Forge User and Developer Manual

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Forge User and Developer Manual

Forge allows you to work with Git forges, such as Github and Gitlab, from the comfort of Magit and the rest of Emacs.

This manual is for Forge version 0.1.0.

Copyright (C) 2018 Jonas Bernoulli <jonas@bernoul.li>

You can redistribute this document and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version.

This document is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.


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1 Introduction

Forge allows you to work with Git forges, such as Github and Gitlab, from the comfort of Magit and the rest of Emacs.

Forge fetches issues, pull-requests and other data using the forge’s API and stores that in a local database. Additionally it fetches the pull-request references using Git. Forge implements various features that use this data but the database and pull-request refs can also be used by third-party packages.


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2 Supported Forges and Hosts

Currently Forge supports two forges and three more forges partially. Additionally it supports four semi-forges. Support for more forges and semi-forges can and will be added.

Both forges and semi-forges provide web interfaces for Git repositories. Forges additionally support pull-requests and issues and make those and other information available using an API.

When a forge is only partially supported, then that means that only the functionality that does not require the API is implemented, or in other words, that the forge is only supported as a semi-forge.

A host is a particular instance of a forge. For example the hosts https://gitlab.com and https://salsa.debian.org are both instances of the Gitlab forge. Forge supports some well known hosts out of the box and additional hosts can easily be supported by adding entries to the option forge-alist.

For more details about the caveats mentioned below (and some others) also see Getting Started.

2.1 Supported Forges

2.2 Partially Supported Forges

2.3 Supported Semi-Forges


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3 Getting Started

Getting started using Forge should be fairly easy, but there are a few caveats you should be aware of:


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3.1 Initial Pull

To start using Forge in a certain repository visit the Magit status buffer for that repository and type F y (forge-pull).

The first time you do that for any repository from https://github.com you will be guided through the process of creating the API token. For other forges as well as for other Github instances some additional setup is required before you do so. See Token Creation.

The first time forge-pull is run in a repository, an entry for that repository is added to the database and a new value is added to the Git variable remote.<remote>.fetch, which fetches all pull-requests. (+refs/pull/*/head:refs/pullreqs/* for Github)

forge-pull then fetches topics and other information using the forge’s API and pull-request references using Git.

The initial fetch can take a while but most of that is done asynchronously. Storing the information in the database is done synchronously though, so there can be a noticeable hang at the end. Subsequent fetches are much faster.

Fetching issues from Github is much faster than fetching from other forges because making a handful of GraphQl requests is much faster than making hundreds of REST requests.


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3.2 Token Creation

Forge uses the Ghub package to access the APIs of supported Git forges. Ghub comes with a setup wizard that guides the user through the process of creating an API token for Github.com. When accessing a Github Enterprise instance, then some manual setup is required before the wizard can be used. Other forges don’t support creating tokens using the API at all. Before accessing such a forge you have to create a token using the respective web interface.

Please consult Ghub’s manual to learn more about token creation. See (ghub)Getting Started in particular.

Ghub does not associate a given local repository with a repository on a forge. The Forge package itself takes care of this. In doing so it ignores the Git variable ghub.host and other FORGE.host variables used by Ghub. (But github.user and other variables used to specify the user are honored). Forge associates the local repository with a forge repository by first determining which remote is associated with the upstream repository and then looking that up in forge-alist.

If only one remote exists, then Forge uses that unconditionally. If several remotes exist, then a remote may be selected based on its name.

The convention is to name the upstream remote origin. If you follow this convention, then you have to do nothing else and the remote by that name is automatically used, provided it exists and regardless of whether other remotes exist. If it does not exist, then no other remotes are tried.

If you do not follow the naming convention, then you have to inform Forge about that by setting the Git variable forge.remote to the name that you instead use for upstream remotes. If this variable is set, then Forge uses the remote by that name, if it exists, the same way it may have used origin if the the variable were undefined. I.e. it does not fall through to try origin if no remote by your chosen name exists.

Once the upstream remote has been determined, Forge looks it up in forge-alist, using the host part of the url as the key. For example the key for git@github.com:magit/forge.git is github.com.


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4 Usage

Once information has been fetched from a repository’s forge, Forge adds two additional sections named "Pull requests" and "Issues" to Magit’s status buffer. Some of Forge’s commands are only bound when point is within one of these sections but other commands are also available elsewhere in Magit’s status buffer and/or from Magit’s popup commands.

'     (forge-dispatch-popup)

This prefix command is available in any Magit buffer and provides access to several of the available Forge commands. Most of these commands are also bound elsewhere, but some or not. See the following sections for information about the available commands.


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4.1 Pulling

The commands that pull forge data are available from the same popup (magit-pull-popup on F) that is used to pull Git data.

F y     (forge-pull)

This command uses a forge’s API to fetch topics and other information about the current repository and stores the fetched information in the database. It also fetches notifications for all repositories from the same forge host. (Currently this is limitted to Github.) Finally it fetches pull-request references using Git.

After using this command for the first time in a given repository the status buffer for that repository always lists the pull-requests and issues. See Initial Pull.

F Y     (forge-pull-notifications)

This command uses a forge’s API to fetch all notifications from that forge, including but not limited to the notifications for the current repository.

Fetching all notifications fetches associated topics even if you have not started fetching all topics for the respective repositories (using forge-pull), but it does not cause the topics to be listed in the status buffer of such "uninitialized" repositories.

Note how pulling data from a forge’s API works the same way as pulling Git data does; you do it explicitly when you want to see the work done by others.

This is less disruptive, more reliable and easier to understand than if Forge did the pulling by itself at random intervals. It might however mean that you occasionally invoke a command expecting the most recent data to be available and then having to abort to pull first. The same can happen with Git, e.g. you might attempt to merge a branch that you know exists but haven’t actually pulled yet.

M-x forge-pull-pullreq     (forge-pull-pullreq)

This command uses a forge’s API to fetch a single pull-request and stores it in the database.

Normally you wouldn’t want to pull a single pull-request by itself, but due to a bug in the Github API you might sometimes have to do so.

Fetching is implemented under the assumption that the API can be asked to list the things that have changed since we last checked. Unfortunately the APIs are not bug-free, so this is not always the case. Issues such as https://platform.github.community/t/7284 can take years to get addresses (in closed-source software), so I am no longer delaying the initial Forge release because of that. If in doubt, then re-fetch an individual pull-request to ensure it is up-to-date using this command.


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4.2 Branching

Forge provides commands for creating and checking out a new branch or worktree from a pull-request. These commands are available from the same popups as the commands used to create and check out branches and worktrees in a more generic fashion (magit-branch-popup on b and magit-worktree-popup on %).

b Y     (forge-branch-pullreq)

This command creates and configures a new branch from a pull-request, creating and configuring a new remote if necessary.

The name of the local branch is the same as the name of the remote branch that you are being asked to merge, unless the contributor could not be bother to properly name the branch before opening the pull-request. The most likely such case is when you are being asked to merge something like "fork/master" into "origin/master". In such cases the local branch will be named "pr-N", where N is the pull-request number.

These variables are always set by this command:

This command also configures the upstream and the push-remote of the local branch that it creates.

The branch against which the pull-request was opened, is always used as the upstream. This makes it easy to see what commits you are being asked to merge in the section titled something like "Unmerged into origin/master".

Like for other commands that create a branch it depends on the option magit-branch-prefer-remote-upstream whether the remote branch itself or the respective local branch is used as the upstream, so this section may also be titled e.g. "Unmerged into master".

When necessary and possible, then the remote pull-request branch is configured to be used as the push-target. This makes it easy to see what further changes the contributor has made since you last reviewed their changes in the section titled something like "Unpulled from origin/new-feature" or "Unpulled from fork/new-feature".

b y     (forge-checkout-pullreq)

This command creates and configures a new branch from a pull-request the same way forge-branch-pullreq does. Additionally it checks out the new branch.

% y     (forge-checkout-worktree)

This command creates and configures a new branch from a pull-request the same way forge-branch-pullreq does. Additionally it checks out the new branch using a new working tree.

When you delete a pull-request branch, which was created using one of the above three commands, then magit-branch-delete usually offers to also delete the corresponding remote. It does not offer to delete a remote if (1) the remote is the upstream remote, and/or (2) if other branches are being fetched from the remote.

Note that you have to delete the local branch (e.g. "feature") for this to work. If you delete the tracking branch (e.g "fork/feature"), then the remote is never removed.


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4.3 Working with Topics

We call both issues and pull-requests "topics". The contributions to the conversation are called "posts".


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4.3.1 Visiting Topics

Magit’s status buffer contains lists of issues and pull-requests. Topics are ordered by last modification time. All open issues and some recently edited and closed topics are listed.

Forge provides some commands that act on the listed topics. These commands can also be used in other contexts, such as when point is on a commit or branch section.

C-c C-w     (forge-browse-TYPE)
C-c C-w     (forge-browse-dwim)

These commands visit the pull-request(s), issue(s), post, branch, commit or remote at point in a browser.

This is implemented using various commands named forge-browse-TYPE, and the key binding is defined by remapping magit-browse-thing (as defined in magit-mode-map). For commit sections this key is bound to forge-browse-dwim, which prefers a topic over a branch and a branch over a commit.

RET     (forge-visit-TYPE)
C-c C-v     (forge-visit-topic)

These commands visit the pull-request or issue at point in a separate buffer.

The RET binding is only available when point is on a issue or pull-request section because that key is already bound to something else for most of Magit’s own sections. C-c C-v however is also available on regular commit (e.g. in a log) and branch sections.

This is implemented using various commands named forge-visit-TYPE and the key binding is defined by remapping magit-visit-thing (as defined in magit-mode-map).


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4.3.2 Listing Topics and Notifications

Magit’s status buffer contains lists of issues and pull-requests, but you can also list topics as well as notifications in separate buffers.

' l     (forge-list-notifications)

This command lists all notifications for all forges in a separate buffer.

' P     (forge-list-pull-requests)

This command lists the current repository’s pull-requests in a separate buffer.

' I     (forge-list-issues)

This command lists the current repository’s issues in a separate buffer.


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4.3.3 Creating Topics

' p     (forge-create-pullreq)
C-n C-n [on "Pull requests" section]     (forge-create-pullreq)

This command creates a new pull-request for the current repository.

' i     (forge-create-issue)
C-n C-n [on "Issues" section]     (forge-create-pullreq)

This command creates a new issue for the current repository.


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4.3.4 Editing Topics and Posts

We call both issues and pull-requests "topics". The contributions to the conversation are called "posts". The post that initiated the conversation is also called a post.

These commands are available only from the topic buffer (i.e. from the buffer that shows the posts on a topic). Other commands that also work in other buffers are available here also. For example C-c C-w on a post visits that post in a browser.

C-c C-n     (forge-create-post)
C-c C-r     (forge-create-post)

This command allows users to create a new post on an existing topic. It opens a buffer in which the user can write the post. When the post is done, then the user has to sumbit using C-c C-c.

C-c C-e [on a post section]     (forge-edit-post)

This command visits an existing post in a separate buffer. When the changes to the post are done, then the user has to sumbit using C-c C-c.

C-c C-e [on "Title" section]     (forge-edit-topic-title)

This command reads a new title for an existing topic in the minibuffer.

C-c C-e [on "State" section]     (forge-edit-topic-state)

This command toggles the state of an existing topic between "open" and "closed".

C-c C-e [on "Labels" section]     (forge-edit-topic-labels)

This command reads a list of labels for an existing topic in the minibuffer.

C-c C-e [on "Assignees" section]     (forge-edit-topic-assignees)

This command reads a list of assignees for an existing topic in the minibuffer.

Creating a new post and editing an existing post are similar to creating a new commit and editing the message of an existing commit. In both cases the message has to be written in a separate buffer. And then the process has to be finished or canceled using a separate command.

The following commands are available in buffers used to edit posts:

C-c C-c     (forge-post-submit)

This command submits the post that is being edited in the current buffer.

C-c C-k     (forge-post-cancel)

This command cancels the post that is being edited in the current buffer.


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4.4 Miscellanous

M-x forge-reset-database     (forge-reset-database)

This command moves the current database file to the trash and creates a new empty database.

This is useful after the database’s table schemata have changed, which will happen a few times while the Forge functionality is still under heavy development.