From a07c36460862bdd823dc4c47fa959c20a72aec43 Mon Sep 17 00:00:00 2001
From: Sebastian Bergmann <sb@sebastian-bergmann.de>
Date: Mon, 30 Mar 2020 09:11:53 +0200
Subject: [PATCH] Closes #4133

---
 ChangeLog-8.5.md           |  1 +
 src/Framework/TestCase.php | 11 +++++++++++
 2 files changed, 12 insertions(+)

diff --git a/ChangeLog-8.5.md b/ChangeLog-8.5.md
index dd4e4c1bace..7a0673e015e 100644
--- a/ChangeLog-8.5.md
+++ b/ChangeLog-8.5.md
@@ -7,6 +7,7 @@ All notable changes of the PHPUnit 8.5 release series are documented in this fil
 ### Fixed
 
 * [#4017](https://github.com/sebastianbergmann/phpunit/issues/4017): Do not suggest refactoring to something that is also deprecated
+* [#4133](https://github.com/sebastianbergmann/phpunit/issues/4133): `expectExceptionMessageRegExp()` has been removed in PHPUnit 9 without a deprecation warning being given in PHPUnit 8
 * [#4139](https://github.com/sebastianbergmann/phpunit/issues/4139): Cannot double interfaces that declare a constructor with PHP 8
 * [#4144](https://github.com/sebastianbergmann/phpunit/issues/4144): Empty objects are converted to empty arrays in JSON comparison failure diff
 
diff --git a/src/Framework/TestCase.php b/src/Framework/TestCase.php
index e46a6d4638c..de79be048fe 100644
--- a/src/Framework/TestCase.php
+++ b/src/Framework/TestCase.php
@@ -269,6 +269,11 @@ abstract class TestCase extends Assert implements SelfDescribing, Test
      */
     private $doubledTypes = [];
 
+    /**
+     * @var bool
+     */
+    private $deprecatedExpectExceptionMessageRegExpUsed = false;
+
     /**
      * Returns a matcher that matches when the method is executed
      * zero or more times.
@@ -506,6 +511,8 @@ public function expectExceptionMessageMatches(string $regularExpression): void
      */
     public function expectExceptionMessageRegExp(string $regularExpression): void
     {
+        $this->deprecatedExpectExceptionMessageRegExpUsed = true;
+
         $this->expectExceptionMessageMatches($regularExpression);
     }
 
@@ -1447,6 +1454,10 @@ protected function runTest()
                 );
             }
 
+            if ($this->deprecatedExpectExceptionMessageRegExpUsed) {
+                $this->addWarning('expectExceptionMessageRegExp() is deprecated in PHPUnit 8 and will be removed in PHPUnit 9.');
+            }
+
             return;
         }