The Difference Between Component Testing and Unit Testing

Difference Between Component Testing and Unit Testing

The Difference Between Component Testing and Unit Testing

Understanding the hierarchy of testing is elementary for QA practices, it helps us keep all activities coordinated with one another and stabilize what could be a long and tedious procedure. For that reason, we at Q-Pros have established a constructive approach for software testing to make sure our clients get guaranteed results.

In this article, we will look at the differences between Component Testing and Unit Testing and identify the specific comparing basis to distinguish the two essential levels of testing.

To begin with, we will start by identifying each method individually.

What is Unit Testing?

Unit testing is a software testing method which takes every unit of code into consideration for testing, to make sure that all code-sets are appropriate based on requirements and standard suitability before stepping further with the code building.

Computer data is examined to check if it fits or not. This is done to completely avoid any future errors that may become hard to detect if not dealt with sooner.

Unit testing is done by the developers, and it comes first in the hierarchy of testing levels.

What are the testing levels for software systems?

  • Unit testing: Unit testing takes top priority before stepping further into code.
  • Integration testing: Modules are combined and evaluated as one with specified functional requirements.
  • System testing: In system testing, we take all the integrated components that passed the test as input.
  • Acceptance testing: Finally, we measure the degree to which the application has met the user’s approval.

 In Unit testing, the word “Unit” means every element within the application that could be tested during the development stage.

What is Component Testing?

Component testing also referred to as module or program testing, is a test where each component of the system is tested individually without looking at integration in-between other components.

Each component receives an input, and then the data should be processed through the system and produce an output. This output will be examined based on requirements separately.

The main objective of this type of testing is to make sure that all components within a system are user-understandable and can be used individually.

Component testing is usually done by a developer before creating a new component.

Developers can choose to move to build a new component once all identified defects are fixed in a previous one.

Developers use this method to examine testing objects without integration, meaning that testing objects are tested separately from the whole design or any other components or modules.

The Differences between Component and Unit testing

After we have defined the two types, we can now start to look at each in comparison to the other to get a further understanding of how we can relate them in an overall testing strategy.

We will now look at key factors to differentiate the two kinds distinctly:

Comparing FactorUnit testingComponent testing
  ExecutionUnit testing is processed by the developers in the initial stagesComponent testing is performed by a team of testing engineers using various testing tools.
  Method usedWhite-box testing: Testing the application with knowledge of internal structures.Black-box testing: Testing the application with little to no internal knowledge of its code.
  ValidationValidates the efficiency and accuracy of the design documentsUses test cases and validates specific components.  
  Detecting error  Unit testing detects errors more easily.Component testing detects errors with more complexity than unit testing.
  Level of TestingUnit testing is performed at a granular level.Component testing is performed at the application level.

Unit and Component testing are fairly related, both require a level of segregation from the overall system. Component testing is done on an application level by testing experts, On the other hand, unit testing is done on an agranular level by developers.

It is also worth highlighting that component testing can only be done after unit testing.


Constant updates require constant testing. Before launching any application, requirements should be set and met. Q-Pros is a leading testing service provider with years of experience in accomplishing just that.

To know more about our testing approaches and to request a customized testing service, visit our online service request page now.