Add test covering methods for "is*ForNewerJava()"

This way at least we know the backend methods should not be broken without
noticing.

test/src/test/java/hudson/model/UpdateSiteTest.java

@@ -153,6 +153,31 @@ public class UpdateSiteTest {
         assertNotEquals("plugin data is present", Collections.emptyMap(), site.getData().plugins);
     }
 
+    @Test public void minimumJavaVersion() throws Exception {
+        // TODO: factor out the sites init
+        PersistedList<UpdateSite> sites = j.jenkins.getUpdateCenter().getSites();
+        sites.clear();
+        URL url = new URL(baseUrl, "/plugins/minJavaVersion-update-center.json");
+        UpdateSite site = new UpdateSite(UpdateCenter.ID_DEFAULT, url.toString());
+        sites.add(site);
+        assertEquals(FormValidation.ok(), site.updateDirectly(false).get());
+        // END TODO
+
+        final UpdateSite.Plugin tasksPlugin = site.getPlugin("tasks");
+        assertNotNull(tasksPlugin);
+        assertFalse(tasksPlugin.isNeededDependenciesForNewerJava());
+        assertFalse(tasksPlugin.isForNewerJava());
+
+        final UpdateSite.Plugin pluginCompiledForTooRecentJava = site.getPlugin("java-too-recent");
+        assertFalse(pluginCompiledForTooRecentJava.isNeededDependenciesForNewerJava());
+        assertTrue(pluginCompiledForTooRecentJava.isForNewerJava());
+
+        final UpdateSite.Plugin pluginDependingOnPluginCompiledForTooRecentJava = site.getPlugin("depending-on-too-recent-java");
+        assertTrue(pluginDependingOnPluginCompiledForTooRecentJava.isNeededDependenciesForNewerJava());
+        assertFalse(pluginDependingOnPluginCompiledForTooRecentJava.isForNewerJava());
+
+    }
+
     @Issue("JENKINS-31448")
     @Test public void isLegacyDefault() throws Exception {
         assertFalse("isLegacyDefault should be false with null id",new UpdateSite(null,"url").isLegacyDefault());

test/src/test/resources/plugins/minJavaVersion-update-center.json

+updateCenter.post(
+{"connectionCheckUrl":"http://www.google.com/", // has to be here because updateDirectly sniffs only very limited formats
+    "core": {
+        "buildDate": "Dec 31, 1969",
+        "name": "core",
+        "url": "jenkins.war",
+        "version": "23"
+    },
+    "id": "default",
+    "plugins": {
+        "tasks": {
+            "buildDate": "Dec 17, 2008",
+            "dependencies": [],
+            "developers": [{"name": "lokadm"}],
+            "excerpt": "   This plug-in scans for open tasks in a specified set of files in the project modules   and visualizes the results.  ",
+            "name": "tasks",
+            "requiredCore": "1.264",
+            "sha1": "wtzlciUKiMcg90H5CTYkGX6+r8Y=",
+            "title": "Jenkins Task Scanner Plug-in",
+            "url": "tasks.jpi",
+            "version": "2.23"
+        },
+        "java-too-recent": {
+            "buildDate": "Dec 17, 2008",
+            "dependencies": [],
+            "developers": [],
+            "excerpt": "…",
+            "name": "dummy",
+            "requiredCore": "1.100",
+            "sha1": "wtzlcjUKiMcg90H5CTYkGX6+r8Y=",
+            "title": "Dummy",
+            "url": "http://nowhere.net/dummy.hpi",
+            "version": "1.0",
+            "minimumJavaVersion": "25"
+        },
+        "depending-on-too-recent-java": {
+            "buildDate": "Dec 17, 2008",
+            "dependencies": [
+                {
+                    "name": "java-too-recent",
+                    "optional": false,
+                    "version":"1.0"
+                }
+            ],
+            "developers": [{"name": "lokadm"}],
+            "excerpt": "   This plug-in scans for open tasks in a specified set of files in the project modules   and visualizes the results.  ",
+            "name": "tasks",
+            "requiredCore": "1.264",
+            "sha1": "wtzlciUKiMcg90H5CTYkGX6+r8Y=",
+            "title": "Jenkins Task Scanner Plug-in",
+            "url": "tasks.jpi",
+            "version": "2.23"
+        }
+    },
+    "updateCenterVersion": 1
+}
+);