Luc: undo changes

README.md

@@ -1,9 +1,17 @@
 # github-workshop
-Github flow workshop. [Slides](https://docs.google.com/presentation/d/14BZu5jpCzmWOHfjViLCeycy6ugyDZV9bGC074TMu9Jo/edit?usp=sharing)
+
+Github flow workshops 
+
+[Slides from Meili](https://docs.google.com/presentation/d/14BZu5jpCzmWOHfjViLCeycy6ugyDZV9bGC074TMu9Jo/edit?usp=sharing)
+
+[Slides from Denise](https://docs.google.com/presentation/d/18bI6VhPjsbpbTy51Ba7jh3lmS09zsnfMF778IiKDwYM/edit?usp=sharing)
 
 ## Install git
 
-If you don't have git on your machine, [install it]( https://help.github.com/articles/set-up-git/).
+If you don't have a GitHub account yet, [sign up](https://github.com/join)
+
+If you don't have git on your machine, [install and configure it]( https://help.github.com/articles/set-up-git/)
+
 
 ## Become a collaborator in this repository
 Come over to me to add you as a collaborator of this repository.
@@ -18,9 +26,9 @@ Now clone the repository to your machine. Go to your GitHub account, open the re
 Open a terminal and run the following git command:
 
 ```
-git clone "url you just copied"
+git clone <url you just copied>
 ```
-where "url you just copied" (without the quote marks) is the url to this repository (your fork of this project). See the previous steps to obtain the url.
+where "url you just copied" (without the < > signs) is the url to this repository. See the previous steps to obtain the url.
 
 <img align="right" width="300" src="assets/copy-to-clipboard.png" alt="copy URL to clipboard" />
 
@@ -35,7 +43,7 @@ Now create a branch using the `git checkout` command:
 ```
 git checkout -b <add-your-new-branch-name>
 ```
-The branch will be to edit the file `commit-messages.md` in this repository and add your tips. So name it something relevant, including your name so that it is not the same with the rest of the people.
+On your branch (local copy of the repository) you will edit the file `commit-messages.md` in this repository and add some tips on how to write good commit messages. Give your branch a meaningful name, including your name so that it is not the same as the branch of everyone else in the workshop.
 
 For example:
 ```
@@ -45,6 +53,7 @@ git checkout -b add-george-tips
 ### Make necessary changes and commit those changes
 
 Now open `commit-messages.md` file in a text editor, and add your tips for writing good commit messages. 
+Save the changed markdown file.
 
 
 If you go to the project directory and execute the command `git status`, you'll see there are changes.
@@ -56,12 +65,17 @@ Add those changes to the branch you just created using the `git add` command:
 git add commit-messages.md
 ```
 
+Hit `git status` again to see how the changes are still there but now they are staged for commit (it's a necessary preparation)
+
 Now commit those changes with a nice commit message using the `git commit` command:
 ```
 git commit -m "Add HERE your commit message"
 ```
 replacing the text in `""` with your commit message.
 
+Up until now, you have not submitted anything to GitHub!
+
+
 ### Push changes to GitHub
 
 Push your changes using the command `git push`:
@@ -70,89 +84,148 @@ git push origin <add-your-branch-name>
 ```
 replacing `<add-your-branch-name>` with the name of the branch you created earlier.
 
+<img align="right" width="300" src="assets/change_base_repo.png" alt="change base repo" />
+
 ### Submit your changes for review
 
-If you go to your repository on GitHub, you'll see a  `Compare & pull request` button (in Gitlab it is called `Merge request`)
-Click on that button.
+Now go to your repository on GitHub, you'll see a  `Compare & pull request` button. Click on that button.
+
+Before sumitting the Pull Request, make sure to change the base repository from mei-li/github-workshop to the current fork of the repo denisesenguel/github-workshop.
+Afterwards it should be `master` at the left and your branch at the right. It should look something like this
 
-It should be `master` at the left and your branch at the right. Sth like
-`master <- your-branch-name`
+<img align="center" width="900" src="assets/merge_settings_pr.png" alt="merge settings pr" />
 
+You may change the title of the Pull request if you want to. It should be short but informative about all the changes you did.
 Now submit the pull request.
 
 ### Get a review
-Now exchange reviewes with a person sitting near you. In github you can assign them as a reviewer in your Pull Request or tell them your Pull request number.
+
+Now exchange reviewes with a person sitting near you. In GitHub you can assign them as a reviewer in your Pull Request or tell/send them your Pull request number.
 
 ### Submit a review
-Github offers 2 ways of reviewing, either with `single comments` or with `start review` that let you add multiple comments that will be visible when selecting the `submit review`. This way they will show all together. Use the `signle comments`
+Github offers 2 ways of reviewing, either with `single comments` or with `start review` that let you add multiple comments that will be visible when selecting the `submit review`. This way they will show all together. Use the `single comments`
 
 Add a review and ask the author to make some change. A review should be respectful and explain the reason that the change is needed, giving context. 
 
 ### Address comments
 
-Address the comments of the review or reply to them explaining your reasoning. If see that the suggested changes make sense, make the changes locally and push the updates. Use a meaningful commit message when addressing the comments eg. `Improve wording` instead of `addressing comments`
+Address the comments of the review or reply to them explaining your reasoning. If see that the suggested changes make sense, make the changes locally and save. Then add, commit and push the updates to GitHub as you did with the initial changes.
+
+Use a meaningful commit message when addressing the comments eg. `Improve wording` instead of `addressing comments`
 
 ### Where to go from here?
 
 Congrats!  You just completed the standard clone -> edit -> PR_ workflow that helps you collaborate and share knowledge with your team!
 
-## Part II - Rewrite history
 
-Rewritting history in git is possible. One should be careful not to do that, in any branch that is already shared with somebody else. To be on the safe side do history rewrites before pushing the commits or in another branch.
+## Part II - Undoing changes
+
+If you realize that you want to undo some changes you've made, you have several options and it depends on what you have done before.
+Rewritting history in git is possible. One should be careful not to do that, in general because changes might get lost and in particular on any branch that is already shared with somebody else. 
+To be on the safe side do history rewrites **before** pushing the commits or even better in an additional branch!
 
+### Your options
 
-### Get the ugly-history
+- If you have not added (we call it "staged") or commited a change yet `git checkout <filename>` removes all of the local changes on the file.  Be careful with this one, you might easily lose relevant work
+- If you have already added but not yet commited a change `git reset HEAD <filename>`
 
-Start a branch from the `ugly-history` branch
+For changes that have already been commited:
+
+- `git commit --amend -m "your new commit message"` lets you add some changes to your previous commit (use on private branches only)
+- `git revert <commitID>` lets you undo a specific commit as an additional commit. This is a very safe option also if you shared a branch already
+- `git reset --soft <commitID>` there is also a `--hard` flag but don't use it unless you know exactly what you are doing!
+
+
+### Rewriting history
+
+Get the ugly-history branch and start a new branch from it
 
-Tip
 ```
-git checkout <BRANCH_TO_BASE_YOURS>
-git checkout -b <NEW_BRANCH>
+git checkout <ugly-history>
+git checkout -b <your_new_branch>
 ``` 
 
-## Look at the commits
+### Look at the commits
+
+Use git log to look at the commit history (last 10 commits)
+
+```
+git log -10
+```
 
-Use git log to look at the commit messages
+### Undo a commit
 
+Revert the commit where `commit-message.md` is added by running
 ```
-git log -5
+git revert --no-edit <commit hash> 
 ```
+and again check your commit history. The commit ID can be obtained from the commit history.
+
 
-Optional things
+### Rewrite the last 4 commits
 
-Tip:
-to make your git log look more compact like this:
+Now undo the last 5 commits and split them into two, one adding the `hello.py` file and one the `goodbye.py`
+Use
+```
+git reset --soft HEAD~5
+```
+Then add and commit as described.
+
+
+### Before pushing
+
+Imagine that you forgot to add some comment. Add a random comment to `hello.py`or `goodbye.py` and amend the last commit.
+
+
+### Push and make a Pull request
+
+Push your new branch and make a Pull request. Ask for your reviewer to check the commits. 
+
+
+## Part III (Optional): Playing around some more 
+
+### .gitignore
+
+As the name suggests `.gitignore` is a list of files to be ignored by git. That means that changes in these files will not be tracked and thus also not end up on GitHub or any other hosting service. (example: sensitive data)
+
+Add a new empty file of any type to your repository.
+Open the hidden file `.gitignore` via your Terminal in a text editor.
+Add the new file you just created **and** another previously existing file in your repository to the file list.
+Add and commit your changes and watch what happens to understand `.gitignore` better.
+
+### Merge Conflicts
+
+Team up with your collaborators. Merge one of your reviewed pull requests and then see what happens with your open pull requests!
+
+
+## Some more Tips
+
+If a command like add, commit or reset applies to all of your changed files (not just one) use for example `git add .` or `git add *` to not run the command on every single file separately.
+
+### Prettify
+
+To make your git log look more compact like this:
 ```
 16fed12 [4 minutes ago] (Meili Triantafyllidi) improve commit message tip
 5a964a3 [13 minutes ago] (Meili Triantafyllidi) add slides and start part II
 13ddeff [14 minutes ago] (Meili Triantafyllidi) add assets
 707334e [4 hours ago] (Meili Triantafyllidi) add github workflow part I
 ```
-you can edit you ``.gitconfig` file which is in you home directory and add this in the format section. Like this:
+
+you can edit your `.gitconfig` file which is in you home directory and add this in the format section. Like this:
 
 ```
 [format]
   pretty = %C(magenta reverse)%h%Creset %Cgreen[%cr]%Creset (%an) %s
 
 ```
 
-## Rewrite the last 4 commits
+## Additional material 
 
-Undo the last 4 commits and split them into two, one adding the `hello.py` file and one the `goodbye.py`
+More to be added.
 
-## Before pushing
-
-Imagine that you forgot to add some comment. Add that comment in the code and amend the last commit.
-
-## Push and make a Pull request
-
-push your new branch and make a Pull request. Ask for your reviewer to check the commits. 
-
-## Congratulations
-Check how the gitlab workshop is below
+Gitlab workshop:
+[Gitlab workflow](https://about.gitlab.com/blog/2017/03/17/demo-mastering-code-review-with-gitlab/)
 
 
-### [Additional material]
-[Gitlab workflow](https://about.gitlab.com/blog/2017/03/17/demo-mastering-code-review-with-gitlab/)
 

good-commit-message.md

@@ -3,14 +3,3 @@
 add your tip
 
 - Start a commit message with a verb eg. `add`, `change` etc
-
-funny branch tips 
---------
-- **first tip**
-```
-git checkout -b <add-your-new-branch-name>
-```
-- **second tip**
-```
-git log -5
-```

hello.py

@@ -0,0 +1 @@
+#  print hello to the user