feat: allow to define releaseAssets

Now you can add files to be released to github using the extension:

```groovy
apply plugin: 'java'
task sourcesJar(type: Jar) {
    classifier = 'sources'
    from sourceSets.main.allSource
}
semanticRelease {
    changeLog {
        releaseAssets(jar, sourcesJar)
    }
}
```


Closes #13

README.md

@@ -135,11 +135,14 @@ semanticRelease {
 The **ghToken** is mandatory.
 
 ```groovy
+apply plugin: 'java'
+task sourcesJar(type: Jar) {
+    classifier = 'sources'
+    from sourceSets.main.allSource
+}
 semanticRelease {
     changeLog {
-        releaseAsset = { ReleaseAssets assets, String currentTag ->
-            assets.upload(file("build/libs/value-${currentTag}.jar").bytes, "application/zip", "run-${currentTag}.jar")
-        }
+        releaseAssets(jar, sourcesJar)
     }
 }
 ```

src/main/groovy/de/gliderpilot/gradle/semanticrelease/SemanticReleaseChangeLogService.groovy

@@ -43,10 +43,14 @@ class SemanticReleaseChangeLogService {
 
     @PackageScope
     Github github
+    private Closure<Iterable<File>> files
+    private Iterable<File> releaseAssets
 
-    SemanticReleaseChangeLogService(Grgit grgit, TagStrategy tagStrategy) {
+    SemanticReleaseChangeLogService(Grgit grgit, TagStrategy tagStrategy, Closure<Iterable<File>> files) {
         this.grgit = grgit
         this.tagStrategy = tagStrategy
+        this.files = files
+        releaseAssets = files()
     }
 
     void setGhToken(String token) {
@@ -207,9 +211,8 @@ class SemanticReleaseChangeLogService {
         repositoryUrl("compare/${previousTag}...${currentTag}")
     }
 
-    @PackageScope
-    def releaseAsset = { ReleaseAssets assets, String currentTag ->
-        // waiting the custom implementation
+    void releaseAssets(Object... assets) {
+        releaseAssets += files(assets)
     }
 
     @PackageScope
@@ -243,7 +246,9 @@ class SemanticReleaseChangeLogService {
 
         Release release = repo.releases().create(tag)
         new Release.Smart(release).body(changeLog(commits(Version.valueOf(version.previousVersion)), version).toString())
-        releaseAsset(release.assets(), "$version.version")
+        releaseAssets.each {
+            release.assets().upload(it.bytes, URLConnection.guessContentTypeFromName(it.name) ?: "application/octet-stream", it.name)
+        }
     }
 
     private boolean tagExists(Repo repo, String tag) {

src/main/groovy/de/gliderpilot/gradle/semanticrelease/SemanticReleasePluginExtension.groovy

@@ -39,7 +39,7 @@ class SemanticReleasePluginExtension {
     @Inject
     SemanticReleasePluginExtension(Project project) {
         this.project = project
-        changeLog = new SemanticReleaseChangeLogService(project.grgit, project.release.tagStrategy)
+        changeLog = new SemanticReleaseChangeLogService(project.grgit, project.release.tagStrategy, project.&files)
         releaseBranches = new SemanticReleaseCheckBranch()
         branchNames = new SemanticReleaseAppendBranchNameStrategy(releaseBranches)
         semanticStrategy = new SemanticReleaseNormalStrategy(project.grgit, changeLog)

src/test/groovy/de/gliderpilot/gradle/semanticrelease/SemanticReleaseChangeLogServiceSpec.groovy

@@ -39,8 +39,10 @@ class SemanticReleaseChangeLogServiceSpec extends Specification {
     Grgit grgit = Mock()
     TagStrategy tagStrategy = new TagStrategy()
 
+    Closure<Iterable<File>> files = { it instanceof Object[] ? it as List : [] }
+
     @Subject
-    SemanticReleaseChangeLogService changeLogService = new SemanticReleaseChangeLogService(grgit, tagStrategy)
+    SemanticReleaseChangeLogService changeLogService = new SemanticReleaseChangeLogService(grgit, tagStrategy, files)
 
     def "does not throw an exception if no ticket is referenced"() {
         given:
@@ -179,7 +181,7 @@ class SemanticReleaseChangeLogServiceSpec extends Specification {
     def "changeLog is generated"() {
         given:
         grgit = Grgit.open()
-        changeLogService = new SemanticReleaseChangeLogService(grgit, tagStrategy)
+        changeLogService = new SemanticReleaseChangeLogService(grgit, tagStrategy, files)
         String mnemo = changeLogService.mnemo()
 
         when:
@@ -220,7 +222,9 @@ class SemanticReleaseChangeLogServiceSpec extends Specification {
     def "change log is uploaded to GitHub"() {
         given:
         grgit = Grgit.open()
-        changeLogService = new SemanticReleaseChangeLogService(grgit, tagStrategy)
+        changeLogService = new SemanticReleaseChangeLogService(grgit, tagStrategy, files)
+        File asset = new File('settings.gradle')
+        changeLogService.releaseAssets(asset)
         String mnemo = changeLogService.mnemo()
         String user = mnemo.substring(0, mnemo.indexOf("/"))
         String repo = mnemo.substring(mnemo.indexOf("/") + 1)
@@ -241,12 +245,13 @@ class SemanticReleaseChangeLogServiceSpec extends Specification {
 
         then:
         release?.body() == 'changelog'
+        release?.assets().iterate().any { it.json().getString("name") == asset.name }
     }
 
     def "change log is not uploaded to GitHub when no gh token is set"() {
         given:
         grgit = Grgit.open()
-        changeLogService = new SemanticReleaseChangeLogService(grgit, tagStrategy)
+        changeLogService = new SemanticReleaseChangeLogService(grgit, tagStrategy, files)
 
         when:
         changeLogService.createGitHubVersion(new ReleaseVersion(previousVersion: '1.0.0', version: '1.0.1'))

src/test/groovy/de/gliderpilot/gradle/semanticrelease/SemanticReleaseNormalStrategySpec.groovy

@@ -29,7 +29,7 @@ class SemanticReleaseNormalStrategySpec extends Specification {
 
     Grgit grgit = Mock()
     TagStrategy tagStrategy = new TagStrategy()
-    SemanticReleaseChangeLogService changeLogService = new SemanticReleaseChangeLogService(grgit, tagStrategy)
+    SemanticReleaseChangeLogService changeLogService = new SemanticReleaseChangeLogService(grgit, tagStrategy, { [] })
 
     @Subject
     SemanticReleaseNormalStrategy strategy = new SemanticReleaseNormalStrategy(grgit,

src/test/groovy/de/gliderpilot/gradle/semanticrelease/SemanticReleasePluginSpec.groovy

@@ -166,4 +166,19 @@ class SemanticReleasePluginSpec extends ProjectSpec {
         project.tasks.release.finalizedBy.getDependencies(project.tasks.release).contains(project.tasks.uploadArchives)
     }
 
+    def "can define releaseAssets"() {
+        when:
+        project.with {
+            apply plugin: PLUGIN
+            apply plugin: 'java'
+            semanticRelease {
+                changeLog {
+                    releaseAssets jar
+                }
+            }
+        }
+
+        then:
+        project.semanticRelease.changeLog.releaseAssets.toList().containsAll(project.jar.outputs.files.files)
+    }
 }