README.md

A Partial List of Code Smells

Smells and refactorings annotated with [BC] are my (Ben Christel's) original research. In other words, don't expect to find much if you Google them. I've included them here because I think they're relevant for fixing the types of problems represented in autoclop.rb. Other smells are drawn from the C2 Wiki and elsewhere; it's often hard to determine whom to credit.

Unless otherwise noted, all refactorings are from Martin Fowler's book, Refactoring: Improving the Design of Existing Code.

Comments

• Explanatory Comment. Fix using Extract Method combined with Remove Comment [BC], or Replace Inline Code with Function Call.
• Commented-out Code. Fix using Remove Comment [BC].
• Telic Comment in Code. Fix using Move Telic Comment To Test [BC].
• Doc Comment. Fix using Remove Comment [BC].

Spacing

• Inconsistent Formatting. Fix using Rearrange Whitespace [BC].
• Missing Editing Affordance [BC]. Often fixed by Rearrange Whitespace [BC].

Interfaces

• Unclear Name. Fix using Rename Variable, Rename Method.
• Idea Fragment [Katrina Owen]. Fix using Inline Method.
• Data Clump. Fix using Preserve Whole Object or Introduce Parameter Object.
• Alternative Classes with Different Interfaces. Fix using Rename Method.

Procedural Code

• Dead Code. Fix using Remove Dead Code.
• Long Method. Fix with Replace Inline Code with Function Call or Extract Method.
• Nested Loops and Conditionals. Fix with Replace Inline Code with Function Call, Replace Loop with Pipeline, or Extract Method.
• Global State. Fix using Inject Global State [BC]. If code is writing to global state, use Return Modified Value.
• Casual Mutation [BC]. In straight-line code, fix with Split Variable. In looping code, use Replace Loop with Pipeline.
• Asymmetrical Code. Fix with Extract Method, Inline Method, or Rename Method.
• Duplicated Code. Fix by applying the Flocking Rules [Sandi Metz and Katrina Owen].

Objects and Messages

• Null Check. Fix with Introduce Null Object or Introduce Continuation [BC].
• Feature Envy. Fix with Move Method, possibly preceded by Extract Method.
• Primitive Obsession. Fix using Replace Primitive with Object. See also Avoid Hashy Syntax In Ruby for a language-specific refactoring technique.
• Switch on Type. Fix using Replace Conditional with Polymorphism.
• Middleman. Fix using Inline Method.
• Deep Hierarchy [BC]. Flatten deep call trees using Inline Method and Inline Class. Then create shallower trees using Extract Method.
• Message Chain. A.K.A. "Train Wreck" or "Law of Demeter Violation". Fix using Replace Query with Parameter or Extract Method and Move Method.
• Option Parameter [BC]. Fix with Move Statements To Callers.