In computer programming, code smell is any symptom in the source code of a program that possibly indicates a deeper problem. Code smells are usually not bugs—they are not technically incorrect and don't currently prevent the program from functioning. Instead, they indicate weaknesses in design that may be slowing down development or increasing the risk of bugs or failures in the future.
Often the deeper problem hinted by a code smell can be uncovered when the code is subjected to a short feedback cycle where it is refactored in small, controlled steps, and the resulting design is examined to see if there are any further code smells that indicate the need of more refactoring. From the point of view of a programmer charged with performing refactoring, code smells are heuristics to indicate when to refactor, and what specific refactoring techniques to use. Thus, a code smell is a driver for refactoring.
The term appears to have been coined by Kent Beck on WardsWiki in the late 1990s. Usage of the term increased after it was featured in Refactoring: Improving the Design of Existing Code. Code Smell is also a term used by agile programmers.
Determining what is and is not a code smell is often a subjective judgment, and will often vary by language, developer and development methodology. There are tools, such as Checkstyle, PMD and FindBugs for Java, to automatically check for certain kinds of code smells.
Read more about Code Smell: Common Code Smells
Famous quotes containing the words code and/or smell:
“Many people will say to working mothers, in effect, “I don’t think you can have it all.” The phrase for “have it all” is code for “have your cake and eat it too.” What these people really mean is that achievement in the workplace has always come at a price—usually a significant personal price; conversely, women who stayed home with their children were seen as having sacrificed a great deal of their own ambition for their families.”
—Anne C. Weisberg (20th century)
“Sleeping, sleeping,
it is the
thunder of the serpent
drumroll of
the mounting smell of
gas.”
—Denise Levertov (b. 1923)