Handle single-digit twiddle-wakka (#380)

Author: ysb33r

core-plugin/src/integTest/groovy/com/github/jrubygradle/api/core/IvyXmlProxyServerIntegrationSpec.groovy

@@ -188,6 +188,26 @@ class IvyXmlProxyServerIntegrationSpec extends Specification {
         findFiles (~/^asciidoctor-pdf.*\.gem$/).size() == 3
     }
 
+    @Issue('https://github.com/jruby-gradle/jruby-gradle-plugin/issues/380')
+    void 'Resolve transitive which contains a single digit twiddle-wakka'() {
+        setup:
+        withBuildFile '''
+        dependencies {
+            something 'rubygems:asciidoctor-bibtex:0.3.1'
+            something 'rubygems:bibtex-ruby:4.4.7', {
+                force = true
+            }    
+        }
+        '''
+
+        when:
+        build()
+
+        then:
+        findFiles ~/^asciidoctor-bibtex-0.3.1.gem$/
+        findFiles ~/^bibtex-ruby-4.4.7.gem$/
+    }
+
     private List<File> findFiles(Pattern pat) {
         new File(projectDir, 'build/something').listFiles(new FilenameFilter() {
             @Override

core-plugin/src/main/groovy/com/github/jrubygradle/api/gems/GemVersion.groovy

@@ -432,11 +432,21 @@ class GemVersion implements Comparable<GemVersion> {
     private static GemVersion parseTwiddleWakka(String singleRequirement) {
         String base = getVersionFromRequirement(singleRequirement, TWIDDLE_WAKKA)
         List<String> parts = base.tokenize(VERSION_SPLIT)
-        if (1 == parts) {
+        if (1 == parts.size()) {
+            if (base =~ ONLY_DIGITS) {
+                return new GemVersion(
+                    INCLUSIVE,
+                    base,
+                    null,
+                    OPEN_ENDED
+                )
+            }
+
             throw new GemVersionException(
-                "'${singleRequirement}' does not look like a correctly formattedGEM twiddle-wakka requirement"
+                "'${singleRequirement}' does not look like a correctly formatted GEM twiddle-wakka"
             )
         }
+
         String lastNumberPart = parts[0..-2].reverse().find {
             it =~ ONLY_DIGITS
         }