Set tree list accounting for already-opened files57668-create-file-from-url

Since we can create files from URL now, this means that these files will
not exist in the tree returned from API: they exist on the client
only before the first commit. In order to still show the newly-created
files in the tree, we should not override the tree, but merge the tree
existing on the client and the one coming from API.

Changelog entry

Moved trees merging into mutation

6 files changed, 249 insertions, 17 deletions

diff --git a/app/assets/javascripts/ide/stores/mutations/tree.js b/app/assets/javascripts/ide/stores/mutations/tree.js
index eac7441ee54..359943b4ab7 100644
--- a/app/assets/javascripts/ide/stores/mutations/tree.js
+++ b/app/assets/javascripts/ide/stores/mutations/tree.js
@@ -1,5 +1,5 @@
 import * as types from '../mutation_types';
-import { sortTree } from '../utils';
+import { sortTree, mergeTrees } from '../utils';
 
 export default {
   [types.TOGGLE_TREE_OPEN](state, path) {
@@ -23,9 +23,15 @@ export default {
     });
   },
   [types.SET_DIRECTORY_DATA](state, { data, treePath }) {
-    Object.assign(state.trees[treePath], {
-      tree: data,
-    });
+    const selectedTree = state.trees[treePath];
+
+    // If we opened files while loading the tree, we need to merge them
+    // Otherwise, simply overwrite the tree
+    const tree = !selectedTree.tree.length
+      ? data
+      : selectedTree.loading && mergeTrees(selectedTree.tree, data);
+
+    Object.assign(selectedTree, { tree });
   },
   [types.SET_LAST_COMMIT_URL](state, { tree = state, url }) {
     Object.assign(tree, {
diff --git a/app/assets/javascripts/ide/stores/utils.js b/app/assets/javascripts/ide/stores/utils.js
index 0b2a18e9c8a..3ab8f3f11be 100644
--- a/app/assets/javascripts/ide/stores/utils.js
+++ b/app/assets/javascripts/ide/stores/utils.js
@@ -170,3 +170,31 @@ export const filePathMatches = (filePath, path) => filePath.indexOf(`${path}/`)
 
 export const getChangesCountForFiles = (files, path) =>
   files.filter(f => filePathMatches(f.path, path)).length;
+
+export const mergeTrees = (fromTree, toTree) => {
+  if (!fromTree || !fromTree.length) {
+    return toTree;
+  }
+
+  const recurseTree = (n, t) => {
+    if (!n) {
+      return t;
+    }
+    const existingTreeNode = t.find(el => el.path === n.path);
+
+    if (existingTreeNode && n.tree.length > 0) {
+      existingTreeNode.opened = true;
+      recurseTree(n.tree[0], existingTreeNode.tree);
+    } else if (!existingTreeNode) {
+      const sorted = sortTree(t.concat(n));
+      t.splice(0, t.length + 1, ...sorted);
+    }
+    return t;
+  };
+
+  for (let i = 0, l = fromTree.length; i < l; i += 1) {
+    recurseTree(fromTree[i], toTree);
+  }
+
+  return toTree;
+};
diff --git a/changelogs/unreleased/57668-create-file-from-url.yml b/changelogs/unreleased/57668-create-file-from-url.yml
new file mode 100644
index 00000000000..b6033fa24ca
--- /dev/null
+++ b/changelogs/unreleased/57668-create-file-from-url.yml
@@ -0,0 +1,5 @@
+---
+title: Implemented support for creation of new files from URL in Web IDE
+merge_request: 26622
+author:
+type: added
diff --git a/spec/javascripts/ide/stores/actions/tree_spec.js b/spec/javascripts/ide/stores/actions/tree_spec.js
index fbb676aab33..5ed9b9003a7 100644
--- a/spec/javascripts/ide/stores/actions/tree_spec.js
+++ b/spec/javascripts/ide/stores/actions/tree_spec.js
@@ -1,6 +1,6 @@
 import MockAdapter from 'axios-mock-adapter';
 import testAction from 'spec/helpers/vuex_action_helper';
-import { showTreeEntry, getFiles } from '~/ide/stores/actions/tree';
+import { showTreeEntry, getFiles, setDirectoryData } from '~/ide/stores/actions/tree';
 import * as types from '~/ide/stores/mutation_types';
 import axios from '~/lib/utils/axios_utils';
 import store from '~/ide/stores';
@@ -206,4 +206,35 @@ describe('Multi-file store tree actions', () => {
       );
     });
   });
+
+  describe('setDirectoryData', () => {
+    it('sets tree correctly if there are no opened files yet', done => {
+      const treeFile = file({ name: 'README.md' });
+      store.state.trees['abcproject/master'] = {};
+
+      testAction(
+        setDirectoryData,
+        { projectId: 'abcproject', branchId: 'master', treeList: [treeFile] },
+        store.state,
+        [
+          {
+            type: types.SET_DIRECTORY_DATA,
+            payload: {
+              treePath: 'abcproject/master',
+              data: [treeFile],
+            },
+          },
+          {
+            type: types.TOGGLE_LOADING,
+            payload: {
+              entry: {},
+              forceValue: false,
+            },
+          },
+        ],
+        [],
+        done,
+      );
+    });
+  });
 });
diff --git a/spec/javascripts/ide/stores/mutations/tree_spec.js b/spec/javascripts/ide/stores/mutations/tree_spec.js
index 67e9f7509da..7f9c978aa46 100644
--- a/spec/javascripts/ide/stores/mutations/tree_spec.js
+++ b/spec/javascripts/ide/stores/mutations/tree_spec.js
@@ -26,17 +26,11 @@ describe('Multi-file store tree mutations', () => {
   });
 
   describe('SET_DIRECTORY_DATA', () => {
-    const data = [
-      {
-        name: 'tree',
-      },
-      {
-        name: 'submodule',
-      },
-      {
-        name: 'blob',
-      },
-    ];
+    let data;
+
+    beforeEach(() => {
+      data = [file('tree'), file('foo'), file('blob')];
+    });
 
     it('adds directory data', () => {
       localState.trees['project/master'] = {
@@ -52,7 +46,7 @@ describe('Multi-file store tree mutations', () => {
 
       expect(tree.tree.length).toBe(3);
       expect(tree.tree[0].name).toBe('tree');
-      expect(tree.tree[1].name).toBe('submodule');
+      expect(tree.tree[1].name).toBe('foo');
       expect(tree.tree[2].name).toBe('blob');
     });
 
@@ -65,6 +59,49 @@ describe('Multi-file store tree mutations', () => {
 
       expect(localState.trees['project/master'].loading).toBe(true);
     });
+
+    it('does not override tree already in state, but merges the two with correct order', () => {
+      const openedFile = file('new');
+
+      localState.trees['project/master'] = {
+        loading: true,
+        tree: [openedFile],
+      };
+
+      mutations.SET_DIRECTORY_DATA(localState, {
+        data,
+        treePath: 'project/master',
+      });
+
+      const { tree } = localState.trees['project/master'];
+
+      expect(tree.length).toBe(4);
+      expect(tree[0].name).toBe('blob');
+      expect(tree[1].name).toBe('foo');
+      expect(tree[2].name).toBe('new');
+      expect(tree[3].name).toBe('tree');
+    });
+
+    it('returns tree unchanged if the opened file is already in the tree', () => {
+      const openedFile = file('foo');
+      localState.trees['project/master'] = {
+        loading: true,
+        tree: [openedFile],
+      };
+
+      mutations.SET_DIRECTORY_DATA(localState, {
+        data,
+        treePath: 'project/master',
+      });
+
+      const { tree } = localState.trees['project/master'];
+
+      expect(tree.length).toBe(3);
+
+      expect(tree[0].name).toBe('tree');
+      expect(tree[1].name).toBe('foo');
+      expect(tree[2].name).toBe('blob');
+    });
   });
 
   describe('REMOVE_ALL_CHANGES_FILES', () => {
diff --git a/spec/javascripts/ide/stores/utils_spec.js b/spec/javascripts/ide/stores/utils_spec.js
index 9f18034f8a3..c4f122efdda 100644
--- a/spec/javascripts/ide/stores/utils_spec.js
+++ b/spec/javascripts/ide/stores/utils_spec.js
@@ -235,4 +235,129 @@ describe('Multi-file store utils', () => {
       ]);
     });
   });
+
+  describe('mergeTrees', () => {
+    let fromTree;
+    let toTree;
+
+    beforeEach(() => {
+      fromTree = [file('foo')];
+      toTree = [file('bar')];
+    });
+
+    it('merges simple trees with sorting the result', () => {
+      toTree = [file('beta'), file('alpha'), file('gamma')];
+      const res = utils.mergeTrees(fromTree, toTree);
+
+      expect(res.length).toEqual(4);
+      expect(res[0].name).toEqual('alpha');
+      expect(res[1].name).toEqual('beta');
+      expect(res[2].name).toEqual('foo');
+      expect(res[3].name).toEqual('gamma');
+      expect(res[2]).toBe(fromTree[0]);
+    });
+
+    it('handles edge cases', () => {
+      expect(utils.mergeTrees({}, []).length).toEqual(0);
+
+      let res = utils.mergeTrees({}, toTree);
+
+      expect(res.length).toEqual(1);
+      expect(res[0].name).toEqual('bar');
+
+      res = utils.mergeTrees(fromTree, []);
+
+      expect(res.length).toEqual(1);
+      expect(res[0].name).toEqual('foo');
+      expect(res[0]).toBe(fromTree[0]);
+    });
+
+    it('merges simple trees without producing duplicates', () => {
+      toTree.push(file('foo'));
+
+      const res = utils.mergeTrees(fromTree, toTree);
+
+      expect(res.length).toEqual(2);
+      expect(res[0].name).toEqual('bar');
+      expect(res[1].name).toEqual('foo');
+      expect(res[1]).not.toBe(fromTree[0]);
+    });
+
+    it('merges nested tree into the main one without duplicates', () => {
+      fromTree[0].tree.push({
+        ...file('alpha'),
+        path: 'foo/alpha',
+        tree: [
+          {
+            ...file('beta.md'),
+            path: 'foo/alpha/beta.md',
+          },
+        ],
+      });
+
+      toTree.push({
+        ...file('foo'),
+        tree: [
+          {
+            ...file('alpha'),
+            path: 'foo/alpha',
+            tree: [
+              {
+                ...file('gamma.md'),
+                path: 'foo/alpha/gamma.md',
+              },
+            ],
+          },
+        ],
+      });
+
+      const res = utils.mergeTrees(fromTree, toTree);
+
+      expect(res.length).toEqual(2);
+      expect(res[1].name).toEqual('foo');
+
+      const finalBranch = res[1].tree[0].tree;
+
+      expect(finalBranch.length).toEqual(2);
+      expect(finalBranch[0].name).toEqual('beta.md');
+      expect(finalBranch[1].name).toEqual('gamma.md');
+    });
+
+    it('marks correct folders as opened as the parsing goes on', () => {
+      fromTree[0].tree.push({
+        ...file('alpha'),
+        path: 'foo/alpha',
+        tree: [
+          {
+            ...file('beta.md'),
+            path: 'foo/alpha/beta.md',
+          },
+        ],
+      });
+
+      toTree.push({
+        ...file('foo'),
+        tree: [
+          {
+            ...file('alpha'),
+            path: 'foo/alpha',
+            tree: [
+              {
+                ...file('gamma.md'),
+                path: 'foo/alpha/gamma.md',
+              },
+            ],
+          },
+        ],
+      });
+
+      const res = utils.mergeTrees(fromTree, toTree);
+
+      expect(res[1].name).toEqual('foo');
+      expect(res[1].opened).toEqual(true);
+
+      expect(res[1].tree[0].name).toEqual('alpha');
+      expect(res[1].tree[0].opened).toEqual(true);
+    });
+  });
 });