Turn on additional IntelliJ inspections and fix violations. #1323

Signed-off-by: Alexander Goldberg <alexander.goldberg@bnymellon.com>

eclipse-collections-code-generator/src/main/java/org/eclipse/collections/codegenerator/ErrorListener.java

@@ -10,6 +10,7 @@
 
 package org.eclipse.collections.codegenerator;
 
+@FunctionalInterface
 public interface ErrorListener
 {
     void error(String string);

eclipse-collections-testutils/src/main/java/org/eclipse/collections/impl/test/Verify.java

@@ -281,19 +281,19 @@ public static void assertEmpty(String mutableMapIterableName, MutableMapIterable
             {
                 Assert.fail(mutableMapIterableName + " should be empty; actual size:<" + Iterate.sizeOf(actualMutableMapIterable) + '>');
             }
-            if (actualMutableMapIterable.size() != 0)
+            if (!actualMutableMapIterable.isEmpty())
             {
                 Assert.fail(mutableMapIterableName + " should be empty; actual size:<" + actualMutableMapIterable.size() + '>');
             }
-            if (actualMutableMapIterable.keySet().size() != 0)
+            if (!actualMutableMapIterable.keySet().isEmpty())
             {
                 Assert.fail(mutableMapIterableName + " should be empty; actual size:<" + actualMutableMapIterable.keySet().size() + '>');
             }
-            if (actualMutableMapIterable.values().size() != 0)
+            if (!actualMutableMapIterable.values().isEmpty())
             {
                 Assert.fail(mutableMapIterableName + " should be empty; actual size:<" + actualMutableMapIterable.values().size() + '>');
             }
-            if (actualMutableMapIterable.entrySet().size() != 0)
+            if (!actualMutableMapIterable.entrySet().isEmpty())
             {
                 Assert.fail(mutableMapIterableName + " should be empty; actual size:<" + actualMutableMapIterable.entrySet().size() + '>');
             }
@@ -322,6 +322,7 @@ public static void assertEmpty(PrimitiveIterable primitiveIterable)
     /**
      * Assert that the given {@link PrimitiveIterable} is empty.
      */
+    @SuppressWarnings("SizeReplaceableByIsEmpty")
     public static void assertEmpty(String iterableName, PrimitiveIterable primitiveIterable)
     {
         try
@@ -489,6 +490,7 @@ public static void assertEmpty(Multimap<?, ?> actualMultimap)
     /**
      * Assert that the given {@link Multimap} is empty.
      */
+    @SuppressWarnings("SizeReplaceableByIsEmpty")
     public static void assertEmpty(String multimapName, Multimap<?, ?> actualMultimap)
     {
         try
@@ -511,23 +513,23 @@ public static void assertEmpty(String multimapName, Multimap<?, ?> actualMultima
             {
                 Assert.fail(multimapName + " should be empty; actual size:<" + actualMultimap.size() + '>');
             }
-            if (actualMultimap.keyBag().size() != 0)
+            if (!actualMultimap.keyBag().isEmpty())
             {
                 Assert.fail(multimapName + " should be empty; actual size:<" + actualMultimap.keyBag().size() + '>');
             }
-            if (actualMultimap.keysView().size() != 0)
+            if (!actualMultimap.keysView().isEmpty())
             {
                 Assert.fail(multimapName + " should be empty; actual size:<" + actualMultimap.keysView().size() + '>');
             }
-            if (actualMultimap.valuesView().size() != 0)
+            if (!actualMultimap.valuesView().isEmpty())
             {
                 Assert.fail(multimapName + " should be empty; actual size:<" + actualMultimap.valuesView().size() + '>');
             }
-            if (actualMultimap.keyValuePairsView().size() != 0)
+            if (!actualMultimap.keyValuePairsView().isEmpty())
             {
                 Assert.fail(multimapName + " should be empty; actual size:<" + actualMultimap.keyValuePairsView().size() + '>');
             }
-            if (actualMultimap.keyMultiValuePairsView().size() != 0)
+            if (!actualMultimap.keyMultiValuePairsView().isEmpty())
             {
                 Assert.fail(multimapName + " should be empty; actual size:<" + actualMultimap.keyMultiValuePairsView().size() + '>');
             }
@@ -541,6 +543,7 @@ public static void assertEmpty(String multimapName, Multimap<?, ?> actualMultima
     /**
      * Assert that the given {@link Map} is empty.
      */
+    @SuppressWarnings("SizeReplaceableByIsEmpty")
     public static void assertEmpty(String mapName, Map<?, ?> actualMap)
     {
         try
@@ -555,15 +558,15 @@ public static void assertEmpty(String mapName, Map<?, ?> actualMap)
             {
                 Assert.fail(mapName + " should be empty; actual size:<" + actualMap.size() + '>');
             }
-            if (actualMap.keySet().size() != 0)
+            if (!actualMap.keySet().isEmpty())
             {
                 Assert.fail(mapName + " should be empty; actual size:<" + actualMap.keySet().size() + '>');
             }
-            if (actualMap.values().size() != 0)
+            if (!actualMap.values().isEmpty())
             {
                 Assert.fail(mapName + " should be empty; actual size:<" + actualMap.values().size() + '>');
             }
-            if (actualMap.entrySet().size() != 0)
+            if (!actualMap.entrySet().isEmpty())
             {
                 Assert.fail(mapName + " should be empty; actual size:<" + actualMap.entrySet().size() + '>');
             }

eclipse-collections/src/main/java/org/eclipse/collections/impl/block/factory/StringPredicates.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021 Goldman Sachs.
+ * Copyright (c) 2022 Goldman Sachs and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * and Eclipse Distribution License v. 1.0 which accompany this distribution.
@@ -202,7 +202,7 @@ private static class Empty extends Predicates<String>
         @Override
         public boolean accept(String anObject)
         {
-            return anObject != null && anObject.length() == 0;
+            return anObject != null && anObject.isEmpty();
         }
 
         @Override
@@ -219,7 +219,7 @@ private static class NotEmpty extends Predicates<String>
         @Override
         public boolean accept(String anObject)
         {
-            return anObject != null && anObject.length() > 0;
+            return anObject != null && !anObject.isEmpty();
         }
 
         @Override

eclipse-collections/src/main/java/org/eclipse/collections/impl/block/function/checked/ThrowingFunction.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021 Goldman Sachs.
+ * Copyright (c) 2022 Goldman Sachs and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * and Eclipse Distribution License v. 1.0 which accompany this distribution.
@@ -15,6 +15,7 @@
 /**
  * A functional interface that can be represented by a Lambda that can throw a CheckedException.
  */
+@FunctionalInterface
 public interface ThrowingFunction<T, V> extends Serializable
 {
     @SuppressWarnings("ProhibitedExceptionDeclared")

eclipse-collections/src/main/java/org/eclipse/collections/impl/block/function/checked/ThrowingFunction0.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021 Goldman Sachs.
+ * Copyright (c) 2022 Goldman Sachs.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * and Eclipse Distribution License v. 1.0 which accompany this distribution.
@@ -15,6 +15,7 @@
 /**
  * A functional interface that can be represented by a Lambda that can throw a CheckedException.
  */
+@FunctionalInterface
 public interface ThrowingFunction0<R> extends Serializable
 {
     @SuppressWarnings("ProhibitedExceptionDeclared")

eclipse-collections/src/main/java/org/eclipse/collections/impl/block/function/checked/ThrowingFunction2.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021 Goldman Sachs.
+ * Copyright (c) 2022 Goldman Sachs.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * and Eclipse Distribution License v. 1.0 which accompany this distribution.
@@ -15,6 +15,7 @@
 /**
  * A functional interface that can be represented by a Lambda that can throw a CheckedException.
  */
+@FunctionalInterface
 public interface ThrowingFunction2<T1, T2, R> extends Serializable
 {
     @SuppressWarnings("ProhibitedExceptionDeclared")

eclipse-collections/src/main/java/org/eclipse/collections/impl/block/function/primitive/CharFunction.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021 Goldman Sachs.
+ * Copyright (c) 2022 Goldman Sachs and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * and Eclipse Distribution License v. 1.0 which accompany this distribution.
@@ -19,6 +19,7 @@
  *
  * @deprecated since 3.0. Use {@link CharToCharFunction} instead.
  */
+@FunctionalInterface
 @Deprecated
 public interface CharFunction
         extends Serializable

eclipse-collections/src/main/java/org/eclipse/collections/impl/block/function/primitive/CodePointFunction.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021 Goldman Sachs.
+ * Copyright (c) 2022 Goldman Sachs and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * and Eclipse Distribution License v. 1.0 which accompany this distribution.
@@ -15,6 +15,7 @@
 /**
  * A CharFunction can be used to convert one character to another.
  */
+@FunctionalInterface
 public interface CodePointFunction
         extends Serializable
 {

eclipse-collections/src/main/java/org/eclipse/collections/impl/block/predicate/CodePointPredicate.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021 Goldman Sachs.
+ * Copyright (c) 2022 Goldman Sachs and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * and Eclipse Distribution License v. 1.0 which accompany this distribution.
@@ -15,6 +15,7 @@
 /**
  * A Predicate that accepts an int value
  */
+@FunctionalInterface
 public interface CodePointPredicate
         extends Serializable
 {

eclipse-collections/src/main/java/org/eclipse/collections/impl/block/predicate/checked/ThrowingPredicate.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021 Goldman Sachs.
+ * Copyright (c) 2022 Goldman Sachs and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * and Eclipse Distribution License v. 1.0 which accompany this distribution.
@@ -15,6 +15,7 @@
 /**
  * A functional interface that can be represented by a Lambda that can throw a CheckedException.
  */
+@FunctionalInterface
 public interface ThrowingPredicate<T> extends Serializable
 {
     @SuppressWarnings("ProhibitedExceptionDeclared")

eclipse-collections/src/main/java/org/eclipse/collections/impl/block/predicate/checked/ThrowingPredicate2.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021 Goldman Sachs.
+ * Copyright (c) 2022 Goldman Sachs and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * and Eclipse Distribution License v. 1.0 which accompany this distribution.
@@ -15,6 +15,7 @@
 /**
  * A functional interface that can be represented by a Lambda that can throw a CheckedException.
  */
+@FunctionalInterface
 public interface ThrowingPredicate2<T, P> extends Serializable
 {
     @SuppressWarnings("ProhibitedExceptionDeclared")

eclipse-collections/src/main/java/org/eclipse/collections/impl/block/predicate/primitive/CharPredicate.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021 Goldman Sachs.
+ * Copyright (c) 2022 Goldman Sachs and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * and Eclipse Distribution License v. 1.0 which accompany this distribution.
@@ -17,6 +17,7 @@
  *
  * @deprecated since 3.0. Use {@link org.eclipse.collections.api.block.predicate.primitive.CharPredicate} instead.
  */
+@FunctionalInterface
 @Deprecated
 public interface CharPredicate
         extends Serializable

eclipse-collections/src/main/java/org/eclipse/collections/impl/block/procedure/checked/ThrowingProcedure.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021 Goldman Sachs.
+ * Copyright (c) 2022 Goldman Sachs and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * and Eclipse Distribution License v. 1.0 which accompany this distribution.
@@ -15,6 +15,7 @@
 /**
  * A functional interface that can be represented by a Lambda that can throw a CheckedException.
  */
+@FunctionalInterface
 public interface ThrowingProcedure<T> extends Serializable
 {
     @SuppressWarnings("ProhibitedExceptionDeclared")

eclipse-collections/src/main/java/org/eclipse/collections/impl/block/procedure/checked/ThrowingProcedure2.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021 Goldman Sachs.
+ * Copyright (c) 2022 Goldman Sachs and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * and Eclipse Distribution License v. 1.0 which accompany this distribution.
@@ -15,6 +15,7 @@
 /**
  * A functional interface that can be represented by a Lambda that can throw a CheckedException.
  */
+@FunctionalInterface
 public interface ThrowingProcedure2<T, P> extends Serializable
 {
     @SuppressWarnings("ProhibitedExceptionDeclared")

eclipse-collections/src/main/java/org/eclipse/collections/impl/block/procedure/primitive/CharProcedure.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021 Goldman Sachs.
+ * Copyright (c) 2022 Goldman Sachs and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * and Eclipse Distribution License v. 1.0 which accompany this distribution.
@@ -13,6 +13,7 @@
 /**
  * @deprecated since 3.0 use {@link org.eclipse.collections.api.block.procedure.primitive.CharProcedure}
  */
+@FunctionalInterface
 @Deprecated
 public interface CharProcedure
 {

eclipse-collections/src/main/java/org/eclipse/collections/impl/block/procedure/primitive/CodePointProcedure.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021 Goldman Sachs.
+ * Copyright (c) 2022 Goldman Sachs and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * and Eclipse Distribution License v. 1.0 which accompany this distribution.
@@ -10,6 +10,7 @@
 
 package org.eclipse.collections.impl.block.procedure.primitive;
 
+@FunctionalInterface
 public interface CodePointProcedure
 {
     void value(int codePoint);

eclipse-collections/src/main/java/org/eclipse/collections/impl/block/procedure/primitive/IntIntProcedure.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021 Goldman Sachs.
+ * Copyright (c) 2022 Goldman Sachs and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * and Eclipse Distribution License v. 1.0 which accompany this distribution.
@@ -18,6 +18,7 @@
  *
  * @deprecated since 3.0 use {@link org.eclipse.collections.api.block.procedure.primitive.IntIntProcedure}
  */
+@FunctionalInterface
 @Deprecated
 public interface IntIntProcedure extends Serializable
 {

eclipse-collections/src/main/java/org/eclipse/collections/impl/block/procedure/primitive/IntObjectProcedure.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021 Goldman Sachs.
+ * Copyright (c) 2022 Goldman Sachs and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * and Eclipse Distribution License v. 1.0 which accompany this distribution.
@@ -13,6 +13,7 @@
 /**
  * @deprecated since 3.0 use {@link org.eclipse.collections.api.block.procedure.primitive.IntObjectProcedure}
  */
+@FunctionalInterface
 @Deprecated
 public interface IntObjectProcedure<T>
 {

eclipse-collections/src/main/java/org/eclipse/collections/impl/block/procedure/primitive/IntProcedure.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021 Goldman Sachs.
+ * Copyright (c) 2022 Goldman Sachs and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * and Eclipse Distribution License v. 1.0 which accompany this distribution.
@@ -13,6 +13,7 @@
 /**
  * @deprecated since 3.0 use {@link org.eclipse.collections.api.block.procedure.primitive.IntProcedure}
  */
+@FunctionalInterface
 @Deprecated
 public interface IntProcedure
 {