MAGETWO-51544: [Github] Cannot upgrade to Magento 2.0.4 #4013

- Code review comment update.
- Consider ["extra"]["map"] section absence in base package a valid scenario

Author: ark99

setup/src/Magento/Setup/Model/PathBuilder.php

@@ -45,6 +45,7 @@ public function build()
         // Locate composer.json for magento2-base module and read the extra map section for the list of
         // magento specific files and directories that updater will need access to perform the upgrade
 
+        $filesPathList = [];
         $vendorDir = require VENDOR_PATH;
         $basePackageComposerFilePath = $vendorDir . '/' . self::MAGENTO_BASE_PACKAGE_COMPOSER_JSON_FILE;
         if (!$this->reader->isExist($basePackageComposerFilePath)) {
@@ -59,17 +60,12 @@ public function build()
         }
         $composerJsonFileData = json_decode($this->reader->readFile($basePackageComposerFilePath), true);
         if (!isset($composerJsonFileData[self::COMPOSER_KEY_EXTRA][self::COMPOSER_KEY_MAP])) {
-            throw new \Magento\Setup\Exception(
-                'Could not find "extra" => "map" section within '
-                . self::MAGENTO_BASE_PACKAGE_COMPOSER_JSON_FILE
-                . ' file.'
-            );
+            return $filesPathList;
         }
         $extraMappings = $composerJsonFileData[self::COMPOSER_KEY_EXTRA][self::COMPOSER_KEY_MAP];
-        $fileAndPathList = [];
         foreach ($extraMappings as $map) {
-            $fileAndPathList[] = $map[1];
+            $filesPathList[] = $map[1];
         }
-        return $fileAndPathList;
+        return $filesPathList;
     }
 }

setup/src/Magento/Setup/Test/Unit/Model/PathBuilderTest.php

@@ -70,7 +70,7 @@ public function testBuildComposerJsonFileNotReadable()
         $this->pathBuilder->build();
     }
 
-    // Error scenario: ["extra"]["map"] is absent within magento/magento2-base/composer.json file
+    // Scenario: ["extra"]["map"] is absent within magento/magento2-base/composer.json file
     public function testBuildNoExtraMapSectionInComposerJsonFile()
     {
         $this->readerMock->expects($this->once())->method('isExist')->willReturn(true);
@@ -85,14 +85,9 @@ public function testBuildNoExtraMapSectionInComposerJsonFile()
             ]
         );
         $this->readerMock->expects($this->once())->method('readFile')->willReturn($jsonData);
-        $this->setExpectedException(
-            'Magento\Setup\Exception',
-            sprintf(
-                'Could not find "extra" => "map" section within %s file.',
-                PathBuilder::MAGENTO_BASE_PACKAGE_COMPOSER_JSON_FILE
-            )
-        );
-        $this->pathBuilder->build();
+        $expectedList = [];
+        $actualList = $this->pathBuilder->build();
+        $this->assertEquals($expectedList, $actualList);
     }
 
     // Success scenario