CA1069.md

Pattern: Duplicate enum value

Issue: -

Description

Every enum member should either have a unique constant value or be explicitly assigned with a prior member in the enum to indicate explicit intent of sharing value.

This rule helps in catching functional bugs introduced from the following scenarios:

• Accidental typing mistakes, where the user accidentally typed the same constant value for multiple members.
• Copy paste mistakes, where the user copied an existing member definition, then renamed the member but forgot to change the value.
• Merge resolution from multiple branches, where a new member was added with a different name but the same value in different branches.

Example of incorrect code:

enum TestEnum
{
   Field1 = 1,
   AnotherNameForField1 = Field1,   // This is fine
   Field2 = 2,
   Field3 = 2,   // CA1069: This is not fine.
}

Example of correct code:

enum TestEnum
{
   Field1 = 1,
   AnotherNameForField1 = Field1,   // This is fine
   Field2 = 2,
   Field3 = Field2,   // This is also fine
}

Further Reading

• CA1069