minor #50297 Remove unnecessary usages of DateTime (nicolas-grekas)

This PR was merged into the 6.4 branch.

Discussion
----------

Remove unnecessary usages of DateTime

| Q             | A
| ------------- | ---
| Branch?       | 6.3
| Bug fix?      | no
| New feature?  | no
| Deprecations? | no
| Tickets       | Part of #47580
| License       | MIT
| Doc PR        | -

Together with #50290, this PR removes `DateTime` everywhere possible.

What remains is:
- test cases that test both DateTime and DateTimeImmutable - legit to keep
- date/time form-types and transformers in the Form component - we'd need a separate effort for them, related to #50295
- `PersistentTokenInterface::getLastUsed(): \DateTime` - separate effort also

Commits
-------

8b08294b63 Remove unnecessary usages of DateTime

Author: fabpot

BinaryFileResponse.php

@@ -125,7 +125,7 @@ public function setChunkSize(int $chunkSize): static
      */
     public function setAutoLastModified(): static
     {
-        $this->setLastModified(\DateTime::createFromFormat('U', $this->file->getMTime()));
+        $this->setLastModified(\DateTimeImmutable::createFromFormat('U', $this->file->getMTime()));
 
         return $this;
     }

CHANGELOG.md

@@ -1,6 +1,11 @@
 CHANGELOG
 =========
 
+6.4
+---
+
+ * Make `HeaderBag::getDate()`, `Response::getDate()`, `getExpires()` and `getLastModified()` return a `DateTimeImmutable`
+
 6.3
 ---
 

HeaderBag.php

@@ -193,15 +193,17 @@ public function remove(string $key)
     /**
      * Returns the HTTP header value converted to a date.
      *
+     * @return \DateTimeImmutable|null
+     *
      * @throws \RuntimeException When the HTTP header is not parseable
      */
-    public function getDate(string $key, \DateTime $default = null): ?\DateTimeInterface
+    public function getDate(string $key, \DateTimeInterface $default = null): ?\DateTimeInterface
     {
         if (null === $value = $this->get($key)) {
-            return $default;
+            return null !== $default ? \DateTimeImmutable::createFromInterface($default) : null;
         }
 
-        if (false === $date = \DateTime::createFromFormat(\DATE_RFC2822, $value)) {
+        if (false === $date = \DateTimeImmutable::createFromFormat(\DATE_RFC2822, $value)) {
             throw new \RuntimeException(sprintf('The "%s" HTTP header is not parseable (%s).', $key, $value));
         }
 

Response.php

@@ -687,7 +687,7 @@ public function mustRevalidate(): bool
      *
      * @final
      */
-    public function getDate(): ?\DateTimeInterface
+    public function getDate(): ?\DateTimeImmutable
     {
         return $this->headers->getDate('Date');
     }
@@ -701,10 +701,7 @@ public function getDate(): ?\DateTimeInterface
      */
     public function setDate(\DateTimeInterface $date): static
     {
-        if ($date instanceof \DateTime) {
-            $date = \DateTimeImmutable::createFromMutable($date);
-        }
-
+        $date = \DateTimeImmutable::createFromInterface($date);
         $date = $date->setTimezone(new \DateTimeZone('UTC'));
         $this->headers->set('Date', $date->format('D, d M Y H:i:s').' GMT');
 
@@ -745,13 +742,13 @@ public function expire(): static
      *
      * @final
      */
-    public function getExpires(): ?\DateTimeInterface
+    public function getExpires(): ?\DateTimeImmutable
     {
         try {
             return $this->headers->getDate('Expires');
         } catch (\RuntimeException) {
             // according to RFC 2616 invalid date formats (e.g. "0" and "-1") must be treated as in the past
-            return \DateTime::createFromFormat('U', time() - 172800);
+            return \DateTimeImmutable::createFromFormat('U', time() - 172800);
         }
     }
 
@@ -775,10 +772,7 @@ public function setExpires(\DateTimeInterface $date = null): static
             return $this;
         }
 
-        if ($date instanceof \DateTime) {
-            $date = \DateTimeImmutable::createFromMutable($date);
-        }
-
+        $date = \DateTimeImmutable::createFromInterface($date);
         $date = $date->setTimezone(new \DateTimeZone('UTC'));
         $this->headers->set('Expires', $date->format('D, d M Y H:i:s').' GMT');
 
@@ -934,7 +928,7 @@ public function setClientTtl(int $seconds): static
      *
      * @final
      */
-    public function getLastModified(): ?\DateTimeInterface
+    public function getLastModified(): ?\DateTimeImmutable
     {
         return $this->headers->getDate('Last-Modified');
     }
@@ -959,10 +953,7 @@ public function setLastModified(\DateTimeInterface $date = null): static
             return $this;
         }
 
-        if ($date instanceof \DateTime) {
-            $date = \DateTimeImmutable::createFromMutable($date);
-        }
-
+        $date = \DateTimeImmutable::createFromInterface($date);
         $date = $date->setTimezone(new \DateTimeZone('UTC'));
         $this->headers->set('Last-Modified', $date->format('D, d M Y H:i:s').' GMT');
 

Tests/HeaderBagTest.php

@@ -45,7 +45,7 @@ public function testGetDate()
     {
         $bag = new HeaderBag(['foo' => 'Tue, 4 Sep 2012 20:00:00 +0200']);
         $headerDate = $bag->getDate('foo');
-        $this->assertInstanceOf(\DateTime::class, $headerDate);
+        $this->assertInstanceOf(\DateTimeImmutable::class, $headerDate);
     }
 
     public function testGetDateNull()