synctos/src/loading/sync-function-loader.spec.js

The Syncmaker. A tool to build comprehensive sync functions for Couchbase Sync Gateway.

const path = require('path');
const { expect } = require('chai');
const simpleMock = require('../../lib/simple-mock/index');
const mockRequire = require('mock-require');

describe('Sync function loader', () => {
  let syncFunctionLoader, fsMock, indentMock, fileFragmentLoaderMock, docDefinitionsLoaderMock;

  const expectedMacroName = 'importSyncFunctionFragment';
  const syncFuncTemplateDir = path.resolve(__dirname, '../../templates/sync-function');
  const syncFuncTemplateFile = path.resolve(syncFuncTemplateDir, 'template.js');

  beforeEach(() => {
    // Mock out the "require" calls in the module under test
    fsMock = { readFileSync: simpleMock.stub() };
    mockRequire('fs', fsMock);

    indentMock = { js: simpleMock.stub() };
    mockRequire('../../lib/indent.js/indent.js', indentMock);

    fileFragmentLoaderMock = { load: simpleMock.stub() };
    mockRequire('./file-fragment-loader.js', fileFragmentLoaderMock);

    docDefinitionsLoaderMock = { load: simpleMock.stub() };
    mockRequire('./document-definitions-loader.js', docDefinitionsLoaderMock);

    syncFunctionLoader = mockRequire.reRequire('./sync-function-loader');
  });

  afterEach(() => {
    // Restore "require" calls to their original behaviour after each test case
    mockRequire.stopAll();
  });

  it('should load a sync function as a multi-line JavaScript block', () => {
    validateLoadSuccess(
      'my\n  \r\nfinal\rsync `func`',
      'my\n\nfinal\nsync `func`');
  });

  it('should load a sync function as a JSON string', () => {
    validateLoadSuccess(
      'my\n  \r\n"final"\r`sync` \\func\\',
      '"my\\n\\n\\"final\\"\\n`sync` \\\\func\\\\"',
      { jsonString: true });
  });

  function validateLoadSuccess(indentedSyncFunc, expectedSyncFunc, formatOptions) {
    const docDefinitionsFile = 'my/doc-definitions.js';
    const docDefinitionsContent = 'my-doc-definitions';
    const originalSyncFuncTemplate = 'my-original-sync-fync-template';
    const updatedSyncFuncTemplate = 'function my-sync-func-template() { $DOCUMENT_DEFINITIONS_PLACEHOLDER$; }';

    fsMock.readFileSync.returnWith(originalSyncFuncTemplate);
    fileFragmentLoaderMock.load.returnWith(updatedSyncFuncTemplate);
    docDefinitionsLoaderMock.load.returnWith(docDefinitionsContent);
    indentMock.js.returnWith(indentedSyncFunc);

    const result = syncFunctionLoader.load(docDefinitionsFile, formatOptions);

    expect(result).to.equal(expectedSyncFunc);

    expect(fsMock.readFileSync.callCount).to.equal(1);
    expect(fsMock.readFileSync.calls[0].args).to.eql([ syncFuncTemplateFile, 'utf8' ]);

    expect(fileFragmentLoaderMock.load.callCount).to.equal(1);
    expect(fileFragmentLoaderMock.load.calls[0].args).to.eql([ syncFuncTemplateDir, expectedMacroName, originalSyncFuncTemplate ]);

    expect(docDefinitionsLoaderMock.load.callCount).to.equal(1);
    expect(docDefinitionsLoaderMock.load.calls[0].args).to.eql([ docDefinitionsFile ]);

    expect(indentMock.js.callCount).to.equal(1);
    expect(indentMock.js.calls[0].args).to.eql(
      [ `function my-sync-func-template() { ${docDefinitionsContent}; }`, { tabString: '  ' } ]);
  }
});