Issue #3261847: Add helpful methods to compute the difference between two ComposerUtility objects

package_manager/src/ComposerUtility.php

@@ -155,52 +155,37 @@ class ComposerUtility {
   }
 
   /**
-   * Returns the packages added in another directory.
+   * Returns the packages that are in the current project, but not in another.
    *
    * @param self $other
    *   A Composer utility wrapper around a different directory.
    *
    * @return \Composer\Package\PackageInterface[]
-   *   The packages that were added in the other directory, keyed by name.
+   *   The packages which are installed in the current project, but not in the
+   *   other one, keyed by name.
    */
-  public function getPackagesAddedBy(self $other): array {
-    return array_diff_key(
-      $other->getInstalledPackages(),
-      $this->getInstalledPackages()
-    );
+  public function getPackagesNotIn(self $other): array {
+    return array_diff_key($this->getInstalledPackages(), $other->getInstalledPackages());
   }
 
   /**
-   * Returns the packages that were removed in another directory.
+   * Returns the packages which have a different version in another project.
    *
-   * @param self $other
-   *   A Composer utility wrapper around a different directory.
-   *
-   * @return \Composer\Package\PackageInterface[]
-   *   The packages that were removed in the other directory, keyed by name.
-   */
-  public function getPackagesRemovedBy(self $other): array {
-    return array_diff_key(
-      $this->getInstalledPackages(),
-      $other->getInstalledPackages()
-    );
-  }
-
-  /**
-   * Returns the packages that were updated in another directory.
+   * This compares the current project with another one, and returns packages
+   * which are present in both, but in different versions.
    *
    * @param self $other
    *   A Composer utility wrapper around a different directory.
    *
    * @return \Composer\Package\PackageInterface[]
-   *   The packages in the current directory that were updated in the other
-   *   directory, keyed by name.
+   *   The packages which are present in both the current project and the other
+   *   one, but in different versions, keyed by name.
    */
-  public function getPackagesUpdatedBy(self $other): array {
-    $mine = $this->getInstalledPackages();
+  public function getPackagesWithDifferentVersionsIn(self $other): array {
     $theirs = $other->getInstalledPackages();
 
-    $packages = array_intersect_key($mine, $theirs);
+    // Only compare packages that are both here and there.
+    $packages = array_intersect_key($this->getInstalledPackages(), $theirs);
 
     $filter = function (PackageInterface $package, string $name) use ($theirs): bool {
       return Comparator::notEqualTo($package->getVersion(), $theirs[$name]->getVersion());