Install older PHP versions via alternate tap

Fixes #1407

Homebrew's support policy now aggressively disables older versions earlier than it did previously.
That is why we tap the `shivammathur/php` repository.

But since Homebrew also now "keeps" those old formulae but marks them as disabled, when Valet runs `brew install [email protected]` it fails because Homebrew just aborts due to its flags in the outdated formula.
(They mark it as "disabled" and/or "keg_only :versioned_formula", but don't actually delete the formula from their repository.)
To override that we must use `brew install shivammathur/php/[email protected]` internally.

Therefore, we need to maintain a list of which PHP Versions we wish to specifically prefix with the `shivammathur/php` tap in order to bypass Homebrew's flags.

**ANNUAL MAINTENANCE**
1. This PR adds the array of `LIMITED_PHP_VERSIONS` which we will have to update annually when new PHP versions are retired as others are released.
2. We should also annually update the `LATEST_PHP_VERSION` string.

Author: drbyte

cli/Valet/Brew.php

@@ -8,6 +8,7 @@
 
 class Brew
 {
+    // This is the array of PHP versions that Valet will attempt to install/configure when requested
     const SUPPORTED_PHP_VERSIONS = [
         'php',
         '[email protected]',
@@ -19,9 +20,22 @@ class Brew
         '[email protected]',
     ];
 
-    const BREW_DISABLE_AUTO_CLEANUP = 'HOMEBREW_NO_INSTALL_CLEANUP=1';
+    // Update this LATEST and the following LIMITED array when PHP versions are released or retired
+    // We specify a numbered version here even though Homebrew links its generic 'php' alias to it
+    const LATEST_PHP_VERSION = '[email protected]';
 
-    const LATEST_PHP_VERSION = '[email protected]';
+    // These are the PHP versions that should be installed via the shivammathur/php tap because
+    // Homebrew officially no longer bottles them or they're marked disabled in their formula
+    // Cue: Homebrew reports "[email protected] has been disabled because it is a versioned formula"
+    const LIMITED_PHP_VERSIONS = [
+        '[email protected]',
+        '[email protected]',
+        '[email protected]',
+        '[email protected]',
+        '[email protected]',
+    ];
+
+    const BREW_DISABLE_AUTO_CLEANUP = 'HOMEBREW_NO_INSTALL_CLEANUP=1';
 
     public function __construct(public CommandLine $cli, public Filesystem $files)
     {
@@ -72,6 +86,14 @@ public function supportedPhpVersions(): Collection
         return collect(static::SUPPORTED_PHP_VERSIONS);
     }
 
+    /**
+     * Get a list of disabled/limited PHP versions.
+     */
+    public function limitedPhpVersions(): Collection
+    {
+        return collect(static::LIMITED_PHP_VERSIONS);
+    }
+
     /**
      * Get a list of installed PHP formulae.
      */
@@ -135,7 +157,9 @@ public function installOrFail(string $formula, array $options = [], array $taps
         }
 
         output('<info>['.$formula.'] is not installed, installing it now via Brew...</info> 🍻');
-        if ($formula !== 'php' && starts_with($formula, 'php') && preg_replace('/[^\d]/', '', $formula) < '73') {
+
+        if ($this->limitedPhpVersions()->contains($formula)) {
+            $formula = 'shivammathur/php/' . $formula;
             warning('Note: older PHP versions may take 10+ minutes to compile from source. Please wait ...');
         }
 

tests/BrewTest.php

@@ -203,6 +203,22 @@ public function test_linked_php_throws_exception_if_unsupported_php_version_is_l
         resolve(Brew::class)->linkedPhp();
     }
 
+    public function test_outdated_php_versions_use_the_alternate_tap()
+    {
+        $brewMock = Mockery::mock(Brew::class, [
+            $cli = Mockery::mock(CommandLine::class),
+            Mockery::mock(Filesystem::class),
+        ])->makePartial();
+
+        $brewMock->shouldReceive('limitedPhpVersions')->andReturn(collect([
+            '[email protected]',
+        ]));
+
+        $cli->shouldReceive('runAsUser')->once()->with(Brew::BREW_DISABLE_AUTO_CLEANUP.' brew install shivammathur/php/[email protected]', Mockery::type('Closure'));
+
+        $brewMock->installOrFail('[email protected]');
+    }
+
     public function test_install_or_fail_will_install_brew_formulae()
     {
         $cli = Mockery::mock(CommandLine::class);