bug #62562 [Console] don't discard existing aliases when constructing Command (henderkes)

This PR was squashed before being merged into the 7.4 branch.

Discussion
----------

[Console] don't discard existing aliases when constructing Command

| Q             | A
| ------------- | ---
| Branch?       | 7.4
| Bug fix?      | yes
| New feature?  no
| Deprecations? | no
| Issues        | Fix #62557
| License       | MIT

<!--
🛠️ Replace this text with a concise explanation of your change:
- What it does and why it's needed
- A simple example of how it works (include PHP, YAML, etc.)
- If it modifies existing behavior, include a before/after comparison

The code in #62557 was broken by 5e7cd96. Here I combine the new aliases found by pipes in the string with existing ones that may have previously been set.
-->

Contributor guidelines:
- [x] Add tests and ensure they pass
- [x] Bug fixes must target the **lowest maintained** branch where they apply
  https://symfony.com/releases#maintained-symfony-branches
- [x] New features and deprecations must target the **feature** branch
  and must add an entry to the changelog file of the patched component:
  https://symfony.com/doc/current/contributing/code/conventions.html#writing-a-changelog-entry
- [x] Do not break backward compatibility:
  https://symfony.com/bc

Commits
-------

917d8d0c129 [Console] don't discard existing aliases when constructing Command

Author: chalasr

Command/Command.php

@@ -120,6 +120,12 @@ public function __construct(?string $name = null, ?callable $code = null)
                 $name = array_shift($aliases);
             }
 
+            // we must not overwrite existing aliases, combine new ones with existing ones
+            $aliases = array_unique([
+                ...$this->aliases,
+                ...$aliases,
+            ]);
+
             $this->setAliases($aliases);
         }
 

Tests/Command/CommandTest.php

@@ -199,12 +199,25 @@ public function testGetProcessedHelp()
     public function testGetSetAliases()
     {
         $command = new \TestCommand();
-        $this->assertEquals(['name'], $command->getAliases(), '->getAliases() returns the aliases');
         $ret = $command->setAliases(['name1']);
         $this->assertEquals($command, $ret, '->setAliases() implements a fluent interface');
         $this->assertEquals(['name1'], $command->getAliases(), '->setAliases() sets the aliases');
     }
 
+    public function testAliasesSetBeforeParentConstructorArePreserved()
+    {
+        $command = new class extends Command {
+            public function __construct()
+            {
+                // set aliases before calling parent constructor
+                $this->setAliases(['existingalias']);
+                parent::__construct('foo|newalias');
+            }
+        };
+
+        $this->assertSame(['existingalias', 'newalias'], $command->getAliases(), 'Aliases set before parent::__construct() must be preserved.');
+    }
+
     #[TestWith(['name|alias1|alias2', 'name', ['alias1', 'alias2'], false])]
     #[TestWith(['|alias1|alias2', 'alias1', ['alias2'], true])]
     public function testSetAliasesAndHiddenViaName(string $name, string $expectedName, array $expectedAliases, bool $expectedHidden)