Merge pull request #1851 from bibonix/fix-1168-user-name-null

#1168: handle JSON null in User.Smart#name() and #hasName()

Author: yegor256

src/main/java/com/jcabi/github/User.java

@@ -162,7 +162,8 @@ public URL url() throws IOException {
          */
         public String name() throws IOException {
             final JsonObject json = this.json();
-            if (!json.containsKey("name")) {
+            final String key = "name";
+            if (!json.containsKey(key) || json.isNull(key)) {
                 throw new IllegalStateException(
                     String.format(
                         // @checkstyle LineLength (1 line)
@@ -171,7 +172,7 @@ public String name() throws IOException {
                     )
                 );
             }
-            return json.getString("name");
+            return json.getString(key);
         }
 
         /**
@@ -180,7 +181,9 @@ public String name() throws IOException {
          * @throws IOException If it fails
          */
         public boolean hasName() throws IOException {
-            return this.json().containsKey("name");
+            final JsonObject json = this.json();
+            final String key = "name";
+            return json.containsKey(key) && !json.isNull(key);
         }
 
         /**

src/test/java/com/jcabi/github/RtUserTest.java

@@ -99,6 +99,24 @@ void checksIfHeHasNoName() throws IOException {
         );
     }
 
+    @Test
+    void hasNameReturnsFalseWhenNameIsNull() throws IOException {
+        MatcherAssert.assertThat(
+            "hasName() must return false when 'name' JSON value is null",
+            RtUserTest.userWithNullName().hasName(),
+            Matchers.equalTo(false)
+        );
+    }
+
+    @Test
+    void nameThrowsIllegalStateWhenNameIsNull() throws IOException {
+        Assertions.assertThrows(
+            IllegalStateException.class,
+            RtUserTest.userWithNullName()::name,
+            "name() must throw IllegalStateException when 'name' JSON value is null"
+        );
+    }
+
     @Test
     void describeAsJson() throws IOException {
         final RtUser user = new RtUser(
@@ -422,6 +440,25 @@ void markAsReadErrorIfResponseStatusIsNot205() throws IOException {
         }
     }
 
+    /**
+     * Return User.Smart with a JSON null "name" property.
+     * @return User.Smart whose JSON has "name":null.
+     */
+    private static User.Smart userWithNullName() {
+        return new User.Smart(
+            new RtUser(
+                Mockito.mock(GitHub.class),
+                new FakeRequest().withBody(
+                    Json.createObjectBuilder()
+                        .addNull("name")
+                        .build()
+                        .toString()
+                ),
+                "octoc"
+            )
+        );
+    }
+
     /**
      * Return User.Smart with given property.
      * @param property The property as specified at https://developer.github.com/v3/users/#get-a-single-user