Ignore fields that are annotated with the @MockBean and @SpyBean …

…annotations of Spring test (#757)

This is a small followup to #477. When you are testing Spring (Boot)
applications then you are replacing controllers that are normally
injected via `@Autowired` with stubs, mocks or spies from Mockito. This
is done with two similar annotations:

- `@MockBean`
- `@SpyBean`

So it would be helpful if these are ignored as well.

nullaway/src/main/java/com/uber/nullaway/ErrorProneCLIFlagsConfig.java

@@ -152,7 +152,9 @@ final class ErrorProneCLIFlagsConfig extends AbstractConfig {
           "javax.inject.Inject", // no explicit initialization when there is dependency injection
           "com.google.errorprone.annotations.concurrent.LazyInit",
           "org.checkerframework.checker.nullness.qual.MonotonicNonNull",
-          "org.springframework.beans.factory.annotation.Autowired");
+          "org.springframework.beans.factory.annotation.Autowired",
+          "org.springframework.boot.test.mock.mockito.MockBean",
+          "org.springframework.boot.test.mock.mockito.SpyBean");
 
   private static final String DEFAULT_URL = "http://t.uber.com/nullaway";
 

nullaway/src/test/java/com/uber/nullaway/NullAwayFrameworkTests.java

@@ -262,6 +262,43 @@ public void springAutowiredFieldTest() {
         .doTest();
   }
 
+  @Test
+  public void springTestAutowiredFieldTest() {
+    defaultCompilationHelper
+        .addSourceFile("springboot-annotations/MockBean.java")
+        .addSourceFile("springboot-annotations/SpyBean.java")
+        .addSourceLines(
+            "Foo.java",
+            "package com.uber;",
+            "import javax.annotation.Nullable;",
+            "import org.springframework.stereotype.Component;",
+            "@Component",
+            "public class Foo {",
+            "  @Nullable String bar;",
+            "  public void setBar(String s) {",
+            "    bar = s;",
+            "  }",
+            "}")
+        .addSourceLines(
+            "TestCase.java",
+            "package com.uber;",
+            "import org.junit.jupiter.api.Test;",
+            "import org.springframework.boot.test.mock.mockito.SpyBean;",
+            "import org.springframework.boot.test.mock.mockito.MockBean;",
+            "public class TestCase {",
+            "  @SpyBean",
+            "  private Foo spy;", // Initialized by spring test (via Mockito).
+            "  @MockBean",
+            "  private Foo mock;", // Initialized by spring test (via Mockito).
+            "  @Test",
+            "  void springTest() {",
+            "    spy.setBar(\"hello\");",
+            "    mock.setBar(\"hello\");",
+            "  }",
+            "}")
+        .doTest();
+  }
+
   @Test
   public void springAutowiredConstructorTest() {
     defaultCompilationHelper

nullaway/src/test/resources/com/uber/nullaway/testdata/springboot-annotations/MockBean.java

@@ -0,0 +1,13 @@
+package org.springframework.boot.test.mock.mockito;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Target({ElementType.TYPE, ElementType.FIELD})
+@Retention(RetentionPolicy.RUNTIME)
+@Documented
+public @interface MockBean {
+}

nullaway/src/test/resources/com/uber/nullaway/testdata/springboot-annotations/SpyBean.java

@@ -0,0 +1,13 @@
+package org.springframework.boot.test.mock.mockito;
+
+import java.lang.annotation.Documented;
+import java.lang.annotation.ElementType;
+import java.lang.annotation.Retention;
+import java.lang.annotation.RetentionPolicy;
+import java.lang.annotation.Target;
+
+@Target({ElementType.TYPE, ElementType.FIELD})
+@Retention(RetentionPolicy.RUNTIME)
+@Documented
+public @interface SpyBean {
+}