Refactor template script (#121)

* initial refactor of create-template-assignment script

* handling various git and github states

* update cmdline args for mode

* removed debugging line

* update message for missing config

* debugging template update script

* updating tests for new scripts

Author: kcranston

abcclassroom/__main__.py

@@ -417,62 +417,58 @@ def author():
     )
 
 
-def assignment_template():
+def new_template():
     """
     Create a new assignment template repository: creates local directory,
-    copy / create required files, intialize as git repo, create remote repo
-    on GitHub, and push local repo to GitHub. Will open git editor to ask for
-    commit message.
+    copy / create required files, intialize as git repo, and (optionally) create remote repo
+    on GitHub and push local repo to GitHub. Will open git editor to ask for
+    commit message if custom message requested.
     """
-    parser = argparse.ArgumentParser(description=assignment_template.__doc__)
+    parser = argparse.ArgumentParser(description=new_template.__doc__)
     parser.add_argument(
         "assignment",
         help="Name of assignment. Must match name in nbgrader release directory",
     )
     parser.add_argument(
         "--custom-message",
         action="store_true",
-        help="Use a custom commit message for git. Will open the default git text editor for entry. If not set, will use message 'Initial commit'.",
+        help="Use a custom commit message for git. Will open the default git text editor for entry (if not set, uses default message 'Initial commit').",
     )
     parser.add_argument(
-        "--local-only",
+        "--github",
         action="store_true",
-        help="Create local template repository only; do not create GitHub repo or  push to GitHub (default: False)",
+        help="Also perform the GitHub operations (create remote repo on GitHub and push to remote (by default, only does local repository setup)",
     )
     parser.add_argument(
         "--mode",
         choices=["delete", "fail", "merge"],
         default="fail",
-        help="Action if template directory already exists. Choices are: delete = delete the directory and contents; fail = exit and let user delete or rename; merge = keep existing dir, overwrite existing files, add new files. Default is fail.",
+        help="Action if template directory already exists. Choices are: delete = delete contents before proceeding (except .git directory); merge = keep existing dir, overwrite existing files, add new files (Default = fail).",
     )
     args = parser.parse_args()
 
-    print("Loading configuration from config.yml")
-    config = cf.get_config()
-    template_dir = cf.get_config_option(config, "template_dir", True)
-    # organization = get_config_option(config,"organization",True)
-
-    # these are the steps to create the local git repository
-    assignment = args.assignment
-    template_repo_path = template.create_template_dir(
-        config, assignment, args.mode
+    template.new_update_template(args)
+
+
+def update_template():
+    """
+    Updates an existing assignment template repository: update / add new and  changed files, then push local changes to GitHub. Will open git editor to ask for
+    commit message.
+    """
+    parser = argparse.ArgumentParser(description=update_template.__doc__)
+    parser.add_argument(
+        "assignment",
+        help="Name of assignment. Must match name in nbgrader release directory",
     )
-    print("repo path: {}".format(template_repo_path))
-    template.copy_assignment_files(config, template_repo_path, assignment)
-    template.create_extra_files(config, template_repo_path, assignment)
-    github.init_and_commit(template_repo_path, args.custom_message)
-
-    # now do the github things, unless we've been asked to only do local things
-    if not args.local_only:
-        organization = cf.get_config_option(config, "organization", True)
-        # get the name of the repo (the final dir in the path)
-        repo_name = os.path.basename(template_repo_path)
-        print("Creating repo {}".format(repo_name))
-        # create the remote repo on github and push the local repo
-        # (will print error and return if repo already exists)
-        github.create_repo(
-            organization,
-            repo_name,
-            template_repo_path,
-            cf.get_github_auth()["token"],
-        )
+    parser.add_argument(
+        "--mode",
+        choices=["delete", "merge"],
+        default="merge",
+        help="What to do with existing contents of template directory. Choices are: delete = remove contents before proceeding (leaving .git directory); merge = overwrite existing files add new files (Default = merge).",
+    )
+    args = parser.parse_args()
+    # now set the additional args (so that it matches the keys in add_template and we can use the same implementation
+    # methods)
+    setattr(args, "github", True)
+    setattr(args, "custom_message", True)
+    template.new_update_template(args)

abcclassroom/config.py

@@ -64,10 +64,9 @@ def get_config():
         return config
     except FileNotFoundError as err:
         print(
-            "Oops! I can't seem to find a config.yml file in your course "
-            "directory. If you don't have a course directory and config file  "
-            "setup yet, create one using  abc-quickstart. You will need to edit"
-            "the file to ensure it contains the variables related to your course"
+            "Oops! I can't seem to find a config.yml file in this "
+            "directory. Are you in the top-level directory for the course? If you don't have a course directory and config file "
+            "setup yet, you can create one using abc-quickstart"
             ".\n"
         )
         sys.exit(1)

abcclassroom/github.py

@@ -28,15 +28,27 @@ def _call_git(*args, directory=None):
         )
     except subprocess.CalledProcessError as e:
         err = e.stderr.decode("utf-8")
-        if err:
-            msg = err.split(":")[1].strip()
-        else:
-            msg = e.stdout.decode("utf-8")
-        raise RuntimeError(msg) from e
+        if not err:
+            err = e.stdout.decode("utf-8")
+        raise RuntimeError(err) from e
 
     return ret
 
 
+def remote_repo_exists(org, repository, token=None):
+    """Check if the remote repository exists for the assignment.
+    """
+
+    try:
+        g = gh3.login(token=token)
+        g.repository(org, repository)
+
+    except Exception as e:
+        return False
+
+    return True
+
+
 def check_student_repo_exists(org, course, student, token=None):
     """Check if the student has a repository for the course.
 
@@ -132,10 +144,8 @@ def create_pr(org, repository, branch, message, token):
     repo.create_pull(title, "master", branch, msg)
 
 
-def create_repo(org, repository, directory, token):
-    """Create a repository in the provided GitHub organization, adds that
-    repo as a remote to the local repo in directory, and pushes the
-    directory.
+def create_repo(org, repository, token):
+    """Create a repository in the provided GitHub organization.
     """
     github_obj = gh3.login(token=token)
     organization = github_obj.organization(org)
@@ -152,17 +162,13 @@ def create_repo(org, repository, directory, token):
                 org, repository
             )
         )
-        print("Not adding remote to local repo or pushing to github.")
-        return
-
-    _call_git(
-        "remote",
-        "add",
-        "origin",
-        "https://{}@github.com/{}/{}".format(token, org, repository),
-        directory=directory,
+
+
+def add_remote(directory, organization, remote_repo, token):
+    remote_url = "https://{}@github.com/{}/{}".format(
+        token, organization, remote_repo
     )
-    push_to_github(directory, "master")
+    _call_git("remote", "add", "origin", remote_url, directory=directory)
 
 
 def repo_changed(directory):
@@ -223,11 +229,18 @@ def init_and_commit(directory, custom_message=False):
                 print("Empty commit message, exiting.")
                 sys.exit(1)
         commit_all_changes(directory, message)
+    else:
+        print("No changes to local repository.")
 
 
 def push_to_github(directory, branch):
     """Push `branch` back to GitHub"""
-    _call_git("push", "--set-upstream", "origin", branch, directory=directory)
+    try:
+        _call_git(
+            "push", "--set-upstream", "origin", branch, directory=directory
+        )
+    except RuntimeError as e:
+        raise e
 
 
 def git_init(directory):

abcclassroom/template.py

@@ -6,22 +6,76 @@
 import os
 import sys
 import shutil
+from pathlib import Path
 
 from . import config as cf
 from . import github
 from . import utils
 
 
+def new_update_template(args):
+    """
+    Creates or updates an assignment template repository. Implementation of both the new_template and update_template console scripts (which perform the same basic functions but with different command line arguments and defaults).
+    """
+    print("Loading configuration from config.yml")
+    config = cf.get_config()
+    template_dir = cf.get_config_option(config, "template_dir", True)
+
+    # create the local git repository
+    assignment = args.assignment
+    template_repo_path = create_template_dir(config, assignment, args.mode)
+    print("repo path: {}".format(template_repo_path))
+    copy_assignment_files(config, template_repo_path, assignment)
+    create_extra_files(config, template_repo_path, assignment)
+    github.init_and_commit(template_repo_path, args.custom_message)
+
+    # optional github steps
+    if args.github:
+        organization = cf.get_config_option(config, "organization", True)
+        repo_name = os.path.basename(template_repo_path)
+        token = cf.get_github_auth()["token"]
+
+        create_or_update_remote(
+            template_repo_path, organization, repo_name, token
+        )
+
+
+def create_or_update_remote(
+    template_repo_path, organization, repo_name, token
+):
+    remote_exists = github.remote_repo_exists(organization, repo_name, token)
+    if not remote_exists:
+        print("Creating remote repo {}".format(repo_name))
+        # create the remote repo on github and push the local repo
+        # (will print error and return if repo already exists)
+        github.create_repo(organization, repo_name, token)
+
+    try:
+        github.add_remote(template_repo_path, organization, repo_name, token)
+    except RuntimeError as e:
+        print("Remote already added to local repository")
+        pass
+
+    print("Pushing any changes to remote repository on GitHub")
+    try:
+        github.push_to_github(template_repo_path, "master")
+    except RuntimeError as e:
+        print(
+            "Push to github failed. This is usually because there are changes on the remote that you do not have locally. Here is the github error:"
+        )
+        print(e)
+
+
 def create_template_dir(config, assignment, mode="fail"):
     """
     Creates a new directory in template_dir that will become the
-    template repository for the assignment.
+    template repository for the assignment. If directory exists and mode is  merge, do nothing. If directory exists and mode is delete, remove contents but leave .git directory.
     """
     course_dir = cf.get_config_option(config, "course_directory", True)
-    template_dir = cf.get_config_option(config, "template_dir", True)
-    parent_path = utils.get_abspath(template_dir, course_dir)
+    template_parent_dir = cf.get_config_option(config, "template_dir", True)
+    parent_path = utils.get_abspath(template_parent_dir, course_dir)
 
-    # check that course_dir/template_dir exists, and create it if it does not
+    # check that parent directory for templates exists, and create it if it does not
     if not os.path.isdir(parent_path):
         print(
             "Creating new directory for template repos at {}".format(
@@ -42,34 +96,45 @@ def create_template_dir(config, assignment, mode="fail"):
         sys.exit(1)
 
     repo_name = course_name + "-" + assignment + "-template"
-    template_path = os.path.join(parent_path, repo_name)
-    dir_exists = os.path.exists(template_path)
+    template_path = Path(parent_path, repo_name)
+    dir_exists = template_path.is_dir()
     if not dir_exists:
-        os.mkdir(template_path)
+        template_path.mkdir()
         print("Creating new template repo at {}".format(template_path))
     else:
         if mode == "fail":
             print(
-                "Directory {} already exists; re-run with '--mode merge' or --mode delete', or delete / move directory before re-running".format(
+                "Directory {} already exists; re-run with '--mode merge' or '--mode delete', or delete / move directory before re-running".format(
                     template_path
                 )
             )
             sys.exit(1)
         elif mode == "merge":
             print(
-                "Template directory {} already exists but mode is 'merge'; will keep directory but overwrite existing files with same names".format(
+                "Template directory {} already exists; will keep directory but overwrite existing files with same names".format(
                     template_path
                 )
             )
         else:
             # mode == delete
             print(
-                "Deleting existing directory and contents at {} and creating new empty directory with same name.".format(
+                "Template directory {} already exists; deleting existing files but keeping .git directory, if exists.".format(
                     template_path
                 )
             )
-            shutil.rmtree(template_path)
-            os.mkdir(template_path)
+            # temporarily move the .git dir to the parent of the template_path
+            gitdir = Path(template_path, ".git")
+            if gitdir.exists():
+                target = Path(Path(template_path).parent, ".tempgit")
+                gitdir.replace(target)
+
+                # remove template_path and re-create with same name
+                shutil.rmtree(template_path)
+                Path(template_path).mkdir()
+
+                # and then move the .git dir back
+                target.replace(gitdir)
+
     return template_path
 
 
@@ -96,6 +161,7 @@ def copy_assignment_files(config, template_repo, assignment):
     for file in all_files:
         fpath = os.path.join(release_dir, file)
         print("copying {} to {}".format(fpath, template_repo))
+        # overwrites if fpath exists in template_repo
         shutil.copy(fpath, template_repo)
         nfiles += 1
     print("Copied {} files".format(nfiles))