fix build, migrate test backend

packages/netlify-cms-backend-github/src/__tests__/API.spec.js

@@ -0,0 +1,38 @@
+import API from "../API";
+
+describe('github API', () => {
+  const mockAPI = (api, responses) => {
+    api.request = (path, options = {}) => {
+      const normalizedPath = path.indexOf('?') !== -1 ? path.substr(0, path.indexOf('?')) : path;
+      const response = responses[normalizedPath];
+      return typeof response === 'function'
+        ? Promise.resolve(response(options))
+        : Promise.reject(new Error(`No response for path '${normalizedPath}'`))
+    };
+  }
+
+  it('should create PR with correct base branch name when publishing with editorial workflow', () => {
+    let prBaseBranch = null;
+    const api = new API({ branch: 'gh-pages', repo: 'my-repo' });
+    const responses = {
+      '/repos/my-repo/branches/gh-pages': () => ({ commit: { sha: 'def' } }),
+      '/repos/my-repo/git/trees/def': () => ({ tree: [] }),
+      '/repos/my-repo/git/trees': () => ({}),
+      '/repos/my-repo/git/commits': () => ({}),
+      '/repos/my-repo/git/refs': () => ({}),
+      '/repos/my-repo/pulls': (pullRequest) => {
+        prBaseBranch = JSON.parse(pullRequest.body).base;
+        return { head: { sha: 'cbd' } };
+      },
+      '/user': () => ({}),
+      '/repos/my-repo/git/blobs': () => ({}),
+      '/repos/my-repo/git/refs/meta/_netlify_cms': () => ({ 'object': {} })
+    };
+    mockAPI(api, responses);
+
+    return expect(
+      api.editorialWorkflowGit(null, { slug: 'entry', sha: 'abc' }, null, {})
+        .then(() => prBaseBranch)
+    ).resolves.toEqual('gh-pages')
+  });
+});