# Patent

## Title
Identifying a defect density

## Abstract

A technique to determine defect density in a portion or subset of code. Changes to code may be tracked. Defects in the code that are addressed by the changes may also be tracked. A defect density in a portion or subset of the code having a characteristic can be determined by identifying changes modifying the portion or subset of the code and that address a defect.

## Background
BACKGROUND
Development of software can be challenging. During the development of software, computer program code can be written by one or more developers. Often, complex software includes code written by teams of developers. Accordingly, different portions of the code can be written by different developers. In addition, the code can be written at different times, during different phases of the software development cycle. For example, original code may be reviewed and tested to identify defects in the code. Defects may be addressed by modifying the original code. New defects can sometimes be added to the software by the modifications.



BRIEF DESCRIPTION OF DRAWINGS
The following detailed description refers to the drawings, wherein:
FIG. 1 illustrates a computing system for determining a defect density, according to an example.
FIG. 2 illustrates a computing system for determining a defect density, according to an example.
FIG. 3 illustrates a use case in which a defect density can be determined based on multiple characteristics, according to an example.
FIG. 4 illustrates a method of determining a defect density, according to an example.
FIG. 5 illustrates a method of determining a second defect density and displaying the results, according to an example.
FIG. 6 illustrates a computer-readable medium for determining a defect density, according to an example.



DETAILED DESCRIPTION
According to an embodiment, a computing system can include a code tracker to track changes to a code base. The code base may be a collection of source code used to build a particular software program. The system may also include a defect tracker to track any defects addressed by the changes. A defect may be an error, flaw, mistake, failure, or fault in a computer program that produces an incorrect or unexpected result or that causes the program to behave in unintended ways. A defect may also be an indication that some aspect of the software does not meet a requirement for the software. A requirement may represent a feature, property, functionality, or the like, that the software is supposed to have.
The system may also include a defect density module. The defect density module may determine a number of defects in a portion of the code base having a characteristic. The characteristic may be at least one of an author and a requirement. For example, if the characteristic is an author, then the portion of the code base having the characteristic would be code that was authored by the author. If the characteristic is a requirement, then the portion of the code base having the characteristic would be code implementing the requirement. The defect density module may determine the number of defects in the portion of the code base having the characteristic by determining which changes addressing a defect occurred in the portion of the code base having the characteristic. Another characteristic that may be considered is a time period during which the code was produced. Characteristics may be combined as well, such that the portion of the code base may have all of the combined characteristics. For instance, the portion of the code base may include code authored by a particular author during a particular time period. Determining defect density in this manner may be advantageous for identifying trends and patterns and for improving code quality over time.
Further details of this embodiment and associated advantages, as well as of other embodiments, will be discussed in more detail below with reference to the drawings.
Referring now to the drawings, FIG. 1 illustrates a computing system for determining a defect density, according to an example. Computing system 100 may include and/or be implemented by one or more computers. For example, the computers may be server computers, workstation computers, desktop computers, or the like. The computers may include one or more controllers and one or more machine-readable storage media.
A controller may include a processor and a memory for implementing machine readable instructions. The code tracker 110, defect tracker 120, and defect density module 130 include software modules, one or more machine-readable media for storing the software modules, and one or more processors for executing the software modules. A software module may be a computer program comprising machine-executable instructions. The processor may include at least one central processing unit (CPU), at least one semiconductor-based microprocessor, at least one digital signal processor (DSP) such as a digital image processing unit, other hardware devices or processing elements suitable to retrieve and execute instructions stored in memory, or combinations thereof. The processor can include single or multiple cores on a chip, multiple cores across multiple chips, multiple cores across multiple devices, or combinations thereof. The processor may fetch, decode, and execute instructions from memory to perform various functions. As an alternative or in addition to retrieving and executing instructions, the processor may include at least one integrated circuit (IC), other control logic, other electronic circuits, or combinations thereof that include a number of electronic components for performing various tasks or functions.
Controller 130 may include memory, such as a machine-readable storage medium. The machine-readable storage medium may be any electronic, magnetic, optical, or other physical storage device that contains or stores executable instructions. Thus, the machine-readable storage medium may comprise, for example, various Random Access Memory (RAM), Read Only Memory (ROM), flash memory, and combinations thereof. For example, the machine-readable medium may include a Non-Volatile Random Access Memory (NVRAM), an Electrically Erasable Programmable Read-Only Memory (EEPROM), a storage drive, a NAND flash memory, and the like. Further, the machine-readable storage medium can be computer-readable and non-transitory. Additionally, computing system 100 may include one or more machine-readable storage media separate from the one or more controllers.
Computing system 100 may include code tracker 110, defect tracker 120, and defect density module 130. Each of these components may be implemented by a single computer or multiple computers. In addition, users of computing system 100 may interact with computing system 100 through one or more other computers, which may or may not be considered part of computing system 100. As an example, a software developer may interact with code tracker 110 via a computer application residing on another computer, such as a desktop computer, workstation computer, tablet computer, or the like.
Code tracker 110, defect tracker 120, and defect density module 130 may be considered to be functionality implemented by one or more components of a software development platform executed by computing system 100. The software development platform may be a single or multiple software applications that facilitate the development and management of software. For example, the platform may include a source code management program to manage the code base, track changes, and track the authors of the changes. The source code management program may maintain a copy of the code base and may accept changes to the code base from developers. The source code management program may thus maintain a history of the code base and may also manage conflicts, ensuring that the same portion of the code base is not simultaneously modified by different developers. The platform may also include a project management program, which can track requirements, facilitate testing, track defects, and provide analysis capabilities. The project management program can interface with the source code management program to link requirements and defects with portions of the code base, past changes, etc. The platform may also include an integrated development environment (IDE), which can provide a software development interface for software developers. The IDE can provide a user-friendly interface to developers for coding, checking code into the source code management program, indicating relevant information regarding requirements or defects that the code relates to, and the like. In some embodiments, the functionality of the code tracker 110, defect tracker 120, and defect density module 130 may be implemented by combinations of these components. Furthermore, in some examples, the software development platform can take a different form, with the various functionality being implemented by a single application or component or by different applications or component than described here.
Code tracker 110 may track changes to a code base. The code tracker 110 may maintain a copy of the code base. The code base may be the collection of source code used to build a particular software program being developed. Code tracker 110 may also manage changes (or modifications) to the code base. For example, code tracker 110 may accept a set of changes (sometimes referred to as a “change set”) from a first developer and another change set from a second developer to different portions of the code base and may maintain a history of the changes, such that prior versions of the code base may be reconstructed and such that changes to the code base can be traced. A change set may also include a new addition to the code base, such as a new class or software module. The code tracker 110 may also ensure that two developers do not modify the same portion of code at the same time.
Code tracker 110 may also record information regarding each change set. For example, code tracker 110 may record the author of the change set and the date that the change set was checked in to the code tracker. Code tracker 110 may record other information related to the purpose of the change set. For example, code tracker 110 may record which requirement the change set is meant to implement or which defect the change set is meant to address. In an example, the requirement or the defect may be entered by the developer.
During testing of the code base, a number of defects may be discovered. A defect may be an error, flaw, mistake, failure, or fault in the computer program that produces an incorrect or unexpected result or that causes the program to behave in unintended ways. Defects may be discovered automatically by automated tests run on the code base. For example, a set of unit tests may be designed to test the internal structure and workings of the software. This type of testing may be referred to as static testing. Dynamic testing may also be used to discover defects in the software. For example, simulated users, called testers, may test the functionality of the software and determine whether it meets the requirements for the software. As discussed previously, a requirement may represent a feature, property, functionality, or the like, that the software is supposed to have. Specifying requirements usually occurs in an early phase of software development, before coding begins. In one example, discovered defects may be managed by the project management application of the software development platform.
Defect tracker 120 may track any defects addressed by change sets tracked by code tracker 110. For example, a developer that commits a change set may indicate that the change set addresses one or more defects being tracked by defect tracker 120. Defect tracker 120 may interface with code tracker 110 to maintain a correlation between the change set and the defects addressed by the change set.
The defect density module 130 may determine a number of defects in a portion of the code base having a particular characteristic. The characteristic may be at least one of an author and a requirement. For example, if the characteristic is an author, then the portion of the code base having the characteristic would be code that was authored by the author. The author may be any of various developers that have authored code in the code base. If the characteristic is a requirement, then the portion of the code base having the characteristic would be code implementing the requirement. Another characteristic that may be considered is a time period during which the code was produced. For example, code generated during the month of March may be considered. Characteristics may be combined as well, such that the portion of the code base may have all of the combined characteristics. For instance, the portion of the code base may include code authored by a particular author during a particular time period. In another example, the portion of the code base may include code authored by a particular author that implements a particular requirement.
The defect density module 130 may identify the portion of the code base having the characteristic by requesting from the code tracker 110 code in the code base having the characteristic. The code tracker 110 may provide code having the characteristic whether the code constitutes original code or changes to original code. That is, the portion of the code base having the characteristic may be code authored at any point during the development cycle as long as the code has the specified characteristic. Additionally, the portion of the code base may include non-consecutive lines of code. For example, if the characteristic is a particular author, code authored by the author in a change set that constitutes a modification of existing code may include changes to non-consecutive lines of existing code.
The defect density module 130 may determine the number of defects in the portion of the code base having the characteristic by determining which changes addressing a defect occurred in the portion of the code base having the characteristic. The defect density module 130 may determine this by referring to the defect tracker 120, which maintains a correlation between all committed changes sets that address a defect and the defects addressed by those change sets. An example illustration will be provided with respect to FIG. 3, discussed later.
The number of defects in a portion of the code base may be considered a defect density. Sometimes the defect density may be referred to as a number of defects per number of lines of code. Accordingly, the number of lines of code in the portion of the code base having the characteristic may be determined, so that the defect density may be indicated in such a manner. This will also be discussed in more detail with respect to FIG. 3.
FIG. 2 illustrates a computing system 200 for determining a defect density, according to an example. Computing system 200 may be similar to computing system 100, as described above. Code tracker 210, defect tracker 220, and defect density module 230 may also be similar to the identically named elements in computing system 100. Computing system 200 may also include a user interface 240 and a code base 250. Code base 250 may be a database for storing the code base. Code base 250 may include one or more data storage devices and may be spread across one or more computers, such as server computers. Code base 250 may be managed by the source code management program.
User interface 240 may include hardware components and software components. The hardware components may include input devices (e.g., keyboard, mouse, touch screen, microphone, etc.) and output devices (e.g., a display, a touch display, speakers, etc.). The hardware components may be part of a user's device used to interact with computing system 200. The software components may include one or more graphical user interfaces implemented by the user's device that interface with the user for receiving input and providing output. In some examples, user interface 240 can be considered to include only the software component.
The user interface 240 may interface with other components of computing system 200. Accordingly, for example, user interface 240 may be used to interact with the software development platform and may be a part of the platform. For example, user interface 240 may be an interface for the source code management program, the project management application, or the IDE.
User interface 240 may be used to specify the characteristic(s) for identifying the portion of the code base. For example, the user interface 240 can be used to identify an author, a requirement, or a time period. User interface 240 may also be used to commit change sets to the code base. In particular, user interface 240 may be used to specify one or more defects addressed by a change set or one or more requirements implemented by a change set.
FIG. 3 illustrates a use case in which a defect density can be determined based on multiple characteristics, according to a simplified example. Code development is indicated over the course of a work week. Change sets modifying two classes, Class A and Class B, are shown. Specifically, the large rectangle represents the class as a whole and the shaded rectangles on Monday-Thursday indicate changes to the classes by two different developers, Joe and Flo. Each developer's changes to the classes for a single day may represent changes in a single change set. Alternatively, the changes may have been committed to the code base in separate instances, even on the same day. An example of changes spanning non-consecutive lines of code is shown in Class A on Monday. As can be seen, Joe's committed changes for the day modify different portions of the class.
The shaded rectangles shown in Class A and Class B on Friday indicate modifications to the two classes to correct defects. Note that these modifications themselves represent change sets and that it is possible that new defects could be discovered due to these changes. As can be seen, there are three defects that are corrected on Friday. Defect 1 required modifications to Class A and Class B. Defects 2 and 3 only required modifications to Class B.
As shown by the dotted lines, the code modified to address the defects can be traced back to previous change sets where the code was originally entered or modified. For example, the changes to Classes A and B to address Defect 1 modified code authored by Joe. The changes to Class B to address Defect 2 modified code authored by Flo. The changes to Class B to address Defect 3 modified code authored by Joe. Accordingly, two defects can be attributed to Joe and one defect can be attributed to Flo. Additionally, assuming that Joe and no each authored 1000 lines of code, a defect density for Joe's code can be said to be 2 defects per 1000 lines of code. A defect density for Flo's code can be said to be 1 defect per 1000 lines of code. This information may be presented in graph form and may be useful to identify developers that have a higher rate of defects.
The defect density may also be measured according to other characteristics or combinations of characteristics, as well. For example, a time period may be specified, one or more requirements may be specified, one or more modules of code may be specified, and the like. In this way, trends or patterns in defects may be identified. For example, by specifying both a developer and one or more requirements, it may be determined whether a developer tends to enter more defects depending on the requirement being implemented. This may occur due to the developer having a particular proficiency with one type of programming, such as user interface programming, while having a deficiency with another type of programming, such as database programming. In another example, it may be determined that a developer tends to generate more defects when modifying already existing code versus generating new code.
FIG. 4 illustrates a method of determining a defect density, according to an example. Method 400 may be implemented by a computing system, such as computing system 100 or 200. At 410, changes to a code base may be tracked. For example, a software development platform may be used to track the changes. At 420, a correlation between defects and changes addressing the defects may be maintained. At 430, a first defect density in a first subset or portion of a code base having a characteristic may be determined. The characteristic may be an author or a requirement. The defect density may be determined by identifying changes addressing defects that modify the subset or portion of the code base.
FIG. 5 illustrates a method of determining a second defect density and displaying the results, according to an example. Method 500 may be implemented by a computing system, such as computing system 100 or 200. At 510, a second defect density in a second subset or portion of the code base may be determined. For example, the second subset of portion of the code base may have a characteristic different from the characteristic of the first subset or portion of the code base. In one example, the characteristic of the first subset of the code base may be a first author and the characteristic of the second subset of the code base may be a second author. The second defect density may be determined by identifying changes addressing defects that modify the second subset of the code base. At 520, a graph may be displayed comparing the first defect density and the second defect density.
FIG. 6 illustrates a computer-readable medium for determining a defect density, according to an example. Computer 600 may be any of a variety of computing devices or systems, such as described with respect to computing system 100 or 200.
Processor 610 may be at least one central processing unit (CPU), at least one semiconductor-based microprocessor, other hardware devices or processing elements suitable to retrieve and execute instructions stored in machine-readable storage medium 620, or combinations thereof. Processor 610 can include single or multiple cores on a chip, multiple cores across multiple chips, multiple cores across multiple devices, or combinations thereof. Processor 610 may fetch, decode, and execute instructions 622, 624, 626, among others, to implement various processing. As an alternative or in addition to retrieving and executing instructions, processor 610 may include at least one integrated circuit (IC), other control logic, other electronic circuits, or combinations thereof that include a number of electronic components for performing the functionality of instructions 622, 624, 626. Accordingly, processor 610 may be implemented across multiple processing units and instructions 622, 624, 626 may be implemented by different processing units in different areas of computer 600.
Machine-readable storage medium 620 may be any electronic, magnetic, optical, or other physical storage device that contains or stores executable instructions. Thus, the machine-readable storage medium may comprise, for example, various Random Access Memory (RAM), Read Only Memory (ROM), flash memory, and combinations thereof. For example, the machine-readable medium may include a Non-Volatile Random Access Memory (NVRAM), an Electrically Erasable Programmable Read-Only Memory (EEPROM), a storage drive, a NAND flash memory, and the like. Further, the machine-readable storage medium 620 can be computer-readable and non-transitory. Machine-readable storage medium 620 may be encoded with a series of executable instructions for managing processing elements.
The instructions 622, 624, 626, when executed by processor 610 (e.g., via one processing element or multiple processing elements of the processor) can cause processor 610 to perform processes, for example, the processes depicted in FIGS. 4 and 5. Furthermore, computer 600 may be similar to computing systems 100 or 200 and may have similar functionality and be used in similar ways, as described above.
Code tracking instructions 622 can cause processor 610 to track additions and changes to source code having multiple authors. Each addition and change may indicate the respective author. In one example, a software development platform may be used to track this information. Defect tracking instructions 624 can cause processor 610 to track defects addressed by the changes. Defect density instructions 626 can cause processor 610 to determine a defect density in a portion of the source code authored by a first author by identifying changes that modify the portion of the source code authored by the first author and that address a defect.

## Claims

1. A computing system, comprising:
a code tracker to track changes to a code base, wherein the changes are authored by a first author;
a defect tracker to track defects in the code base and to maintain a correlation between the changes and the defects addressed by the changes; and
a defect density module to determine a number of defects in a portion of the code base authored by a second author by determining how many defects are addressed by changes occurring in the portion of the code base.

2. The computing system of claim 1, comprising a user interface to specify the second author.

3. The computing system of claim 2, wherein the user interface is configured to specify a time period, the portion of the code base being limited to code authored by the second author during the time period.

4. The computing system of claim 1, wherein the defect density module is configured to identify the portion of the code base by requesting from the code tracker code in the code base authored by the second author.

5. The computing system of claim 4, wherein the code tracker is configured to provide to the defect density module code whether the code is original code added to the code base or changes to the original code.

6. The computing system of claim 1, wherein the portion of the code base comprises non-consecutive lines of code.

7. The computing system of claim 1, wherein the defect density indicates a number of defects per unit of program code for the second author.

8. A method, comprising:
tracking changes to a code base using a source code management application, wherein the changes are authored by a first author;
maintaining a correlation between defects in the code base and changes addressing the defects; and
determining a defect density in a subset of the code base authored by a second author by identifying how many defects are addressed by changes that modify the subset of the code base.

9. The method of claim 8, further comprising:
determining a second defect density in a second subset of the code base by identifying how many defects are addressed by changes that modify the second subset of the code base; and
displaying a graph comparing the defect density and the second defect density.

10. The method of claim 9, wherein the second subset of the code base constitutes code authored by a third author and that implements a development requirement.

11. The method of claim 10, wherein the defect density indicates a proficiency of the third author with the development requirement.

12. The method of claim 10, wherein the development requirement is at least one of a feature, property, and functionality that the code base is supposed to have.

13. The method of claim 8, further comprising receiving specification of the second author via a user interface.

14. The method of claim 13, wherein the second author is one of multiple developers that authored code in the code base.

15. The method of claim 8, further comprising identifying a trend in the defects based at least in part on the defect density.

16. A non-transitory computer-readable storage medium comprising instructions that, when executed by a processor, cause the processor to:
track changes to source code having multiple authors, wherein the changes are authored by a first author;
track defects addressed by the changes; and
determine a defect density in a portion of the source code authored by a second author by identifying changes that modify the portion of the source code authored by the second author and that address a defect.

17. The computer-readable medium of claim 16, the storage medium storing instructions that, when executed by a processor, cause the processor to maintain a correlation between change sets that address a defect and defects addressed by the change sets.

18. The computer-readable medium of claim 16, wherein the portion of the source code authored by the second author includes a line of code authored by another author when it was added to the source code but was authored by the second author in a subsequent change.