Add tests on extensions.

Fixes #24

src/Chanel-Tests/ChanelAbstractCleanerTest.class.st

@@ -13,6 +13,16 @@ Class {
 	#category : #'Chanel-Tests'
 }
 
+{ #category : #testing }
+ChanelAbstractCleanerTest class >> isAbstract [
+	^ self = ChanelAbstractCleanerTest
+]
+
+{ #category : #testing }
+ChanelAbstractCleanerTest class >> shouldInheritSelectors [
+	^ true
+]
+
 { #category : #accessing }
 ChanelAbstractCleanerTest >> actualClass [
 	^ self class environment at: (self class name withoutSuffix: 'Test') asSymbol

src/Chanel-Tests/ChanelConditionalSimplifierCleanerTest.class.st

@@ -53,6 +53,25 @@ ChanelConditionalSimplifierCleanerTest >> testIsNotNilIfTrueIfFalse [
 	self assert: '10 isNotNil ifTrue: [ false ] ifFalse: [ true ]' isRewrittenAs: '10 ifNil: [ true ] ifNotNil: [ false ]'
 ]
 
+{ #category : #tests }
+ChanelConditionalSimplifierCleanerTest >> testReplacementDoesNotRemoveExtensions [
+	class
+		compile:
+			('{1}
+  {2}' format: {self selector . '10 isNil ifFalse: [ false ]'})
+		classified: self extensionProtocol.
+
+	self runCleaner.
+
+	self
+		assert: (class >> self selector) sourceCode
+		equals:
+			('{1}
+  {2}' format: {self selector . '10 ifNotNil: [ false ]'}).
+
+	self assert: (class >> self selector) protocol equals: self extensionProtocol
+]
+
 { #category : #tests }
 ChanelConditionalSimplifierCleanerTest >> testReplacementOnClassSide [
 	class class

src/Chanel-Tests/ChanelTestEqualityCleanerTest.class.st

@@ -73,6 +73,25 @@ ChanelTestEqualityCleanerTest >> testDenyIdenticalTo [
 	self assert: 'self deny: 3 == 2' isRewrittenAs: 'self deny: 3 identicalTo: 2'
 ]
 
+{ #category : #tests }
+ChanelTestEqualityCleanerTest >> testDoesNotRemoveExtensions [
+	class
+		compile:
+			('{1}
+  {2}' format: {self selector . 'self assert: 3 = 2'})
+		classified: self extensionProtocol.
+
+	self runCleaner.
+
+	self
+		assert: (class >> self selector) sourceCode
+		equals:
+			('{1}
+  {2}' format: {self selector . 'self assert: 3 equals: 2'}).
+
+	self assert: (class >> self selector) protocol equals: self extensionProtocol
+]
+
 { #category : #tests }
 ChanelTestEqualityCleanerTest >> testReplacementOnClassSide [
 	class class