feat: Use PermissionReaders to determine available permissions

These readers will determine which permissions
are available for the incoming credentials.
Their results then get combined in a UnionReader
and authorized in a PermissionBasedAuthorizer

test/unit/authorization/AllStaticReader.test.ts

@@ -0,0 +1,34 @@
+import { CredentialGroup } from '../../../src/authentication/Credentials';
+import { AllStaticReader } from '../../../src/authorization/AllStaticReader';
+import type { Permission } from '../../../src/ldp/permissions/Permissions';
+
+function getPermissions(allow: boolean): Permission {
+  return {
+    read: allow,
+    write: allow,
+    append: allow,
+    control: allow,
+  };
+}
+
+describe('An AllStaticReader', (): void => {
+  const credentials = { [CredentialGroup.agent]: {}, [CredentialGroup.public]: undefined };
+  const identifier = { path: 'http://test.com/resource' };
+
+  it('can handle everything.', async(): Promise<void> => {
+    const authorizer = new AllStaticReader(true);
+    await expect(authorizer.canHandle({} as any)).resolves.toBeUndefined();
+  });
+
+  it('always returns permissions matching the given allow parameter.', async(): Promise<void> => {
+    let authorizer = new AllStaticReader(true);
+    await expect(authorizer.handle({ credentials, identifier })).resolves.toEqual({
+      [CredentialGroup.agent]: getPermissions(true),
+    });
+
+    authorizer = new AllStaticReader(false);
+    await expect(authorizer.handle({ credentials, identifier })).resolves.toEqual({
+      [CredentialGroup.agent]: getPermissions(false),
+    });
+  });
+});