proposition rule for nil branch

this pull request propose a potential rule that check methods have not nil branch useless. #16515

src/General-Rules-Tests/ReNilBranchRuleTest.class.st

@@ -0,0 +1,46 @@
+Class {
+	#name : 'ReNilBranchRuleTest',
+	#superclass : 'ReAbstractRuleTestCase',
+	#category : 'General-Rules-Tests-Migrated',
+	#package : 'General-Rules-Tests',
+	#tag : 'Migrated'
+}
+
+{ #category : 'tests' }
+ReNilBranchRuleTest >> testRuleNotViolated [
+
+	| critiques |
+	self class
+		compile: 'method 1 < 0 ifTrue: [ 1 ]'
+		classified: 'test-helper'.
+	[
+	critiques := self myCritiquesOnMethod: self class >> #method.
+	self assertEmpty: critiques ] ensure: [
+		(self class >> #method) removeFromSystem ]
+]
+
+{ #category : 'tests' }
+ReNilBranchRuleTest >> testRuleWithIfFalse [
+
+	| critiques |
+	self class
+		compile: 'method 1 < 0 ifFalse: [ 1 ] ifTrue: [ nil ]'
+		classified: 'test-helper'.
+	[
+	critiques := self myCritiquesOnMethod: self class >> #method.
+	self assert: critiques size equals: 1 ] ensure: [
+		(self class >> #method) removeFromSystem ]
+]
+
+{ #category : 'tests' }
+ReNilBranchRuleTest >> testRuleWithIfTrue [
+
+	| critiques |
+	self class
+		compile: 'method 1 < 0 ifTrue: [ 1 ] ifFalse: [ nil ]'
+		classified: 'test-helper'.
+	[
+	critiques := self myCritiquesOnMethod: self class >> #method.
+	self assert: critiques size equals: 1 ] ensure: [
+		(self class >> #method) removeFromSystem ]
+]

src/General-Rules/ReNilBranchRule.class.st

@@ -0,0 +1,32 @@
+"
+this smell arise when a branch nil useless is detected.
+"
+Class {
+	#name : 'ReNilBranchRule',
+	#superclass : 'ReNodeRewriteRule',
+	#category : 'General-Rules-Migrated',
+	#package : 'General-Rules',
+	#tag : 'Migrated'
+}
+
+{ #category : 'accessing' }
+ReNilBranchRule >> group [
+
+	^ 'Design Flaws'
+]
+
+{ #category : 'initialization' }
+ReNilBranchRule >> initialize [
+
+	super initialize
+		replace: '`@condition ifTrue: [ `@.statements] ifFalse: [ nil ]'
+		with: '`@condition ifTrue: [ `@.statements]';
+		replace: '`@condition ifFalse: [ `@.statements] ifTrue: [ nil ]'
+		with: '`@condition ifFalse: [ `@.statements]'
+]
+
+{ #category : 'accessing' }
+ReNilBranchRule >> name [ 
+
+	^ 'branch nil is useless'
+]