Author: duke

[Must Read Part 1]

In addition to automated tests, organizations using continuous integration typically use build tools to implement continuous quality control. In addition to running unit and integration tests, such tools can run additional static and dynamic tests, measure and profile performance, extract and format documentation from the source code, and facilitate manual quality assurance processes. This continuous application of quality control aims to improve the quality of the product as well as reduce the time taken to deliver it by replacing the traditional practice of applying quality control after completing all development.

Build tools can be linked to automatic deployment tools, which can fetch the appropriate build from the continuous integration or build server and deploy it into one or more development, test, staging, or even production environments. This reduces the errors and delays associated with relying on specialized staff or programmers to install releases in these environments.

Continuous integration can provide the following benefits:

• Allows earlier detection and easier root cause analysis of integration problems and conflicting changes
• Gives the development team regular feedback on whether the code is working
• Keeps the version of the software being tested within a day of the version being developed
• Reduces regression risk associated with developer code refactoring due to rapid re-testing of the code base after each small set of changes
• Provides confidence that each day’s development work is based on a solid foundation
• Makes progress toward the completion of the product increment visible, encouraging
• developers and testers
• Eliminates the schedule risks associated with big-bang integration
• Provides constant availability of executable software throughout the sprint for testing,
• demonstration, or education purposes
• Reduces repetitive manual testing activities
• Provides quick feedback on decisions made to improve quality and tests

However, continuous integration is not without its risks and challenges:

• Continuous integration tools have to be introduced and maintained
• The continuous integration process must be defined and established
• Test automation requires additional resources and can be complex to establish
• Thorough test coverage is essential to achieve automated testing advantages
• Teams sometimes over-rely on unit tests and perform too little system and acceptance testing
  
  

Continuous integration requires the use of tools, including tools for testing, tools for automating the build process, and tools for version control.

Delivery of a product increment requires reliable, working, integrated software at the end of every sprint. Continuous integration addresses this challenge by merging all changes made to the software and integrating all changed components regularly, at least once a day. Configuration management, compilation, software build, deployment, and testing are wrapped into a single, automated, repeatable process. Since developers integrate their work constantly, build constantly, and test constantly, defects in code are detected more quickly.

Following the developers’ coding, debugging, and check-in of code into a shared source code repository, a continuous integration process consists of the following automated activities:

• Static code analysis: executing static code analysis and reporting results
• Compile: compiling and linking the code, generating the executable files
• Unit test: executing the unit tests, checking code coverage and reporting test results
• Deploy: installing the build into a test environment
• Integration test: executing the integration tests and reporting results
• Report (dashboard): posting the status of all these activities to a publicly visible location or emailing status to the team

An automated build and test process takes place on a daily basis and detects integration errors early and quickly. Continuous integration allows Agile testers to run automated tests regularly, in some cases as part of the continuous integration process itself, and send quick feedback to the team on the quality of the code. These test results are visible to all team members, especially when automated reports are integrated into the process. Automated regression testing can be continuous throughout the iteration. Good automated regression tests cover as much functionality as possible, including user stories delivered in the previous iterations. Good coverage in the automated regression tests helps support building (and testing) large integrated systems. When the regression testing is automated, the Agile testers are freed to concentrate their manual testing on new features, implemented changes, and confirmation testing of defect fixes.

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