feat: Create SubdomainIdentifierStrategy

This strategy interprets all subdomains of the base to also be root containers.

test/unit/util/identifiers/BaseIdentifierStrategy.test.ts

@@ -0,0 +1,31 @@
+import type { ResourceIdentifier } from '../../../../src/ldp/representation/ResourceIdentifier';
+import { BaseIdentifierStrategy } from '../../../../src/util/identifiers/BaseIdentifierStrategy';
+
+class DummyStrategy extends BaseIdentifierStrategy {
+  public supportsIdentifier(identifier: ResourceIdentifier): boolean {
+    return !identifier.path.endsWith('unsupported');
+  }
+
+  public isRootContainer(identifier: ResourceIdentifier): boolean {
+    return identifier.path.endsWith('root');
+  }
+}
+
+describe('A BaseIdentifierStrategy', (): void => {
+  const strategy = new DummyStrategy();
+
+  it('returns the parent identifier.', async(): Promise<void> => {
+    expect(strategy.getParentContainer({ path: 'http://test.com/foo/bar' })).toEqual({ path: 'http://test.com/foo/' });
+    expect(strategy.getParentContainer({ path: 'http://test.com/foo/bar/' })).toEqual({ path: 'http://test.com/foo/' });
+  });
+
+  it('errors when attempting to get the parent of an unsupported identifier.', async(): Promise<void> => {
+    expect((): any => strategy.getParentContainer({ path: '/unsupported' }))
+      .toThrow('/unsupported is not supported');
+  });
+
+  it('errors when attempting to get the parent of a root container.', async(): Promise<void> => {
+    expect((): any => strategy.getParentContainer({ path: 'http://test.com/root' }))
+      .toThrow('http://test.com/root is a root container and has no parent');
+  });
+});