Fixes: #8075

src/Text-Core/RunArray.class.st

@@ -187,6 +187,14 @@ RunArray >> = otherArray [
 		and: [values hasEqualElements: otherArray values]
 ]
 
+{ #category : #adding }
+RunArray >> add: newObject [ 
+	"Include newObject as one of the receiver's elements. Answer newObject. 
+	ArrayedCollections cannot respond to this message."
+
+	^ self addLast: newObject
+]
+
 { #category : #adding }
 RunArray >> add: newObject withOccurrences: anInteger [
 	"Add value as the last element of the receiver, the given number of times"

src/Text-Tests/RunArrayTest.class.st

@@ -12,6 +12,34 @@ RunArrayTest >> testANewRunArrayIsEmpty [
 	self assertEmpty: RunArray new
 ]
 
+{ #category : #'tests - adding' }
+RunArrayTest >> testAdd [
+
+	| run |
+	run := RunArray new. 
+	self assert: run size equals: 0.
+
+	run add: $A.
+	self assert: run size equals: 1.
+	run add: $A.
+	self assert: run size equals: 2.
+	run add: $B.
+	self assert: run size equals: 3.
+]
+
+{ #category : #'tests - adding' }
+RunArrayTest >> testAddAddsAsLastElement [
+
+	| run |
+	run := RunArray new. 
+	self assert: run size equals: 0.
+
+	run add: $A.
+	run add: $A.
+	run add: $B.
+	self assert: (run at: 3) equals: $B
+]
+
 { #category : #'tests - accessing' }
 RunArrayTest >> testAt [