Issue #3283498 by Mile23, alexpott: Scaffold ReplaceOp::copyScaffold() throws...

Issue #3283498 by Mile23, alexpott: Scaffold ReplaceOp::copyScaffold() throws an error for empty files

composer/Plugin/Scaffold/Operations/ReplaceOp.php

@@ -92,8 +92,7 @@ public function process(ScaffoldFilePath $destination, IOInterface $io, Scaffold
   protected function copyScaffold(ScaffoldFilePath $destination, IOInterface $io) {
     $interpolator = $destination->getInterpolator();
     $this->source->addInterpolationData($interpolator);
-    $success = file_put_contents($destination->fullPath(), $this->contents());
-    if (!$success) {
+    if (file_put_contents($destination->fullPath(), $this->contents()) === FALSE) {
       throw new \RuntimeException($interpolator->interpolate("Could not copy source file <info>[src-rel-path]</info> to <info>[dest-rel-path]</info>!"));
     }
     $io->write($interpolator->interpolate("  - Copy <info>[dest-rel-path]</info> from <info>[src-rel-path]</info>"));

core/tests/Drupal/Tests/Composer/Plugin/Scaffold/Integration/ReplaceOpTest.php

@@ -39,4 +39,26 @@ public function testProcess() {
     $this->assertStringContainsString('Copy [web-root]/robots.txt from assets/robots.txt', $output);
   }
 
+  /**
+   * @covers ::process
+   */
+  public function testEmptyFile() {
+    $fixtures = new Fixtures();
+    $destination = $fixtures->destinationPath('[web-root]/empty_file.txt');
+    $source = $fixtures->sourcePath('empty-file', 'empty_file.txt');
+    $options = ScaffoldOptions::create([]);
+    $sut = new ReplaceOp($source, TRUE);
+    // Assert that there is no target file before we run our test.
+    $this->assertFileDoesNotExist($destination->fullPath());
+    // Test the system under test.
+    $sut->process($destination, $fixtures->io(), $options);
+    // Assert that the target file was created.
+    $this->assertFileExists($destination->fullPath());
+    // Assert the target contained the contents from the correct scaffold file.
+    $this->assertSame('', file_get_contents($destination->fullPath()));
+    // Confirm that expected output was written to our io fixture.
+    $output = $fixtures->getOutput();
+    $this->assertStringContainsString('Copy [web-root]/empty_file.txt from assets/empty_file.txt', $output);
+  }
+
 }

core/tests/Drupal/Tests/Composer/Plugin/Scaffold/fixtures/empty-file/composer.json

+{
+  "name": "fixtures/empty-file",
+  "extra": {
+    "drupal-scaffold": {
+      "file-mapping": {
+        "[web-root]/empty_file.txt": "assets/empty_file.txt"
+      }
+    }
+  }
+}