Merge pull request #1628 from astares/22246-Provide-digitSum-in-Integ…

…er--tests 22246 Provide #digitSum in Integer + tests
pharo-project · Jul 13, 2018 · 87fa773 · 87fa773
2 parents 9d83892 + e081a55
commit 87fa773
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diff --git a/src/Kernel-Tests/IntegerTest.class.st b/src/Kernel-Tests/IntegerTest.class.st
@@ -457,6 +457,18 @@ IntegerTest >> testDifferentBases [
 	self assert: -36rZYXWVUTSRQPONMLKJIHGFEDCBA9876543210 equals: -106300512100105327644605138221229898724869759421181854980.
 ]
 
+{ #category : #'tests - other' }
+IntegerTest >> testDigitSum [
+
+	self assert: 1234 digitSum equals: 10
+]
+
+{ #category : #'tests - other' }
+IntegerTest >> testDigitSumOnNegative [
+
+	self assert: -1234 digitSum equals: 10
+]
+
 { #category : #'tests - basic' }
 IntegerTest >> testDigitsAccess [
 

diff --git a/src/Kernel/Integer.class.st b/src/Kernel/Integer.class.st
@@ -951,6 +951,13 @@ Integer >> digitSubtract: arg [
 	^ sum normalize
 ]
 
+{ #category : #accessing }
+Integer >> digitSum [
+    "Returns the digit sum of the receiver"
+
+    ^self abs asString inject: 0 into: [:value :new| value + new digitValue]
+]
+
 { #category : #'truncation and round off' }
 Integer >> floor [ 
 	"Refer to the comment in Number|floor."