From 909b9c7250a450e2567cb754c11a28bc04eda2d1 Mon Sep 17 00:00:00 2001
From: Anatolii Bivol <toleabivol@gmail.com>
Date: Sun, 4 Sep 2022 09:03:04 +0200
Subject: [PATCH 1/3] preserve substitutions from To in Personalization

If there are substitutions in the To object preserve them by transfering them to the Personalization object
---
 lib/mail/Personalization.php | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/lib/mail/Personalization.php b/lib/mail/Personalization.php
index 020e8245..289ed0a4 100644
--- a/lib/mail/Personalization.php
+++ b/lib/mail/Personalization.php
@@ -43,11 +43,19 @@ class Personalization implements \JsonSerializable
 
     /**
      * Add a To object to a Personalization object
+     * If there are substitutions in the To object preserve them 
+     * by transfering them to the Personalization object
      *
      * @param To $email To object
      */
     public function addTo($email)
     {
+        if ($subs = $email->getSubstitutions()) {
+            foreach ($subs as $key => $value) {
+                $this->addSubstitution($key, $value);
+            }
+        }
+        
         $this->tos[] = $email;
     }
 

From dd95642b201c01550cb2068c2fdb9d800cc9719d Mon Sep 17 00:00:00 2001
From: Anatolii Bivol <toleabivol@gmail.com>
Date: Sun, 4 Sep 2022 09:50:38 +0200
Subject: [PATCH 2/3] Personalization addSubstitution takes precedence; Unit
 test personalization addTo

---
 lib/mail/Personalization.php      | 11 +++++++----
 test/unit/PersonalizationTest.php | 27 +++++++++++++++++++++++++++
 2 files changed, 34 insertions(+), 4 deletions(-)

diff --git a/lib/mail/Personalization.php b/lib/mail/Personalization.php
index 289ed0a4..80966417 100644
--- a/lib/mail/Personalization.php
+++ b/lib/mail/Personalization.php
@@ -43,19 +43,22 @@ class Personalization implements \JsonSerializable
 
     /**
      * Add a To object to a Personalization object
-     * If there are substitutions in the To object preserve them 
-     * by transfering them to the Personalization object
+     * If there are substitutions in the To object preserve them
+     * by transferring them to the Personalization object
      *
      * @param To $email To object
      */
     public function addTo($email)
     {
         if ($subs = $email->getSubstitutions()) {
+            $existing_subs = $this->getSubstitutions();
             foreach ($subs as $key => $value) {
-                $this->addSubstitution($key, $value);
+                if (!array_key_exists($key, $existing_subs)) {
+                    $this->addSubstitution($key, $value);
+                }
             }
         }
-        
+
         $this->tos[] = $email;
     }
 
diff --git a/test/unit/PersonalizationTest.php b/test/unit/PersonalizationTest.php
index 9bd35ba4..f4417e95 100644
--- a/test/unit/PersonalizationTest.php
+++ b/test/unit/PersonalizationTest.php
@@ -16,6 +16,7 @@
 use SendGrid\Mail\Subject;
 use SendGrid\Mail\To;
 use SendGrid\Mail\TypeException;
+use SendGrid\Mail\Substitution;
 
 /**
  * This class tests Personalization.
@@ -32,6 +33,32 @@ public function testAddTo()
         $this->assertSame('dx@sendgrid.com', $personalization->getTos()[0]->getEmail());
     }
 
+    public function testAddToWithSubstitution()
+    {
+        $personalization = new Personalization();
+        $personalization->addTo(new To('dx@sendgrid.com', 'Test with sub',
+            [
+                '-name-' => 'Example User'
+            ]
+        ));
+
+        $this->assertArrayHasKey('-name-', $personalization->getSubstitutions());
+    }
+
+    public function testAddSubstitutionHasPrecedence()
+    {
+        $personalization = new Personalization();
+        $personalization->addSubstitution(new Substitution('-name-', 'Example User 2'));
+        $personalization->addTo(new To('dx@sendgrid.com', 'Test with sub',
+            [
+                '-name-' => 'Example User'
+            ]
+        ));
+
+        $this->assertArrayHasKey('-name-', $personalization->getSubstitutions());
+        $this->assertSame('Example User 2', $personalization->getSubstitutions()['-name-']);
+    }
+
     public function testAddFrom()
     {
         $personalization = new Personalization();

From 8a8633f98df2d762ea80c06e72d87b96bb0bc223 Mon Sep 17 00:00:00 2001
From: Anatolii Bivol <toleabivol@gmail.com>
Date: Sun, 4 Sep 2022 09:52:56 +0200
Subject: [PATCH 3/3] Personalization addTo inline doc

---
 lib/mail/Personalization.php | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/lib/mail/Personalization.php b/lib/mail/Personalization.php
index 80966417..7fb57e9d 100644
--- a/lib/mail/Personalization.php
+++ b/lib/mail/Personalization.php
@@ -44,7 +44,9 @@ class Personalization implements \JsonSerializable
     /**
      * Add a To object to a Personalization object
      * If there are substitutions in the To object preserve them
-     * by transferring them to the Personalization object
+     * by transferring them to the Personalization object.
+     * If a substitution with the same key already exists
+     * that takes precedence, and we don't overwrite
      *
      * @param To $email To object
      */