Factor out recurring pattern of MD5 checksum + stamp file

.gitignore

@@ -1,3 +1,4 @@
+**/.gradle/
 *.DS_Store
 *.class
 *.out
@@ -10,7 +11,6 @@
 .metadata/
 .project
 /*/.settings/org.eclipse.buildship.core.prefs
-/.gradle/
 /.settings/org.eclipse.buildship.core.prefs
 /build/
 com.ibm.wala.cast.java.jdt.test/

build.gradle

@@ -5,7 +5,7 @@
 
 plugins {
 	id 'com.github.hauner.jarTest' version '1.0.1' apply false
-	id 'de.undercouch.download' version '3.3.0' apply false
+	id 'de.undercouch.download' apply false
 	id 'nebula.lint' version '8.3.1'
 }
 

buildSrc/build.gradle

@@ -0,0 +1,7 @@
+repositories {
+	mavenCentral()
+}
+
+dependencies {
+	compile 'de.undercouch:gradle-download-task:3.3.0'
+}

buildSrc/src/main/groovy/stamp.groovy

@@ -0,0 +1,12 @@
+////////////////////////////////////////////////////////////////////////
+//
+//  helper task for checksum-verified downloads
+//
+
+class VerifyWithStamp extends de.undercouch.gradle.tasks.download.Verify {
+	VerifyWithStamp() {
+		def stamp = new File(temporaryDir, 'stamp')
+		outputs.file stamp
+		doLast { stamp.text = '' }
+	}
+}

com.ibm.wala.cast.java.test.data/build.gradle

@@ -17,13 +17,9 @@ task downloadJLex(type: Download) {
 	overwrite false
 }
 
-task verifyJLex(type: Verify, dependsOn: downloadJLex) {
-	// TODO: refactor this logic into a reusable custom task class
+task verifyJLex(type: VerifyWithStamp, dependsOn: downloadJLex) {
 	src downloadJLex.dest
 	checksum 'fe0cff5db3e2f0f5d67a153cf6c783af'
-	def stamp = new File(temporaryDir, 'stamp')
-	outputs.file stamp
-	doLast { stamp.text = '' }
 }
 
 clean {

com.ibm.wala.cast.js.test.data/build.gradle

@@ -12,13 +12,9 @@ task downloadAjaxslt(type: Download) {
 	overwrite false
 }
 
-task verifyAjaxslt(type: Verify, dependsOn: downloadAjaxslt) {
-	// TODO: refactor this logic into a reusable custom task class
+task verifyAjaxslt(type: VerifyWithStamp, dependsOn: downloadAjaxslt) {
 	src files(downloadAjaxslt)[0]
 	checksum 'c995abe3310a401bb4db7f28a6409756'
-	def stamp = new File(temporaryDir, 'stamp')
-	outputs.file stamp
-	doLast { stamp.text = '' }
 }
 
 task unpackAjaxslt(type: Sync, dependsOn: verifyAjaxslt) {

com.ibm.wala.core.testdata/build.gradle

@@ -27,13 +27,9 @@ task downloadBcel(type: Download) {
 	overwrite false
 }
 
-task verifyBcel(type: Verify, dependsOn: downloadBcel) {
-	// TODO: refactor this logic into a reusable custom task class
+task verifyBcel(type: VerifyWithStamp, dependsOn: downloadBcel) {
 	src files(downloadBcel)[0]
 	checksum '19bffd7f217b0eae415f1ef87af2f0bc'
-	def stamp = new File(temporaryDir, 'stamp')
-	outputs.file stamp
-	doLast { stamp.text = '' }
 }
 
 task extractBcel(type: Sync, dependsOn: verifyBcel) {
@@ -63,13 +59,9 @@ task downloadJavaCup(type: Download) {
 	clean { delete downloadJavaCup }
 }
 
-task verifyJavaCup(type: Verify, dependsOn: downloadJavaCup) {
-	// TODO: refactor this logic into a reusable custom task class
+task verifyJavaCup(type: VerifyWithStamp, dependsOn: downloadJavaCup) {
 	src files(downloadJavaCup)[0]
 	checksum '2bda8c40abd0cbc295d3038643d6e4ec'
-	def stamp = new File(temporaryDir, 'stamp')
-	outputs.file stamp
-	doLast { stamp.text = '' }
 }
 
 extraBundledJars.dependsOn verifyJavaCup
@@ -106,13 +98,9 @@ task downloadOcamlJava(type: Download) {
 	overwrite false
 }
 
-task verifyOcamlJava(type: Verify, dependsOn: downloadOcamlJava) {
-	// TODO: refactor this logic into a reusable custom task class
+task verifyOcamlJava(type: VerifyWithStamp, dependsOn: downloadOcamlJava) {
 	src downloadOcamlJava.outputFiles[0]
 	checksum '45feec6e3889f5073a39c2c4c84878d1'
-	def stamp = new File(temporaryDir, 'stamp')
-	outputs.file stamp
-	doLast { stamp.text = '' }
 }
 
 task unpackOcamlJava(type: Sync, dependsOn: verifyOcamlJava) {