Adding EmptyLibraryModels abstract class for LibraryModels interface

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

@@ -0,0 +1,92 @@
+/*
+ * Copyright (c) 2017 Uber Technologies, Inc.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+
+package com.uber.nullaway;
+
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.ImmutableSetMultimap;
+
+/**
+ * Provides a default implementation(returning appropriate empty sets) of every method defined by
+ * the LibraryModels interface.
+ *
+ * <p>Useful Library Model classes can subclass this class and implement only the methods for the
+ * hooks they actually need to take action on, rather than having to implement the entire
+ * LibraryModels interface. Additionally, we can add extensibility points without breaking existing
+ * library models, as long as we define the corresponding default behavior here.
+ */
+public abstract class EmptyLibraryModels implements LibraryModels {
+  @Override
+  public ImmutableSetMultimap<MethodRef, Integer> failIfNullParameters() {
+    return ImmutableSetMultimap.of();
+  }
+
+  @Override
+  public ImmutableSetMultimap<MethodRef, Integer> explicitlyNullableParameters() {
+    return ImmutableSetMultimap.of();
+  }
+
+  @Override
+  public ImmutableSetMultimap<MethodRef, Integer> nonNullParameters() {
+    return ImmutableSetMultimap.of();
+  }
+
+  @Override
+  public ImmutableSetMultimap<MethodRef, Integer> nullImpliesTrueParameters() {
+    return ImmutableSetMultimap.of();
+  }
+
+  @Override
+  public ImmutableSetMultimap<MethodRef, Integer> nullImpliesFalseParameters() {
+    return ImmutableSetMultimap.of();
+  }
+
+  @Override
+  public ImmutableSetMultimap<MethodRef, Integer> nullImpliesNullParameters() {
+    return ImmutableSetMultimap.of();
+  }
+
+  @Override
+  public ImmutableSet<MethodRef> nullableReturns() {
+    return ImmutableSet.of();
+  }
+
+  @Override
+  public ImmutableSet<MethodRef> nonNullReturns() {
+    return ImmutableSet.of();
+  }
+
+  @Override
+  public ImmutableSetMultimap<String, Integer> typeVariablesWithNullableUpperBounds() {
+    return ImmutableSetMultimap.of();
+  }
+
+  @Override
+  public ImmutableSetMultimap<MethodRef, Integer> castToNonNullMethods() {
+    return ImmutableSetMultimap.of();
+  }
+
+  @Override
+  public ImmutableSet<FieldRef> nullableFields() {
+    return ImmutableSet.of();
+  }
+}

nullaway/src/main/java/com/uber/nullaway/handlers/LibraryModelsHandler.java

@@ -42,6 +42,7 @@
 import com.sun.tools.javac.util.Names;
 import com.uber.nullaway.CodeAnnotationInfo;
 import com.uber.nullaway.Config;
+import com.uber.nullaway.EmptyLibraryModels;
 import com.uber.nullaway.LibraryModels;
 import com.uber.nullaway.LibraryModels.MethodRef;
 import com.uber.nullaway.NullAway;
@@ -376,7 +377,7 @@ private static LibraryModels loadLibraryModels(Config config) {
     return new CombinedLibraryModels(libModelsBuilder.build(), config);
   }
 
-  private static class DefaultLibraryModels implements LibraryModels {
+  private static class DefaultLibraryModels extends EmptyLibraryModels {
 
     private static final ImmutableSetMultimap<MethodRef, Integer> FAIL_IF_NULL_PARAMETERS =
         new ImmutableSetMultimap.Builder<MethodRef, Integer>()
@@ -898,7 +899,7 @@ public ImmutableSet<FieldRef> nullableFields() {
     }
   }
 
-  private static class CombinedLibraryModels implements LibraryModels {
+  private static class CombinedLibraryModels extends EmptyLibraryModels {
 
     private final Config config;
 

sample-library-model/src/main/java/com/uber/modelexample/ExampleLibraryModels.java

@@ -18,67 +18,16 @@
 import static com.uber.nullaway.LibraryModels.MethodRef.methodRef;
 
 import com.google.auto.service.AutoService;
-import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.ImmutableSetMultimap;
+import com.uber.nullaway.EmptyLibraryModels;
 import com.uber.nullaway.LibraryModels;
 
 @AutoService(LibraryModels.class)
-public class ExampleLibraryModels implements LibraryModels {
-
-  @Override
-  public ImmutableSetMultimap<MethodRef, Integer> failIfNullParameters() {
-    return ImmutableSetMultimap.of();
-  }
-
-  @Override
-  public ImmutableSetMultimap<MethodRef, Integer> explicitlyNullableParameters() {
-    return ImmutableSetMultimap.of();
-  }
-
-  @Override
-  public ImmutableSetMultimap<MethodRef, Integer> nonNullParameters() {
-    return ImmutableSetMultimap.of();
-  }
-
+public class ExampleLibraryModels extends EmptyLibraryModels {
   @Override
   public ImmutableSetMultimap<MethodRef, Integer> nullImpliesTrueParameters() {
     return ImmutableSetMultimap.<MethodRef, Integer>builder()
         .put(methodRef("org.utilities.StringUtils", "isEmptyOrNull(java.lang.CharSequence)"), 0)
         .build();
   }
-
-  @Override
-  public ImmutableSetMultimap<MethodRef, Integer> nullImpliesFalseParameters() {
-    return ImmutableSetMultimap.of();
-  }
-
-  @Override
-  public ImmutableSetMultimap<MethodRef, Integer> nullImpliesNullParameters() {
-    return ImmutableSetMultimap.of();
-  }
-
-  @Override
-  public ImmutableSet<MethodRef> nullableReturns() {
-    return ImmutableSet.of();
-  }
-
-  @Override
-  public ImmutableSet<MethodRef> nonNullReturns() {
-    return ImmutableSet.of();
-  }
-
-  @Override
-  public ImmutableSetMultimap<String, Integer> typeVariablesWithNullableUpperBounds() {
-    return ImmutableSetMultimap.of();
-  }
-
-  @Override
-  public ImmutableSetMultimap<MethodRef, Integer> castToNonNullMethods() {
-    return ImmutableSetMultimap.of();
-  }
-
-  @Override
-  public ImmutableSet<FieldRef> nullableFields() {
-    return ImmutableSet.of();
-  }
 }

test-library-models/src/main/java/com/uber/nullaway/testlibrarymodels/TestLibraryModels.java

@@ -22,22 +22,13 @@
 import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.ImmutableSetMultimap;
+import com.uber.nullaway.EmptyLibraryModels;
 import com.uber.nullaway.LibraryModels;
 import com.uber.nullaway.handlers.stream.StreamModelBuilder;
 import com.uber.nullaway.handlers.stream.StreamTypeRecord;
 
 @AutoService(LibraryModels.class)
-public class TestLibraryModels implements LibraryModels {
-
-  @Override
-  public ImmutableSetMultimap<MethodRef, Integer> failIfNullParameters() {
-    return ImmutableSetMultimap.of();
-  }
-
-  @Override
-  public ImmutableSetMultimap<MethodRef, Integer> explicitlyNullableParameters() {
-    return ImmutableSetMultimap.of();
-  }
+public class TestLibraryModels extends EmptyLibraryModels {
 
   @Override
   public ImmutableSetMultimap<MethodRef, Integer> nonNullParameters() {
@@ -50,23 +41,13 @@ public ImmutableSetMultimap<MethodRef, Integer> nonNullParameters() {
         .build();
   }
 
-  @Override
-  public ImmutableSetMultimap<MethodRef, Integer> nullImpliesTrueParameters() {
-    return ImmutableSetMultimap.of();
-  }
-
   @Override
   public ImmutableSetMultimap<MethodRef, Integer> nullImpliesFalseParameters() {
     return ImmutableSetMultimap.of(
         methodRef("com.uber.lib.unannotated.UnannotatedWithModels", "isNonNull(java.lang.Object)"),
         0);
   }
 
-  @Override
-  public ImmutableSetMultimap<MethodRef, Integer> nullImpliesNullParameters() {
-    return ImmutableSetMultimap.of();
-  }
-
   @Override
   public ImmutableSet<MethodRef> nullableReturns() {
     return ImmutableSet.of(
@@ -75,16 +56,6 @@ public ImmutableSet<MethodRef> nullableReturns() {
         methodRef("com.uber.lib.unannotated.UnannotatedWithModels", "returnsNullUnannotated2()"));
   }
 
-  @Override
-  public ImmutableSet<MethodRef> nonNullReturns() {
-    return ImmutableSet.of();
-  }
-
-  @Override
-  public ImmutableSetMultimap<String, Integer> typeVariablesWithNullableUpperBounds() {
-    return ImmutableSetMultimap.of();
-  }
-
   @Override
   public ImmutableSetMultimap<MethodRef, Integer> castToNonNullMethods() {
     return ImmutableSetMultimap.<MethodRef, Integer>builder()