Mojo: validate nullability in Java serialization.

mojo/android/javatests/src/org/chromium/mojo/bindings/SerializationTest.java

Index: mojo/android/javatests/src/org/chromium/mojo/bindings/SerializationTest.java
diff --git a/mojo/android/javatests/src/org/chromium/mojo/bindings/SerializationTest.java b/mojo/android/javatests/src/org/chromium/mojo/bindings/SerializationTest.java
new file mode 100644
index 0000000000000000000000000000000000000000..9f7e94bdfc28bd954511743c9598f8187dd52a05
--- /dev/null
+++ b/mojo/android/javatests/src/org/chromium/mojo/bindings/SerializationTest.java
@@ -0,0 +1,132 @@
+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+package org.chromium.mojo.bindings;
+
+import android.test.suitebuilder.annotation.SmallTest;
+
+import junit.framework.TestCase;
+
+import org.chromium.mojo.HandleMock;
+import org.chromium.mojo.bindings.test.mojom.mojo.Struct1;
+import org.chromium.mojo.bindings.test.mojom.mojo.Struct2;
+import org.chromium.mojo.bindings.test.mojom.mojo.Struct3;
+import org.chromium.mojo.bindings.test.mojom.mojo.Struct4;
+import org.chromium.mojo.bindings.test.mojom.mojo.Struct5;
+import org.chromium.mojo.bindings.test.mojom.mojo.Struct6;
+import org.chromium.mojo.bindings.test.mojom.mojo.StructOfNullables;
+
+/**
+ * Tests for the serialization logic of the generated structs, using structs defined in
+ * mojo/public/interfaces/bindings/tests/serialization_test_structs.mojom .
+ */
+public class SerializationTest extends TestCase {
+
+    private static void assertThrowsException(Struct struct) {
+        boolean exceptionThrown = false;
+        try {
+            struct.serialize(null);
+        } catch (SerializationException ex) {
+            exceptionThrown = true;
+        }
+        assertTrue(exceptionThrown);

[qsr, 2014/09/03 07:56:28]

Instead of this, you can do:

try {
    struct.serialize(null);
    fail("Serialization should have thrown an exception.");
} catch (SerializationException ex) {
    // Expected.
}

[ppi, 2014/09/03 08:53:46]

Done.

+    }
+
+    /**
+     * Verifies that serializing a struct with an invalid handle of a non-nullable type throws an
+     * exception.
+     */
+    @SmallTest
+    public void testHandle() {
+        Struct2 struct = new Struct2();
+        assertFalse(struct.hdl.isValid());
+        assertThrowsException(struct);
+
+        // Make the struct valid and verify that it serializes without an exception.
+        struct.hdl = new HandleMock();
+        struct.serialize(null);
+    }
+
+    /**
+     * Verifies that serializing a struct with a null struct pointer throws an exception.
+     */
+    @SmallTest
+    public void testStructPointer() {
+        Struct3 struct = new Struct3();
+        assertNull(struct.struct1);
+        assertThrowsException(struct);
+
+        // Make the struct valid and verify that it serializes without an exception.
+        struct.struct1 = new Struct1();
+        struct.serialize(null);
+    }
+
+    /**
+     * Verifies that serializing a struct with an array of structs throws an exception when the
+     * struct is invalid.
+     */
+    @SmallTest
+    public void testStructArray() {
+        Struct4 struct = new Struct4();
+        assertNull(struct.array);
+        assertThrowsException(struct);
+
+        // Create the (1-element) array but have the element null.
+        struct.array = new Struct1[1];
+        assertThrowsException(struct);
+
+        // Create the array element, struct should serialize now.
+        struct.array[0] = new Struct1();
+        struct.serialize(null);
+    }
+
+    /**
+     * Verifies that serializing a struct with a fixed-size array of incorrect length throws an
+     * exception.
+     */
+    @SmallTest
+    public void testFixedSizeArray() {
+        Struct5 struct = new Struct5();
+        assertNull(struct.pair);
+        assertThrowsException(struct);
+
+        // Create the (1-element) array, 2-element array is required.
+        struct.pair = new Struct1[1];
+        struct.pair[0] = new Struct1();
+        assertThrowsException(struct);
+
+        // Create the array of a correct size, struct should serialize now.
+        struct.pair = new Struct1[2];
+        struct.pair[0] = new Struct1();
+        struct.pair[1] = new Struct1();
+        struct.serialize(null);
+    }
+
+    /**
+     * Verifies that serializing a struct with a null string throws an exception.
+     */
+    @SmallTest
+    public void testString() {
+        Struct6 struct = new Struct6();
+        assertNull(struct.str);
+        assertThrowsException(struct);
+
+        // Make the struct valid and verify that it serializes without an exception.
+        struct.str = new String();

[qsr, 2014/09/03 07:56:28]

= "" instead?

[ppi, 2014/09/03 08:53:45]

Done.

+        struct.serialize(null);
+    }
+
+    /**
+     * Verifies that a struct with an invalid nullable handle and a null nullable pointer serializes

[qsr, 2014/09/03 07:56:28]

nit: There is more than one null nullable pointer

[ppi, 2014/09/03 08:53:46]

Done.

+     * without an exception.
+     */
+    @SmallTest
+    public void testNullableFields() {
+        StructOfNullables struct = new StructOfNullables();
+        assertFalse(struct.hdl.isValid());
+        assertNull(struct.struct1);
+        assertNull(struct.str);
+        struct.serialize(null);
+    }
+}