Add "contents" property to systemserverclasspath_fragment.

Similar to bcp_fragment's contents, this property lists all java library
contributions made by this fragment.

Bug: 180105615
Test: m nothing
Change-Id: Ifb1f54d5db290fffaa31933d15207014bb72d2fb
diff --git a/java/systemserver_classpath_fragment_test.go b/java/systemserver_classpath_fragment_test.go
index 6126d5e..5272f27 100644
--- a/java/systemserver_classpath_fragment_test.go
+++ b/java/systemserver_classpath_fragment_test.go
@@ -20,13 +20,13 @@
 	"android/soong/android"
 )
 
-var prepareForTestWithSystemserverClasspath = android.GroupFixturePreparers(
+var prepareForTestWithSystemServerClasspath = android.GroupFixturePreparers(
 	PrepareForTestWithJavaDefaultModules,
 )
 
-func TestSystemserverClasspathVariant(t *testing.T) {
+func TestPlatformSystemserverClasspathVariant(t *testing.T) {
 	result := android.GroupFixturePreparers(
-		prepareForTestWithSystemserverClasspath,
+		prepareForTestWithSystemServerClasspath,
 		android.FixtureWithRootAndroidBp(`
 			platform_systemserverclasspath {
 				name: "platform-systemserverclasspath",
@@ -38,9 +38,9 @@
 	android.AssertIntEquals(t, "expect 1 variant", 1, len(variants))
 }
 
-func TestSystemserverClasspath_ClasspathFragmentPaths(t *testing.T) {
+func TestPlatformSystemserverClasspath_ClasspathFragmentPaths(t *testing.T) {
 	result := android.GroupFixturePreparers(
-		prepareForTestWithSystemserverClasspath,
+		prepareForTestWithSystemServerClasspath,
 		android.FixtureWithRootAndroidBp(`
 			platform_systemserverclasspath {
 				name: "platform-systemserverclasspath",
@@ -53,9 +53,9 @@
 	android.AssertPathRelativeToTopEquals(t, "install filepath", "out/soong/target/product/test_device/system/etc/classpaths", p.ClasspathFragmentBase.installDirPath)
 }
 
-func TestSystemserverClasspathModule_AndroidMkEntries(t *testing.T) {
+func TestPlatformSystemserverClasspathModule_AndroidMkEntries(t *testing.T) {
 	preparer := android.GroupFixturePreparers(
-		prepareForTestWithSystemserverClasspath,
+		prepareForTestWithSystemServerClasspath,
 		android.FixtureWithRootAndroidBp(`
 			platform_systemserverclasspath {
 				name: "platform-systemserverclasspath",
@@ -95,3 +95,14 @@
 		}
 	})
 }
+
+func TestSystemserverclasspathFragmentWithoutContents(t *testing.T) {
+	prepareForTestWithSystemServerClasspath.
+		ExtendWithErrorHandler(android.FixtureExpectsAtLeastOneErrorMatchingPattern(
+			`\Qempty contents are not allowed\E`)).
+		RunTestWithBp(t, `
+			systemserverclasspath_fragment {
+				name: "systemserverclasspath-fragment",
+			}
+		`)
+}