[10.x] Add hasPackage method to Composer class (#48124)

* Update composer.json

* extract logic for locating the composer.json file

* formatting

---------

Co-authored-by: Taylor Otwell <[email protected]>

Author: emargareten

src/Illuminate/Support/Composer.php

@@ -38,6 +38,22 @@ public function __construct(Filesystem $files, $workingPath = null)
         $this->workingPath = $workingPath;
     }
 
+    /**
+     * Determine if the given Composer package is installed.
+     *
+     * @param  string  $package
+     * @return bool
+     *
+     * @throw \RuntimeException
+     */
+    protected function hasPackage($package)
+    {
+        $composer = json_decode(file_get_contents($this->findComposerFile()), true);
+
+        return array_key_exists($package, $composer['require'] ?? [])
+            || array_key_exists($package, $composer['require-dev'] ?? []);
+    }
+
     /**
      * Install the given Composer packages into the application.
      *
@@ -104,11 +120,7 @@ public function removePackages(array $packages, bool $dev = false, Closure|Outpu
      */
     public function modify(callable $callback)
     {
-        $composerFile = "{$this->workingPath}/composer.json";
-
-        if (! file_exists($composerFile)) {
-            throw new RuntimeException("Unable to locate `composer.json` file at [{$this->workingPath}].");
-        }
+        $composerFile = $this->findComposerFile();
 
         $composer = json_decode(file_get_contents($composerFile), true, 512, JSON_THROW_ON_ERROR);
 
@@ -147,7 +159,7 @@ public function dumpOptimized()
     }
 
     /**
-     * Get the composer command for the environment.
+     * Get the Composer binary / command for the environment.
      *
      * @return array
      */
@@ -160,6 +172,24 @@ public function findComposer()
         return ['composer'];
     }
 
+    /**
+     * Get the path to the "composer.json" file.
+     *
+     * @return string
+     *
+     * @throw \RuntimeException
+     */
+    protected function findComposerFile()
+    {
+        $composerFile = "{$this->workingPath}/composer.json";
+
+        if (! file_exists($composerFile)) {
+            throw new RuntimeException("Unable to locate `composer.json` file at [{$this->workingPath}].");
+        }
+
+        return $composerFile;
+    }
+
     /**
      * Get the PHP binary.
      *