Merge pull request #541 from kgryte/cancel-merge

Add setting support for canceling a pull if merge conflict

Author: telamonian

README.md

@@ -2,7 +2,7 @@
 
 [![Binder](https://mybinder.org/badge_logo.svg)](https://mybinder.org/v2/gh/jupyterlab/jupyterlab-git/master?urlpath=lab/tree/examples/demo.ipynb) [![Build Status](https://travis-ci.org/jupyterlab/jupyterlab-git.svg?branch=master)](https://travis-ci.org/jupyterlab/jupyterlab-git) [![Version](https://img.shields.io/npm/v/@jupyterlab/git.svg)](https://www.npmjs.com/package/@jupyterlab/git) [![Version](https://img.shields.io/pypi/v/jupyterlab-git.svg)](https://pypi.org/project/jupyterlab-git/) [![Downloads](https://img.shields.io/npm/dm/@jupyterlab/git.svg)](https://www.npmjs.com/package/@jupyterlab/git) [![Version](https://img.shields.io/conda/vn/conda-forge/jupyterlab-git.svg)](https://anaconda.org/conda-forge/jupyterlab-git) [![Downloads](https://img.shields.io/conda/dn/conda-forge/jupyterlab-git.svg)](https://anaconda.org/conda-forge/jupyterlab-git)
 
-A JupyterLab extension for version control using git
+A JupyterLab extension for version control using Git
 
 ![](http://g.recordit.co/N9Ikzbyk8P.gif)
 
@@ -11,10 +11,11 @@ To see the extension in action, open the example notebook included in the Binder
 ## Prerequisites
 
 - JupyterLab
+- Git (version `>=1.7.4`)
 
 ## Usage
 
-- Open the git extension from the _Git_ tab on the left panel
+- Open the Git extension from the _Git_ tab on the left panel
 
 ## Install
 

jupyterlab_git/git.py

@@ -67,7 +67,6 @@ async def call_subprocess_with_authentication(
 
             returncode = p.wait()
             p.close()
-
             return returncode, "", response
         except pexpect.exceptions.EOF:  # In case of pexpect failure
             response = p.before
@@ -740,15 +739,15 @@ async def commit(self, commit_msg, top_repo_path):
             return {"code": code, "command": " ".join(cmd), "message": error}
         return {"code": code}
 
-    async def pull(self, curr_fb_path, auth=None):
+    async def pull(self, curr_fb_path, auth=None, cancel_on_conflict=False):
         """
         Execute git pull --no-commit.  Disables prompts for the password to avoid the terminal hanging while waiting
         for auth.
         """
         env = os.environ.copy()
         if auth:
             env["GIT_TERMINAL_PROMPT"] = "1"
-            code, _, error = await execute(
+            code, output, error = await execute(
                 ["git", "pull", "--no-commit"],
                 username=auth["username"],
                 password=auth["password"],
@@ -757,7 +756,7 @@ async def pull(self, curr_fb_path, auth=None):
             )
         else:
             env["GIT_TERMINAL_PROMPT"] = "0"
-            code, _, error = await execute(
+            code, output, error = await execute(
                 ["git", "pull", "--no-commit"],
                 env=env,
                 cwd=os.path.join(self.root_dir, curr_fb_path),
@@ -766,7 +765,21 @@ async def pull(self, curr_fb_path, auth=None):
         response = {"code": code}
 
         if code != 0:
-            response["message"] = error.strip()
+            output = output.strip()
+            has_conflict = "automatic merge failed; fix conflicts and then commit the result." in output.lower()
+            if cancel_on_conflict and has_conflict:
+                code, _, error = await execute(
+                    ["git", "merge", "--abort"],
+                    cwd=os.path.join(self.root_dir, curr_fb_path)
+                )
+                if code == 0:
+                    response["message"] = "Unable to pull latest changes as doing so would result in a merge conflict. In order to push your local changes, you may want to consider creating a new branch based on your current work and pushing the new branch. Provided your repository is hosted (e.g., on GitHub), once pushed, you can create a pull request against the original branch on the remote repository and manually resolve the conflicts during pull request review."
+                else:
+                    response["message"] = error.strip()
+            elif has_conflict:
+                response["message"] = output
+            else:
+                response["message"] = error.strip()
 
         return response
 

jupyterlab_git/handlers.py

@@ -416,7 +416,7 @@ async def post(self):
         POST request handler, pulls files from a remote branch to your current branch.
         """
         data = self.get_json_body()
-        response = await self.git.pull(data["current_path"], data.get("auth", None))
+        response = await self.git.pull(data["current_path"], data.get("auth", None), data.get("cancel_on_conflict", False))
 
         self.finish(json.dumps(response))
 

jupyterlab_git/tests/test_clone.py

@@ -154,4 +154,4 @@ async def test_git_clone_with_auth_auth_failure_from_git():
             assert {
                 "code": 128,
                 "message": "remote: Invalid username or password.\r\nfatal: Authentication failed for 'ghjkhjkl'",
-            } == actual_response
+            } == actual_response

jupyterlab_git/tests/test_pushpull.py

@@ -32,6 +32,27 @@ async def test_git_pull_fail():
             assert {"code": 1, "message": "Authentication failed"} == actual_response
 
 
+@pytest.mark.asyncio
+async def test_git_pull_with_conflict_fail():
+    with patch("os.environ", {"TEST": "test"}):
+        with patch("jupyterlab_git.git.execute") as mock_execute:
+            # Given
+            mock_execute.return_value = tornado.gen.maybe_future((1, "", "Automatic merge failed; fix conflicts and then commit the result."))
+
+            # When
+            actual_response = await Git(FakeContentManager("/bin")).pull("test_curr_path")
+
+            # Then
+            mock_execute.assert_has_calls([
+                call(
+                    ["git", "pull", "--no-commit"],
+                    cwd="/bin/test_curr_path",
+                    env={"TEST": "test", "GIT_TERMINAL_PROMPT": "0"},
+                )
+            ]);
+            assert {"code": 1, "message": "Automatic merge failed; fix conflicts and then commit the result."} == actual_response
+
+
 @pytest.mark.asyncio
 async def test_git_pull_with_auth_fail():
     with patch("os.environ", {"TEST": "test"}):
@@ -115,8 +136,34 @@ async def test_git_pull_with_auth_success():
 
 
 @pytest.mark.asyncio
-async def test_git_push_fail():
+async def test_git_pull_with_auth_success_and_conflict_fail():
+    with patch("os.environ", {"TEST": "test"}):
+        with patch("jupyterlab_git.git.execute") as mock_execute_with_authentication:
+            # Given
+            mock_execute_with_authentication.return_value = tornado.gen.maybe_future((1, "output", "Automatic merge failed; fix conflicts and then commit the result."))
+
+            # When
+            auth = {
+                "username" : "asdf", 
+                "password" : "qwerty"
+            }
+            actual_response = await Git(FakeContentManager("/bin")).pull("test_curr_path", auth)
+
+            # Then
+            mock_execute_with_authentication.assert_has_calls([
+                call(
+                    ["git", "pull", "--no-commit"],
+                    cwd="/bin/test_curr_path",
+                    env={"TEST": "test", "GIT_TERMINAL_PROMPT": "1"},
+                    username="asdf",
+                    password="qwerty"
+                )
+            ])
+            assert {"code": 1, "message": "Automatic merge failed; fix conflicts and then commit the result."} == actual_response
+
 
+@pytest.mark.asyncio
+async def test_git_push_fail():
     with patch("os.environ", {"TEST": "test"}):
         with patch("jupyterlab_git.git.execute") as mock_execute:
             # Given
@@ -221,4 +268,3 @@ async def test_git_push_with_auth_success():
                 env={"TEST": "test", "GIT_TERMINAL_PROMPT": "1"},
             )
             assert {"code": 0} == actual_response
-

schema/plugin.json

@@ -5,6 +5,12 @@
   "description": "jupyterlab-git settings.",
   "type": "object",
   "properties": {
+    "cancelPullMergeConflict": {
+      "type": "boolean",
+      "title": "Cancel pull merge conflict",
+      "description": "If true, when fetching and integrating changes from a remote repository, a conflicting merge is canceled and the working tree left untouched.",
+      "default": false
+    },
     "disableBranchWithChanges": {
       "type": "boolean",
       "title": "Disable branch with changes",

src/model.ts

@@ -24,6 +24,7 @@ export class GitExtension implements IGitExtension {
   ) {
     const model = this;
     this._app = app;
+    this._settings = settings || null;
 
     // Load the server root path
     this._getServerRoot()
@@ -742,7 +743,10 @@ export class GitExtension implements IGitExtension {
     try {
       let obj: Git.IPushPull = {
         current_path: path,
-        auth
+        auth,
+        cancel_on_conflict: this._settings
+          ? (this._settings.composite['cancelPullMergeConflict'] as boolean)
+          : false
       };
 
       let response = await httpGitRequest('/git/pull', 'POST', obj);
@@ -1038,6 +1042,7 @@ export class GitExtension implements IGitExtension {
   private _readyPromise: Promise<void> = Promise.resolve();
   private _pendingReadyPromise = 0;
   private _poll: Poll;
+  private _settings: ISettingRegistry.ISettings | null;
   private _headChanged = new Signal<IGitExtension, void>(this);
   private _markChanged = new Signal<IGitExtension, void>(this);
   private _repositoryChanged = new Signal<

src/tokens.ts

@@ -460,6 +460,7 @@ export namespace Git {
   export interface IPushPull {
     current_path: string;
     auth?: IAuth;
+    cancel_on_conflict?: boolean;
   }
 
   /**