From cfd1f79a682a5ce9cc317a6f89bf29177855c90c Mon Sep 17 00:00:00 2001
From: Kurt Alfred Kluever <kak@google.com>
Date: Thu, 9 Jan 2025 11:22:27 -0800
Subject: [PATCH] Add a test for `static` `Function` lambdas that are not
 `UPPER_CASED`.

PiperOrigin-RevId: 713736769
---
 .../bugpatterns/UnnecessaryLambdaTest.java    | 37 +++++++++++++++++++
 1 file changed, 37 insertions(+)

diff --git a/core/src/test/java/com/google/errorprone/bugpatterns/UnnecessaryLambdaTest.java b/core/src/test/java/com/google/errorprone/bugpatterns/UnnecessaryLambdaTest.java
index c17bc87f65b..9a44ad57802 100644
--- a/core/src/test/java/com/google/errorprone/bugpatterns/UnnecessaryLambdaTest.java
+++ b/core/src/test/java/com/google/errorprone/bugpatterns/UnnecessaryLambdaTest.java
@@ -260,6 +260,43 @@ void g() {
         .doTest();
   }
 
+  @Test
+  public void variable_static_butNotUpperCased() {
+    testHelper
+        .addInputLines(
+            "Test.java",
+            """
+            import java.util.function.Function;
+
+            class Test {
+              private static final Function<String, String> notUpperCased = x -> "hello " + x;
+
+              void g() {
+                Function<String, String> l = Test.notUpperCased;
+                System.err.println(notUpperCased.apply("world"));
+              }
+            }
+            """)
+        // TODO: b/388821905 - we should retain the camelCasing of the variable name
+        .addOutputLines(
+            "Test.java",
+            """
+            import java.util.function.Function;
+
+            class Test {
+              private static String notuppercased(String x) {
+                return "hello " + x;
+              }
+
+              void g() {
+                Function<String, String> l = Test::notuppercased;
+                System.err.println(notuppercased("world"));
+              }
+            }
+            """)
+        .doTest();
+  }
+
   @Test
   public void method_shapes() {
     testHelper