From a373a277cd6d6d79f8e80f38aba7abbfde0e1f8b Mon Sep 17 00:00:00 2001
From: Stephan Schroevers <stephan.schroevers@teampicnic.com>
Date: Thu, 11 May 2023 07:38:06 +0200
Subject: [PATCH] Introduce `PatternRules` Refaster rule collection

While there, configure `StaticImport` to not require static importing of
`com.google.common.base.Predicates.contains`.

See google/guava#6483.
---
 .../errorprone/bugpatterns/StaticImport.java  |  1 +
 .../refasterrules/PatternRules.java           | 46 +++++++++++++++++++
 .../refasterrules/PatternRulesTestInput.java  | 22 +++++++++
 .../refasterrules/PatternRulesTestOutput.java | 22 +++++++++
 4 files changed, 91 insertions(+)
 create mode 100644 error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/PatternRules.java
 create mode 100644 error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/PatternRulesTestInput.java
 create mode 100644 error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/PatternRulesTestOutput.java

diff --git a/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/StaticImport.java b/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/StaticImport.java
index 6063562002f..c5b3e524277 100644
--- a/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/StaticImport.java
+++ b/error-prone-contrib/src/main/java/tech/picnic/errorprone/bugpatterns/StaticImport.java
@@ -155,6 +155,7 @@ public final class StaticImport extends BugChecker implements MemberSelectTreeMa
   @VisibleForTesting
   static final ImmutableSetMultimap<String, String> STATIC_IMPORT_EXEMPTED_MEMBERS =
       ImmutableSetMultimap.<String, String>builder()
+          .put("com.google.common.base.Predicates", "contains")
           .put("com.mongodb.client.model.Filters", "empty")
           .putAll(
               "java.util.Collections",
diff --git a/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/PatternRules.java b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/PatternRules.java
new file mode 100644
index 00000000000..39ad88262b4
--- /dev/null
+++ b/error-prone-contrib/src/main/java/tech/picnic/errorprone/refasterrules/PatternRules.java
@@ -0,0 +1,46 @@
+package tech.picnic.errorprone.refasterrules;
+
+import static com.google.common.base.Predicates.containsPattern;
+
+import com.google.common.base.Predicates;
+import com.google.errorprone.refaster.annotation.AfterTemplate;
+import com.google.errorprone.refaster.annotation.BeforeTemplate;
+import java.util.function.Predicate;
+import java.util.regex.Pattern;
+import tech.picnic.errorprone.refaster.annotation.OnlineDocumentation;
+
+/** Refaster rules related to code dealing with regular expressions. */
+@OnlineDocumentation
+final class PatternRules {
+  private PatternRules() {}
+
+  /** Prefer {@link Pattern#asPredicate()} over non-JDK alternatives. */
+  // XXX: This rule could also replace `s -> pattern.matcher(s).find()`, though the lambda
+  // expression may match functional interfaces other than `Predicate`. If we do add such a rule, we
+  // should also add a rule that replaces `s -> pattern.matcher(s).matches()` with
+  // `pattern.asMatchPredicate()`.
+  static final class PatternAsPredicate {
+    @BeforeTemplate
+    Predicate<CharSequence> before(Pattern pattern) {
+      return Predicates.contains(pattern);
+    }
+
+    @AfterTemplate
+    Predicate<String> after(Pattern pattern) {
+      return pattern.asPredicate();
+    }
+  }
+
+  /** Prefer {@link Pattern#asPredicate()} over non-JDK alternatives. */
+  static final class PatternCompileAsPredicate {
+    @BeforeTemplate
+    Predicate<CharSequence> before(String pattern) {
+      return containsPattern(pattern);
+    }
+
+    @AfterTemplate
+    Predicate<String> after(String pattern) {
+      return Pattern.compile(pattern).asPredicate();
+    }
+  }
+}
diff --git a/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/PatternRulesTestInput.java b/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/PatternRulesTestInput.java
new file mode 100644
index 00000000000..2b19d9ea887
--- /dev/null
+++ b/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/PatternRulesTestInput.java
@@ -0,0 +1,22 @@
+package tech.picnic.errorprone.refasterrules;
+
+import com.google.common.base.Predicates;
+import com.google.common.collect.ImmutableSet;
+import java.util.function.Predicate;
+import java.util.regex.Pattern;
+import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
+
+final class PatternRulesTest implements RefasterRuleCollectionTestCase {
+  @Override
+  public ImmutableSet<Object> elidedTypesAndStaticImports() {
+    return ImmutableSet.of(Predicates.class);
+  }
+
+  Predicate<?> testPatternAsPredicate() {
+    return Predicates.contains(Pattern.compile("foo"));
+  }
+
+  Predicate<?> testPatternCompileAsPredicate() {
+    return Predicates.containsPattern("foo");
+  }
+}
diff --git a/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/PatternRulesTestOutput.java b/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/PatternRulesTestOutput.java
new file mode 100644
index 00000000000..9e774fd4742
--- /dev/null
+++ b/error-prone-contrib/src/test/resources/tech/picnic/errorprone/refasterrules/PatternRulesTestOutput.java
@@ -0,0 +1,22 @@
+package tech.picnic.errorprone.refasterrules;
+
+import com.google.common.base.Predicates;
+import com.google.common.collect.ImmutableSet;
+import java.util.function.Predicate;
+import java.util.regex.Pattern;
+import tech.picnic.errorprone.refaster.test.RefasterRuleCollectionTestCase;
+
+final class PatternRulesTest implements RefasterRuleCollectionTestCase {
+  @Override
+  public ImmutableSet<Object> elidedTypesAndStaticImports() {
+    return ImmutableSet.of(Predicates.class);
+  }
+
+  Predicate<?> testPatternAsPredicate() {
+    return Pattern.compile("foo").asPredicate();
+  }
+
+  Predicate<?> testPatternCompileAsPredicate() {
+    return Pattern.compile("foo").asPredicate();
+  }
+}