Handle empty-repo state after the first commit

Moved getBranchData() out of Project actions. This action has to
be shared between both Project and Commit module, hence it needs
to be available from the top-level actions in IDE

Provide a dummy bootstrapping for a non-existent branch when setting
workingReference

When committing to an empty repo, fetch the branch information right
after the very first commit to set a proper reference on state

11 files changed, 223 insertions, 135 deletions

diff --git a/app/assets/javascripts/ide/stores/actions.js b/app/assets/javascripts/ide/stores/actions.js
index 7b660bda081..10e9bb272f9 100644
--- a/app/assets/javascripts/ide/stores/actions.js
+++ b/app/assets/javascripts/ide/stores/actions.js
@@ -1,10 +1,12 @@
 import $ from 'jquery';
 import Vue from 'vue';
+import { __ } from '~/locale';
 import { visitUrl } from '~/lib/utils/url_utility';
 import flash from '~/flash';
 import * as types from './mutation_types';
 import { decorateFiles } from '../lib/files';
 import { stageKeys } from '../constants';
+import service from '../services';
 
 export const redirectToUrl = (_, url) => visitUrl(url);
 
@@ -237,6 +239,45 @@ export const renameEntry = (
   }
 };
 
+export const getBranchData = ({ commit, state }, { projectId, branchId, force = false } = {}) =>
+  new Promise((resolve, reject) => {
+    if (
+      typeof state.projects[`${projectId}`] === 'undefined' ||
+      !state.projects[`${projectId}`].branches[branchId] ||
+      force
+    ) {
+      service
+        .getBranchData(`${projectId}`, branchId)
+        .then(({ data }) => {
+          const { id } = data.commit;
+          commit(types.SET_BRANCH, {
+            projectPath: `${projectId}`,
+            branchName: branchId,
+            branch: data,
+          });
+          commit(types.SET_BRANCH_WORKING_REFERENCE, { projectId, branchId, reference: id });
+          resolve(data);
+        })
+        .catch(e => {
+          if (e.response.status === 404) {
+            reject(e);
+          } else {
+            flash(
+              __('Error loading branch data. Please try again.'),
+              'alert',
+              document,
+              null,
+              false,
+              true,
+            );
+            reject(new Error(`Branch not loaded - ${projectId}/${branchId}`));
+          }
+        });
+    } else {
+      resolve(state.projects[`${projectId}`].branches[branchId]);
+    }
+  });
+
 export * from './actions/tree';
 export * from './actions/file';
 export * from './actions/project';
diff --git a/app/assets/javascripts/ide/stores/actions/project.js b/app/assets/javascripts/ide/stores/actions/project.js
index 081a8ee10f8..b9c600c93cd 100644
--- a/app/assets/javascripts/ide/stores/actions/project.js
+++ b/app/assets/javascripts/ide/stores/actions/project.js
@@ -35,45 +35,6 @@ export const getProjectData = ({ commit, state }, { namespace, projectId, force
     }
   });
 
-export const getBranchData = ({ commit, state }, { projectId, branchId, force = false } = {}) =>
-  new Promise((resolve, reject) => {
-    if (
-      typeof state.projects[`${projectId}`] === 'undefined' ||
-      !state.projects[`${projectId}`].branches[branchId] ||
-      force
-    ) {
-      service
-        .getBranchData(`${projectId}`, branchId)
-        .then(({ data }) => {
-          const { id } = data.commit;
-          commit(types.SET_BRANCH, {
-            projectPath: `${projectId}`,
-            branchName: branchId,
-            branch: data,
-          });
-          commit(types.SET_BRANCH_WORKING_REFERENCE, { projectId, branchId, reference: id });
-          resolve(data);
-        })
-        .catch(e => {
-          if (e.response.status === 404) {
-            reject(e);
-          } else {
-            flash(
-              __('Error loading branch data. Please try again.'),
-              'alert',
-              document,
-              null,
-              false,
-              true,
-            );
-            reject(new Error(`Branch not loaded - ${projectId}/${branchId}`));
-          }
-        });
-    } else {
-      resolve(state.projects[`${projectId}`].branches[branchId]);
-    }
-  });
-
 export const refreshLastCommitData = ({ commit }, { projectId, branchId } = {}) =>
   service
     .getBranchData(projectId, branchId)
diff --git a/app/assets/javascripts/ide/stores/actions/tree.js b/app/assets/javascripts/ide/stores/actions/tree.js
index 3d83e4a9ba5..75511574d3e 100644
--- a/app/assets/javascripts/ide/stores/actions/tree.js
+++ b/app/assets/javascripts/ide/stores/actions/tree.js
@@ -74,17 +74,13 @@ export const getFiles = ({ state, commit, dispatch }, { projectId, branchId } =
           resolve();
         })
         .catch(e => {
-          if (e.response.status === 404) {
-            dispatch('showBranchNotFoundError', branchId);
-          } else {
-            dispatch('setErrorMessage', {
-              text: __('An error occurred whilst loading all the files.'),
-              action: payload =>
-                dispatch('getFiles', payload).then(() => dispatch('setErrorMessage', null)),
-              actionText: __('Please try again'),
-              actionPayload: { projectId, branchId },
-            });
-          }
+          dispatch('setErrorMessage', {
+            text: __('An error occurred whilst loading all the files.'),
+            action: payload =>
+              dispatch('getFiles', payload).then(() => dispatch('setErrorMessage', null)),
+            actionText: __('Please try again'),
+            actionPayload: { projectId, branchId },
+          });
           reject(e);
         });
     } else {
diff --git a/app/assets/javascripts/ide/stores/modules/commit/actions.js b/app/assets/javascripts/ide/stores/modules/commit/actions.js
index c2760eb1554..1fd319adbdb 100644
--- a/app/assets/javascripts/ide/stores/modules/commit/actions.js
+++ b/app/assets/javascripts/ide/stores/modules/commit/actions.js
@@ -135,6 +135,17 @@ export const commitChanges = ({ commit, state, getters, dispatch, rootState, roo
         return null;
       }
 
+      if (!data.parent_ids.length) {
+        dispatch(
+          'getBranchData',
+          {
+            projectId: rootState.currentProjectId,
+            branchId: getters.branchName,
+          },
+          { root: true },
+        ).catch(() => {});
+      }
+
       dispatch('setLastCommitMessage', data);
       dispatch('updateCommitMessage', '');
       return dispatch('updateFilesAfterCommit', {
diff --git a/app/assets/javascripts/ide/stores/mutations/branch.js b/app/assets/javascripts/ide/stores/mutations/branch.js
index e09f88878f4..9e64b543748 100644
--- a/app/assets/javascripts/ide/stores/mutations/branch.js
+++ b/app/assets/javascripts/ide/stores/mutations/branch.js
@@ -19,6 +19,11 @@ export default {
     });
   },
   [types.SET_BRANCH_WORKING_REFERENCE](state, { projectId, branchId, reference }) {
+    if (!state.projects[projectId].branches[branchId]) {
+      Object.assign(state.projects[projectId].branches, {
+        [branchId]: {},
+      });
+    }
     Object.assign(state.projects[projectId].branches[branchId], {
       workingReference: reference,
     });
diff --git a/locale/gitlab.pot b/locale/gitlab.pot
index 350e06b2970..46fa17a6251 100644
--- a/locale/gitlab.pot
+++ b/locale/gitlab.pot
@@ -2597,6 +2597,9 @@ msgstr ""
 msgid "Create a new branch"
 msgstr ""
 
+msgid "Create a new file as there are no files yet. Afterwards, you'll be able to commit your changes."
+msgstr ""
+
 msgid "Create a new issue"
 msgstr ""
 
@@ -7349,6 +7352,9 @@ msgstr ""
 msgid "Select Archive Format"
 msgstr ""
 
+msgid "Select a file from the left sidebar to begin editing. Afterwards, you'll be able to commit your changes."
+msgstr ""
+
 msgid "Select a group to invite"
 msgstr ""
 
@@ -9454,6 +9460,9 @@ msgstr ""
 msgid "Webhooks Help"
 msgstr ""
 
+msgid "Welcome to the GitLab IDE"
+msgstr ""
+
 msgid "When a runner is locked, it cannot be assigned to other projects"
 msgstr ""
 
diff --git a/spec/frontend/ide/stores/mutations/branch_spec.js b/spec/frontend/ide/stores/mutations/branch_spec.js
index 29eb859ddaf..0900b25d5d3 100644
--- a/spec/frontend/ide/stores/mutations/branch_spec.js
+++ b/spec/frontend/ide/stores/mutations/branch_spec.js
@@ -37,4 +37,39 @@ describe('Multi-file store branch mutations', () => {
       expect(localState.projects.Example.branches.master.commit.title).toBe('Example commit');
     });
   });
+
+  describe('SET_BRANCH_WORKING_REFERENCE', () => {
+    beforeEach(() => {
+      localState.projects = {
+        Foo: {
+          branches: {
+            bar: {},
+          },
+        },
+      };
+    });
+
+    it('sets workingReference for existing branch', () => {
+      mutations.SET_BRANCH_WORKING_REFERENCE(localState, {
+        projectId: 'Foo',
+        branchId: 'bar',
+        reference: 'foo-bar-ref',
+      });
+
+      expect(localState.projects.Foo.branches.bar.workingReference).toBe('foo-bar-ref');
+    });
+
+    it('does not fail on non-existent just yet branch', () => {
+      expect(localState.projects.Foo.branches.unknown).toBeUndefined();
+
+      mutations.SET_BRANCH_WORKING_REFERENCE(localState, {
+        projectId: 'Foo',
+        branchId: 'unknown',
+        reference: 'fun-fun-ref',
+      });
+
+      expect(localState.projects.Foo.branches.unknown).not.toBeUndefined();
+      expect(localState.projects.Foo.branches.unknown.workingReference).toBe('fun-fun-ref');
+    });
+  });
 });
diff --git a/spec/javascripts/ide/stores/actions/project_spec.js b/spec/javascripts/ide/stores/actions/project_spec.js
index bf2a48ea3a9..0eda26546d6 100644
--- a/spec/javascripts/ide/stores/actions/project_spec.js
+++ b/spec/javascripts/ide/stores/actions/project_spec.js
@@ -4,7 +4,6 @@ import {
   refreshLastCommitData,
   showBranchNotFoundError,
   createNewBranchFromDefault,
-  getBranchData,
   showEmptyState,
   openBranch,
 } from '~/ide/stores/actions';
@@ -197,58 +196,6 @@ describe('IDE store project actions', () => {
     });
   });
 
-  describe('getBranchData', () => {
-    describe('error', () => {
-      let dispatch;
-      const callParams = [
-        {
-          commit() {},
-          dispatch,
-          state: store.state,
-        },
-        {
-          projectId: 'abc/def',
-          branchId: 'master-testing',
-        },
-      ];
-
-      beforeEach(() => {
-        dispatch = jasmine.createSpy('dispatchSpy');
-        document.body.innerHTML += '<div class="flash-container"></div>';
-      });
-
-      afterEach(() => {
-        document.querySelector('.flash-container').remove();
-      });
-
-      it('passes the error further unchanged without dispatching any action when response is 404', done => {
-        mock.onGet(/(.*)/).replyOnce(404);
-
-        getBranchData(...callParams)
-          .then(done.fail)
-          .catch(e => {
-            expect(dispatch.calls.count()).toEqual(0);
-            expect(e.response.status).toEqual(404);
-            expect(document.querySelector('.flash-alert')).toBeNull();
-            done();
-          });
-      });
-
-      it('does not pass the error further and flashes an alert if error is not 404', done => {
-        mock.onGet(/(.*)/).replyOnce(418);
-
-        getBranchData(...callParams)
-          .then(done.fail)
-          .catch(e => {
-            expect(dispatch.calls.count()).toEqual(0);
-            expect(e.response).toBeUndefined();
-            expect(document.querySelector('.flash-alert')).not.toBeNull();
-            done();
-          });
-      });
-    });
-  });
-
   describe('showEmptyState', () => {
     it('does nothing if error is not 404', done => {
       testAction(
diff --git a/spec/javascripts/ide/stores/actions/tree_spec.js b/spec/javascripts/ide/stores/actions/tree_spec.js
index 5ed9b9003a7..674ecdc6764 100644
--- a/spec/javascripts/ide/stores/actions/tree_spec.js
+++ b/spec/javascripts/ide/stores/actions/tree_spec.js
@@ -93,38 +93,6 @@ describe('Multi-file store tree actions', () => {
     });
 
     describe('error', () => {
-      it('dispatches branch not found actions when response is 404', done => {
-        const dispatch = jasmine.createSpy('dispatchSpy');
-
-        store.state.projects = {
-          'abc/def': {
-            web_url: `${gl.TEST_HOST}/files`,
-          },
-        };
-
-        mock.onGet(/(.*)/).replyOnce(404);
-
-        getFiles(
-          {
-            commit() {},
-            dispatch,
-            state: store.state,
-          },
-          {
-            projectId: 'abc/def',
-            branchId: 'master-testing',
-          },
-        )
-          .then(done.fail)
-          .catch(() => {
-            expect(dispatch.calls.argsFor(0)).toEqual([
-              'showBranchNotFoundError',
-              'master-testing',
-            ]);
-            done();
-          });
-      });
-
       it('dispatches error action', done => {
         const dispatch = jasmine.createSpy('dispatchSpy');
 
diff --git a/spec/javascripts/ide/stores/actions_spec.js b/spec/javascripts/ide/stores/actions_spec.js
index 0b5587d02ae..04e236fb042 100644
--- a/spec/javascripts/ide/stores/actions_spec.js
+++ b/spec/javascripts/ide/stores/actions_spec.js
@@ -9,12 +9,15 @@ import actions, {
   setErrorMessage,
   deleteEntry,
   renameEntry,
+  getBranchData,
 } from '~/ide/stores/actions';
+import axios from '~/lib/utils/axios_utils';
 import store from '~/ide/stores';
 import * as types from '~/ide/stores/mutation_types';
 import router from '~/ide/ide_router';
 import { resetStore, file } from '../helpers';
 import testAction from '../../helpers/vuex_action_helper';
+import MockAdapter from 'axios-mock-adapter';
 
 describe('Multi-file store actions', () => {
   beforeEach(() => {
@@ -560,4 +563,65 @@ describe('Multi-file store actions', () => {
       );
     });
   });
+
+  describe('getBranchData', () => {
+    let mock;
+
+    beforeEach(() => {
+      mock = new MockAdapter(axios);
+    });
+
+    afterEach(() => {
+      mock.restore();
+    });
+
+    describe('error', () => {
+      let dispatch;
+      const callParams = [
+        {
+          commit() {},
+          state: store.state,
+        },
+        {
+          projectId: 'abc/def',
+          branchId: 'master-testing',
+        },
+      ];
+
+      beforeEach(() => {
+        dispatch = jasmine.createSpy('dispatchSpy');
+        document.body.innerHTML += '<div class="flash-container"></div>';
+      });
+
+      afterEach(() => {
+        document.querySelector('.flash-container').remove();
+      });
+
+      it('passes the error further unchanged without dispatching any action when response is 404', done => {
+        mock.onGet(/(.*)/).replyOnce(404);
+
+        getBranchData(...callParams)
+          .then(done.fail)
+          .catch(e => {
+            expect(dispatch.calls.count()).toEqual(0);
+            expect(e.response.status).toEqual(404);
+            expect(document.querySelector('.flash-alert')).toBeNull();
+            done();
+          });
+      });
+
+      it('does not pass the error further and flashes an alert if error is not 404', done => {
+        mock.onGet(/(.*)/).replyOnce(418);
+
+        getBranchData(...callParams)
+          .then(done.fail)
+          .catch(e => {
+            expect(dispatch.calls.count()).toEqual(0);
+            expect(e.response).toBeUndefined();
+            expect(document.querySelector('.flash-alert')).not.toBeNull();
+            done();
+          });
+      });
+    });
+  });
 });
diff --git a/spec/javascripts/ide/stores/modules/commit/actions_spec.js b/spec/javascripts/ide/stores/modules/commit/actions_spec.js
index abc97f3072c..9e19c3e8bbc 100644
--- a/spec/javascripts/ide/stores/modules/commit/actions_spec.js
+++ b/spec/javascripts/ide/stores/modules/commit/actions_spec.js
@@ -271,6 +271,7 @@ describe('IDE commit module actions', () => {
         short_id: '123',
         message: 'test message',
         committed_date: 'date',
+        parent_ids: '321',
         stats: {
           additions: '1',
           deletions: '2',
@@ -462,5 +463,55 @@ describe('IDE commit module actions', () => {
           .catch(done.fail);
       });
     });
+
+    describe('first commit on empty repo', () => {
+      const COMMIT_RESPONSE = {
+        id: '123456',
+        short_id: '123',
+        message: 'test message',
+        committed_date: 'date',
+        parent_ids: [],
+        stats: {
+          additions: '1',
+          deletions: '2',
+        },
+      };
+
+      it('fetches branch info after very first commit', done => {
+        spyOn(service, 'commit').and.returnValue(
+          Promise.resolve({
+            data: COMMIT_RESPONSE,
+          }),
+        );
+
+        spyOn(store, 'dispatch').and.callThrough();
+
+        store
+          .dispatch('commit/commitChanges')
+          .then(() => {
+            expect(store.dispatch.calls.argsFor(1)[0]).toEqual('getBranchData');
+            done();
+          })
+          .catch(done.fail);
+      });
+
+      it('does not fetch branch after commit to existing project', done => {
+        COMMIT_RESPONSE.parent_ids.push('1234');
+        spyOn(service, 'commit').and.returnValue(
+          Promise.resolve({
+            data: COMMIT_RESPONSE,
+          }),
+        );
+        spyOn(store, 'dispatch').and.callThrough();
+
+        store
+          .dispatch('commit/commitChanges')
+          .then(() => {
+            expect(store.dispatch.calls.argsFor(1)[0]).not.toEqual('getBranchData');
+            done();
+          })
+          .catch(done.fail);
+      });
+    });
   });
 });