fix(@angular-devkit/core): fix cannot delete directory

Author: Teamop

Diff for: packages/angular_devkit/core/src/virtual-fs/host/memory.ts

@@ -180,7 +180,7 @@ export class SimpleMemoryHost implements Host<{}> {
     path = this._toAbsolute(path);
     if (this._isDirectory(path)) {
       for (const [cachePath] of this._cache.entries()) {
-        if (path.startsWith(cachePath + NormalizedSep)) {
+        if (cachePath.startsWith(path + NormalizedSep) || cachePath === path) {
           this._cache.delete(cachePath);
         }
       }

Diff for: packages/angular_devkit/core/src/virtual-fs/host/memory_spec.ts

@@ -65,6 +65,22 @@ describe('SimpleMemoryHost', () => {
     expect(host.exists(normalize('/sub/file1'))).toBe(false);
   });
 
+  it('can delete directory', () => {
+    const host = new SyncDelegateHost(new SimpleMemoryHost());
+
+    const buffer = stringToFileBuffer('hello');
+
+    expect(host.exists(normalize('/sub/file1'))).toBe(false);
+    host.write(normalize('/sub/file1'), buffer);
+    host.write(normalize('/subfile.2'), buffer);
+    expect(host.exists(normalize('/sub/file1'))).toBe(true);
+    expect(host.exists(normalize('/subfile.2'))).toBe(true);
+    host.delete(normalize('/sub'));
+    expect(host.exists(normalize('/sub/file1'))).toBe(false);
+    expect(host.exists(normalize('/sub'))).toBe(false);
+    expect(host.exists(normalize('/subfile.2'))).toBe(true);
+  });
+
   it('can rename', () => {
     const host = new SyncDelegateHost(new SimpleMemoryHost());