Add test to access resource in module via URL

Author: olpaw

substratevm/src/com.oracle.svm.test/src/com/oracle/svm/test/AddExports.java

@@ -0,0 +1,20 @@
+package com.oracle.svm.test;
+
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+/**
+ * Specifies packages concealed in JDK modules used by a test. The mx unit test runner will ensure
+ * the packages are exported to the module containing annotated test class.
+ */
+@Retention(RetentionPolicy.RUNTIME)
+@Target(ElementType.TYPE)
+public @interface AddExports {
+    /**
+     * The qualified name of the concealed package in {@code <module>/<package>} format (e.g.,
+     * "jdk.internal.vm.ci/jdk.vm.ci.code").
+     */
+    String[] value() default "";
+}

substratevm/src/com.oracle.svm.test/src/com/oracle/svm/test/NativeImageResourceFileSystemProviderTest.java

@@ -62,6 +62,7 @@
 
 import com.oracle.svm.core.configure.ResourcesRegistry;
 
+@AddExports("java.base/java.lang")
 public class NativeImageResourceFileSystemProviderTest {
 
     private static final String RESOURCE_DIR = "/resources";
@@ -572,4 +573,19 @@ public void writingFileAttributes() {
         // 3. Closing file system.
         closeFileSystem(fileSystem);
     }
+
+    @Test
+    public void moduleResourceURLAccess() {
+        URL url = Class.class.getResource("uniName.dat");
+        Assert.assertNotNull("URL for resource java.base/java/lang/uniName.dat must not be null", url);
+        try (InputStream in = url.openStream()) {
+            try {
+                Assert.assertNotEquals("uniName.dat does not seem to contain valid data", in.read(), 0);
+            } catch (IOException e) {
+                Assert.fail("IOException in in.read(): " + e.getMessage());
+            }
+        } catch (IOException e) {
+            Assert.fail("IOException in url.openStream(): " + e.getMessage());
+        }
+    }
 }