feat: Convert data from ResourceStore based on preferences

test/unit/storage/RepresentationConvertingStore.test.ts

@@ -0,0 +1,60 @@
+import { RepresentationConverter } from '../../../src/storage/conversion/RepresentationConverter';
+import { RepresentationConvertingStore } from '../../../src/storage/RepresentationConvertingStore';
+import { ResourceStore } from '../../../src/storage/ResourceStore';
+
+describe('A RepresentationConvertingStore', (): void => {
+  let store: RepresentationConvertingStore;
+  let source: ResourceStore;
+  let handleSafeFn: jest.Mock<Promise<void>, []>;
+  let converter: RepresentationConverter;
+
+  beforeEach(async(): Promise<void> => {
+    source = {
+      getRepresentation: jest.fn(async(): Promise<any> => ({ data: 'data', metadata: { contentType: 'text/turtle' }})),
+    } as unknown as ResourceStore;
+
+    handleSafeFn = jest.fn(async(): Promise<any> => 'converter');
+    converter = { handleSafe: handleSafeFn } as unknown as RepresentationConverter;
+
+    store = new RepresentationConvertingStore(source, converter);
+  });
+
+  it('returns the Representation from the source if no changes are required.', async(): Promise<void> => {
+    await expect(store.getRepresentation({ path: 'path' }, { type: [
+      { value: 'text/*', weight: 0 }, { value: 'text/turtle', weight: 1 },
+    ]})).resolves.toEqual({
+      data: 'data',
+      metadata: { contentType: 'text/turtle' },
+    });
+    expect(source.getRepresentation).toHaveBeenCalledTimes(1);
+    expect(source.getRepresentation).toHaveBeenLastCalledWith(
+      { path: 'path' }, { type: [{ value: 'text/*', weight: 0 }, { value: 'text/turtle', weight: 1 }]}, undefined,
+    );
+    expect(handleSafeFn).toHaveBeenCalledTimes(0);
+  });
+
+  it('returns the Representation from the source if there are no preferences.', async(): Promise<void> => {
+    await expect(store.getRepresentation({ path: 'path' }, {})).resolves.toEqual({
+      data: 'data',
+      metadata: { contentType: 'text/turtle' },
+    });
+    expect(source.getRepresentation).toHaveBeenCalledTimes(1);
+    expect(source.getRepresentation).toHaveBeenLastCalledWith(
+      { path: 'path' }, {}, undefined,
+    );
+    expect(handleSafeFn).toHaveBeenCalledTimes(0);
+  });
+
+  it('calls the converter if another output is preferred.', async(): Promise<void> => {
+    await expect(store.getRepresentation({ path: 'path' }, { type: [
+      { value: 'text/plain', weight: 1 }, { value: 'text/turtle', weight: 0 },
+    ]})).resolves.toEqual('converter');
+    expect(source.getRepresentation).toHaveBeenCalledTimes(1);
+    expect(handleSafeFn).toHaveBeenCalledTimes(1);
+    expect(handleSafeFn).toHaveBeenLastCalledWith({
+      identifier: { path: 'path' },
+      representation: { data: 'data', metadata: { contentType: 'text/turtle' }},
+      preferences: { type: [{ value: 'text/plain', weight: 1 }, { value: 'text/turtle', weight: 0 }]},
+    });
+  });
+});