shift-left testing by integrating automated unit tests early. However, bugs still appear late in integration testing. What is a likely cause?

hard

A. Manual testing should replace automated tests

B. Automated tests are run too early in development

C. Shift-left testing means skipping integration tests

D. Unit tests do not cover integration points between modules

Solution

1. Step 1: Understand shift-left testing scope

   Shift-left encourages early testing but does not replace integration testing.

2. Step 2: Analyze why bugs appear late despite early unit tests

   Unit tests check individual parts but may miss how parts work together.

3. Step 3: Identify the cause of late bugs

   Missing coverage of integration points causes bugs to appear late.

4. Final Answer:

   Unit tests do not cover integration points between modules -> Option D

5. Quick Check:

   Early unit tests ≠ full integration coverage [OK]

Hint: Unit tests check parts, integration tests check connections [OK]

Common Mistakes:

• Thinking shift-left skips integration testing
• Believing running tests early causes bugs
• Replacing automated tests with manual only