Given the close association of testers with developers in agile, and the nature of incremental testing of partial work products, the tasks that testers perform may sometime seem hazy. Would testers do the unit testing on the partially implemented or incremental bits of code ? Or would testers duplicate the unit tests that developers have already run ?
The role of testers in agile is not to perform the unit tests of programmers nor to duplicate the unit tests that developers perform. Agile testers perform a significant amount of manual (yes, manual) exploratory type testing. The purpose of these tests is to reveal issues which the unit tests would not have discovered. The exploratory tests need to be as wide as possible, meaning they need to get to as end-to-end an effort as possible. Given that unit tests focus on the specific module or area of code, the exploratory tests which focus on the interactions between modules and user scenarios tend to throw up issues that were not found earlier. Such end-to-end tests find issues quicker.
For testers to be able to successfully operate in an agile environment, it is important that they be familiar with the tools-of-the-trade. Testers need to know the language used in development, be able to checkout and build the source code, work with the development environment (IDEs, version control, continuous build integration systems, unit test frameworks such as xUnit, etc), be able to configure the system and its dependencies, wherever needed write code / scripts to workaround any as yet undeveloped interfaces or harness, add to the existing automation suites as needed, be able to work together and communicate comfortably with programmers.
The role of testers in agile is not to perform the unit tests of programmers nor to duplicate the unit tests that developers perform. Agile testers perform a significant amount of manual (yes, manual) exploratory type testing. The purpose of these tests is to reveal issues which the unit tests would not have discovered. The exploratory tests need to be as wide as possible, meaning they need to get to as end-to-end an effort as possible. Given that unit tests focus on the specific module or area of code, the exploratory tests which focus on the interactions between modules and user scenarios tend to throw up issues that were not found earlier. Such end-to-end tests find issues quicker.
For testers to be able to successfully operate in an agile environment, it is important that they be familiar with the tools-of-the-trade. Testers need to know the language used in development, be able to checkout and build the source code, work with the development environment (IDEs, version control, continuous build integration systems, unit test frameworks such as xUnit, etc), be able to configure the system and its dependencies, wherever needed write code / scripts to workaround any as yet undeveloped interfaces or harness, add to the existing automation suites as needed, be able to work together and communicate comfortably with programmers.
