Implement Options.RequestIdOption.(equals, hashCode)

Author: odeke-em

google-cloud-spanner/src/main/java/com/google/cloud/spanner/Options.java

@@ -1088,12 +1088,20 @@ void appendToOptions(Options options) {
 
     @Override
     public int hashCode() {
-      return RequestIdOption.class.hashCode();
+      return this.reqId.hashCode();
     }
 
     @Override
     public boolean equals(Object o) {
-      return o instanceof RequestIdOption;
+      // instanceof for a null object returns false.
+      if (!(o instanceof RequestIdOption)) {
+        return false;
+      }
+      RequestIdOption other = (RequestIdOption) o;
+      if (this.reqId == null || other.reqId == null) {
+        return this.reqId == null && other.reqId == null;
+      }
+      return this.reqId.equals(other.reqId);
     }
   }
 }

google-cloud-spanner/src/test/java/com/google/cloud/spanner/OptionsTest.java

@@ -900,6 +900,22 @@ public void testRequestId() {
     assertThat(option3.toString()).doesNotContain("requestId");
   }
 
+  @Test
+  public void testRequestIdOptionEqualsAndHashCode() {
+    XGoogSpannerRequestId reqId1 = XGoogSpannerRequestId.of(1, 2, 3, 4);
+    XGoogSpannerRequestId reqId2 = XGoogSpannerRequestId.of(2, 3, 4, 5);
+    Options.RequestIdOption opt1 = Options.requestId(reqId1);
+    Options.RequestIdOption opt1Prime = Options.requestId(reqId1);
+    Options.RequestIdOption opt2 = Options.requestId(reqId2);
+
+    assertTrue(opt1.equals(opt1));
+    assertTrue(opt1.equals(opt1Prime));
+    assertEquals(opt1.hashCode(), opt1Prime.hashCode());
+    assertFalse(opt1.equals(opt2));
+    assertNotEquals(opt1, opt2);
+    assertNotEquals(opt1.hashCode(), opt2.hashCode());
+  }
+
   @Test
   public void testOptions_WithMultipleDifferentRequestIds() {
     XGoogSpannerRequestId reqId1 = XGoogSpannerRequestId.of(1, 1, 1, 1);