Model numberWithUnsignedInteger, skipping it was creating a false positive NPE

Reviewed By: akotulski

Differential Revision: D3561440

fbshipit-source-id: e03dfe4

infer/models/objc/src/NSNumber.m

@@ -55,4 +55,14 @@
   return self;
 }
 
+- (id)initWithUnsignedInteger:(NSUInteger)v {
+  self->value = v;
+  return self;
+}
+
++ (NSNumber*)numberWithUnsignedInteger:(NSUInteger)value {
+  NSNumber* number = [self alloc];
+  return [number initWithUnsignedInteger:value];
+}
+
 @end

infer/tests/codetoanalyze/objc/errors/npe/BoxedNumberExample.m

@@ -0,0 +1,36 @@
+/*
+ * Copyright (c) 2016 - present Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+#include <Foundation/Foundation.h>
+
+typedef NS_ENUM(NSUInteger, SpacingEnum) {
+  SpacingFill,
+  SpacingCenter,
+  SpacingLeading,
+  SpacingTrailing,
+};
+
+@interface A : NSObject
+
+@end
+
+@implementation A {
+  NSMutableDictionary* _spacingMap;
+}
+
+- (void)setMinimumHorizontalPadding:(SpacingEnum)horizontalSpacing
+                                and:(SpacingEnum)spacingValue {
+  NSNumber* key = @(horizontalSpacing);
+  NSNumber* value = @(spacingValue);
+  if ((_spacingMap[key] != value)) {
+    _spacingMap[key] = value;
+  }
+}
+
+@end

infer/tests/endtoend/objc/BoxedNumberNoNPETest.java

@@ -0,0 +1,66 @@
+/*
+ * Copyright (c) 2015 - present Facebook, Inc.
+ * All rights reserved.
+ *
+ * This source code is licensed under the BSD style license found in the
+ * LICENSE file in the root directory of this source tree. An additional grant
+ * of patent rights can be found in the PATENTS file in the same directory.
+ */
+
+package endtoend.objc;
+
+import static org.hamcrest.MatcherAssert.assertThat;
+import static utils.matchers.ResultContainsExactly.containsExactly;
+
+import com.google.common.collect.ImmutableList;
+
+import org.junit.BeforeClass;
+import org.junit.ClassRule;
+import org.junit.Test;
+
+import java.io.IOException;
+
+import utils.DebuggableTemporaryFolder;
+import utils.InferException;
+import utils.InferResults;
+import utils.InferRunner;
+
+public class BoxedNumberNoNPETest {
+
+  public static final String FILE =
+      "infer/tests/codetoanalyze/objc/errors/npe/BoxedNumberExample.m";
+
+  private static ImmutableList<String> inferCmd;
+
+  public static final String NULL_DEREFERENCE = "NULL_DEREFERENCE";
+
+  @ClassRule
+  public static DebuggableTemporaryFolder folder =
+      new DebuggableTemporaryFolder();
+
+  @BeforeClass
+  public static void runInfer() throws InterruptedException, IOException {
+    inferCmd = InferRunner.createiOSInferCommandWithMLBuckets(
+      folder,
+      FILE,
+      "cf",
+      true);
+  }
+
+  @Test
+  public void whenInferRunsOnBoxedExampleNoNPEIsFound()
+      throws InterruptedException, IOException, InferException {
+    InferResults inferResults = InferRunner.runInferC(inferCmd);
+    String[] procedures = {
+    };
+    assertThat(
+        "Results should contain no " + NULL_DEREFERENCE,
+        inferResults,
+        containsExactly(
+            NULL_DEREFERENCE,
+            FILE,
+            procedures
+        )
+    );
+  }
+}