Make sure ignore strategies receive directories with trailing slash

ignore strategies like git, expect directories to be passed in with a
trailing slash in order to properly match.

consider a source tree:

├── hello
│   └── index.html
├── index.html

now we want to exclude everything except all html files
(including all subdirectories).

this can be done with a gitignore of:
*
!*/
!*.html

in order for the git ignore strategy to properly match this,
it needs to know that hello is a directory.

this patch just does that by appending a trailing slash for the
ignore strategies.

Author: danilobuerger

packages/@aws-cdk/core/lib/fs/copy.ts

@@ -15,15 +15,16 @@ export function copyDirectory(srcDir: string, destDir: string, options: CopyOpti
     throw new Error(`${srcDir} is not a directory`);
   }
 
-  const files = fs.readdirSync(srcDir);
+  const files = fs.readdirSync(srcDir, { withFileTypes: true });
   for (const file of files) {
-    const sourceFilePath = path.join(srcDir, file);
+    const sourceFilePath = path.join(srcDir, file.name);
 
-    if (ignoreStrategy.ignores(sourceFilePath)) {
+    const ignorePath = sourceFilePath + (file.name && file.isDirectory() ? path.sep : '');
+    if (ignoreStrategy.ignores(ignorePath)) {
       continue;
     }
 
-    const destFilePath = path.join(destDir, file);
+    const destFilePath = path.join(destDir, file.name);
 
     let stat: fs.Stats | undefined = follow === SymlinkFollowMode.ALWAYS
       ? fs.statSync(sourceFilePath)

packages/@aws-cdk/core/lib/fs/ignore.ts

@@ -117,6 +117,9 @@ export class GlobIgnoreStrategy extends IgnoreStrategy {
     }
 
     let relativePath = path.relative(this.absoluteRootPath, absoluteFilePath);
+    if (relativePath) {
+      relativePath += absoluteFilePath.endsWith(path.sep) ? path.sep : '';
+    }
     let excludeOutput = false;
 
     for (const pattern of this.patterns) {
@@ -174,6 +177,9 @@ export class GitIgnoreStrategy extends IgnoreStrategy {
     }
 
     let relativePath = path.relative(this.absoluteRootPath, absoluteFilePath);
+    if (relativePath) {
+      relativePath += absoluteFilePath.endsWith(path.sep) ? path.sep : '';
+    }
 
     return this.ignore.ignores(relativePath);
   }
@@ -217,6 +223,9 @@ export class DockerIgnoreStrategy extends IgnoreStrategy {
     }
 
     let relativePath = path.relative(this.absoluteRootPath, absoluteFilePath);
+    if (relativePath) {
+      relativePath += absoluteFilePath.endsWith(path.sep) ? path.sep : '';
+    }
 
     return this.ignore.ignores(relativePath);
   }