Couplers

All the smells in this group contribute to excessive coupling between classes or show what happens if coupling is replaced by excessive delegation.

Feature Envy

A method accesses the data of another object more than its own data.

This smell may occur after fields are moved to a data class. If this is the case, you may want to move the operations on data to this class as well.

Treatment

• Move Method

• Extract Method

Inappropriate Intimacy

One class uses the internal fields and methods of another class.

Message Chains

In code you see a series of calls resembling $a->b()->c()->d().

Treatment

• Hide Delegate

• Extract Method

Middle Man

If a class performs only one action, delegating work to another class, why does it exist at all?

Treatment

If most of a method’s classes delegate to another class, Remove Middle Man is in order.