From 8da05e71f380edf170810d8193dcc426dd84faf4 Mon Sep 17 00:00:00 2001
From: Stephan Schroevers <stephan.schroevers@teampicnic.com>
Date: Sat, 26 Aug 2023 14:36:03 +0300
Subject: [PATCH] Introduce `CollectionContains` Refaster rule

---
 .../errorprone/refasterrules/CollectionRules.java   | 13 +++++++++++++
 .../refasterrules/CollectionRulesTestInput.java     |  4 ++++
 .../refasterrules/CollectionRulesTestOutput.java    |  4 ++++
 3 files changed, 21 insertions(+)

diff --git a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/CollectionRules.java b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/CollectionRules.java
index ba6146025ad..7a9802cb1fc 100644
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/CollectionRules.java
+++ b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/CollectionRules.java
@@ -74,6 +74,19 @@ int after(Collection<T> collection) {
     }
   }
 
+  /** Prefer {@link Collection#contains(Object)} over more contrived alternatives. */
+  static final class CollectionContains<T, S> {
+    @BeforeTemplate
+    boolean before(Collection<T> collection, S value) {
+      return collection.stream().anyMatch(value::equals);
+    }
+
+    @AfterTemplate
+    boolean after(Collection<T> collection, S value) {
+      return collection.contains(value);
+    }
+  }
+
   /**
    * Don't call {@link Iterables#addAll(Collection, Iterable)} when the elements to be added are
    * already part of a {@link Collection}.
diff --git a/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/CollectionRulesTestInput.java b/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/CollectionRulesTestInput.java
index 369a84cba00..735587515c9 100644
--- a/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/CollectionRulesTestInput.java
+++ b/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/CollectionRulesTestInput.java
@@ -36,6 +36,10 @@ ImmutableSet<Integer> testCollectionSize() {
     return ImmutableSet.of(Iterables.size(ImmutableSet.of(1)), ImmutableSet.of(2).asList().size());
   }
 
+  boolean testCollectionContains() {
+    return ImmutableSet.of("foo").stream().anyMatch("bar"::equals);
+  }
+
   boolean testCollectionAddAllToCollectionExpression() {
     return Iterables.addAll(new ArrayList<>(), ImmutableSet.of("foo"));
   }
diff --git a/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/CollectionRulesTestOutput.java b/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/CollectionRulesTestOutput.java
index 1f5380ec380..cf2040e33b0 100644
--- a/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/CollectionRulesTestOutput.java
+++ b/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/CollectionRulesTestOutput.java
@@ -36,6 +36,10 @@ ImmutableSet<Integer> testCollectionSize() {
     return ImmutableSet.of(ImmutableSet.of(1).size(), ImmutableSet.of(2).size());
   }
 
+  boolean testCollectionContains() {
+    return ImmutableSet.of("foo").contains("bar");
+  }
+
   boolean testCollectionAddAllToCollectionExpression() {
     return new ArrayList<>().addAll(ImmutableSet.of("foo"));
   }