Avoid IS INSTANCE OF and CASE TYPE OF Type Tests

WarningClean ABAP & Modern Syntax#EC NO_INSTANCE_OFRemote Enabled

Overview

Avoid IS INSTANCE OF / CASE TYPE OF checks.

ATC Finding Message: Avoid runtime type checks via IS INSTANCE OF; use polymorphism

Rationale

Checking concrete object types at runtime via IS INSTANCE OF or CASE TYPE OF breaks polymorphism, violates the Open-Closed Principle, and introduces fragile type coupling. Instead of conditional type inspection, introduce polymorphic methods on common interfaces.

Non-Compliant

IF io_shape IS INSTANCE OF cl_circle.
  render_circle( ).
ENDIF.

Compliant

io_shape->render( ).

Configuration & Thresholds

This check can be fine-tuned directly in the ATC Check Variant Editor (CHKV) in Eclipse ADT:

Parameter Name	Data Type	Default Value	Description & Guidance
CHECK_CASE_TYPE	Boolean	true	Report CASE TYPE OF type tests in addition to IS INSTANCE OF

Suppression

To suppress findings for this rule, append the pseudo-comment to the statement:

" Standard pseudo-comment:
... "#EC NO_INSTANCE_OF

" SAP CI_ prefix format:
... "#EC CI_NO_INSTANCE_OF

Related Rules

• Avoid Calling Static Methods via Instance References (->) — #EC NO_STATIC_ARROW
• Avoid Exposed Mutable Data in Classes and Interfaces — #EC PUBLIC_ATTR
• Prefer NEW #( ) over CREATE OBJECT — #EC PREF_NEW_OPERATOR

Technical Details

• Native ATC Class: ZCL_SKYLINT_NO_INSTANCE_OF
• Implementation File: zcl_skylint_no_instance_of.clas.abap