fix(core): cannot determine packaging when bundling that produces an archive is skipped

packages/@aws-cdk/core/lib/asset-staging.ts

@@ -336,6 +336,15 @@ export class AssetStaging extends CoreConstruct {
     const stagedPath = path.resolve(this.assetOutdir, renderAssetFilename(assetHash, bundledAsset.extension));
 
     this.stageAsset(bundledAsset.path, stagedPath, 'move');
+
+    // If bundling produced a single archive file we "touch" this file in the bundling
+    // directory after it has been moved to the staging directory. This way if bundling
+    // is skipped because the bundling directory already exists we can still determine
+    // the correct packaging type.
+    if (bundledAsset.packaging === FileAssetPackaging.FILE) {
+      fs.closeSync(fs.openSync(bundledAsset.path, 'w'));
+    }
+
     return {
       assetHash,
       stagedPath,

packages/@aws-cdk/core/test/staging.test.ts

@@ -887,20 +887,70 @@ nodeunitShim({
     // THEN
     const assembly = app.synth();
     test.deepEqual(fs.readdirSync(assembly.directory), [
-      'asset.f43148c61174f444925231b5849b468f21e93b5d1469cd07c53625ffd039ef48', // this is the bundle dir but it's empty
+      'asset.f43148c61174f444925231b5849b468f21e93b5d1469cd07c53625ffd039ef48', // this is the bundle dir
       'asset.f43148c61174f444925231b5849b468f21e93b5d1469cd07c53625ffd039ef48.zip',
       'cdk.out',
       'manifest.json',
       'stack.template.json',
       'tree.json',
     ]);
-    test.equal(fs.readdirSync(path.join(assembly.directory, 'asset.f43148c61174f444925231b5849b468f21e93b5d1469cd07c53625ffd039ef48')).length, 0); // empty bundle dir
+    test.deepEqual(fs.readdirSync(path.join(assembly.directory, 'asset.f43148c61174f444925231b5849b468f21e93b5d1469cd07c53625ffd039ef48')), [
+      'test.zip', // bundle dir with "touched" bundled output file
+    ]);
     test.deepEqual(staging.packaging, FileAssetPackaging.FILE);
     test.deepEqual(staging.isArchive, true);
 
     test.done();
   },
 
+  'bundling that produces a single archive file with disk cache'(test: Test) {
+    // GIVEN
+    const TEST_OUTDIR = path.join(__dirname, 'cdk.out');
+    if (fs.existsSync(TEST_OUTDIR)) {
+      fs.removeSync(TEST_OUTDIR);
+    }
+
+    const directory = path.join(__dirname, 'fs', 'fixtures', 'test1');
+
+    const app1 = new App({ outdir: TEST_OUTDIR });
+    const stack1 = new Stack(app1, 'Stack');
+
+    const app2 = new App({ outdir: TEST_OUTDIR }); // same OUTDIR
+    const stack2 = new Stack(app2, 'stack');
+
+    // WHEN
+    const staging1 = new AssetStaging(stack1, 'Asset', {
+      sourcePath: directory,
+      bundling: {
+        image: BundlingDockerImage.fromRegistry('alpine'),
+        command: [DockerStubCommand.SINGLE_ARCHIVE],
+        outputType: BundlingOutput.ARCHIVED,
+      },
+    });
+
+    // Now clear asset hash cache to show that during the second staging
+    // even though bundling is skipped it will correctly be considered
+    // as a FileAssetPackaging.FILE.
+    AssetStaging.clearAssetHashCache();
+
+    const staging2 = new AssetStaging(stack2, 'Asset', {
+      sourcePath: directory,
+      bundling: {
+        image: BundlingDockerImage.fromRegistry('alpine'),
+        command: [DockerStubCommand.SINGLE_ARCHIVE],
+        outputType: BundlingOutput.ARCHIVED,
+      },
+    });
+
+    // THEN
+    test.deepEqual(staging1.packaging, FileAssetPackaging.FILE);
+    test.deepEqual(staging1.isArchive, true);
+    test.deepEqual(staging2.packaging, staging1.packaging);
+    test.deepEqual(staging2.isArchive, staging1.isArchive);
+
+    test.done();
+  },
+
   'bundling that produces a single archive file with NOT_ARCHIVED'(test: Test) {
     // GIVEN
     const app = new App();