Developing campaigns

What are code change campaigns?

Before diving into the technical part of campaigns, make sure to read up on what code campaigns are, what it's not and what we want it to be:

Start by reading through the code change management product page
IMPORTANT: Watch the videos! At the bottom of that page, you'll find two demo videos. A lot of our work aims to reproduce what you can see in these videos — in a scalable way that supports multiple code hosts. Make sure to watch these videos!
Take a look at the sequence of milestones to get a high-level overview of what we did so far and what still needs to be done
Read through the user documentation.

Starting up your environment

Run ./enterprise/dev/start.sh — Wait until all repositories are cloned.
Follow the user guide on creating campaigns. Remember: If you create a campaign, you're opening real PRs on GitHub. Make sure only testing repositories are affected. If you create a large campaign, it takes a while to preview/create but also helps a lot with finding bugs/errors, etc.

Glossary

The code campaigns feature introduces a lot of new names, GraphQL queries and mutations and database tables. This section tries to explain the most common names and provide a mapping between the GraphQL types and their internal counterpart in the Go backend.

GraphQL type	Go type	Database table	Description
`Campaign`	`campaigns.Campaign`	`campaigns`	A campaign is a collection of changesets on code hosts. The central entity.
`ExternalChangeset`	`campaigns.Changeset`	`changesets`	Changeset is the unified name for pull requests/merge requests/etc. on code hosts.
`CampaignPlan`	`campaigns.CampaignPlan`	`campaign_plans`	A campaign plan is a collection of changes (think: patches/diffs) that will be applied by running a Campaign. A campaign has one campaign plan.
`ChangesetPlan`	`campaigns.CampaignJob`	`campaign_jobs`	A plan for a changeset. It represents a patch per repository that can be a changeset. It belongs to a campaign plan, which has multiple changeset plans, one per repository.
-	`campaigns.ChangesetJob`	`changeset_jobs`	It represents the process of turning a `ChangesetPlan` (GraphQL)/`campaigns.CampaignJob` (Go) into a `Changeset` on the code host. It is executed asynchronously in the background when a campaign is created with a campaign plan.
`ChangesetEvent`	`campaigns.ChangesetEvent`	`changeset_events`	A changeset event is an event on a code host, e.g. a comment or a review on a pull request on GitHub. They are created by syncing the changesets from the code host on a regular basis and by accepting webhook events and turning them into changeset events.

Diving into the code as a backend developer

Read through ./cmd/frontend/graphqlbackend/campaigns.go to get an overview of the campaigns GraphQL API.
Read through ./internal/campaigns/types.go to see all campaigns-related type definitions.
Compare that with the GraphQL definitions in ./cmd/frontend/graphqlbackend/schema.graphql.
Start reading through ./enterprise/internal/campaigns/resolvers/resolver.go to see how the main mutation are implemented (look at createCampaignPlanFromPatches and createCampaign to see how the two main operations are implemented).
Then start from the other end, enterprise/cmd/repo-updater/main.go, and see how the enterprise repo-updater uses campaigns.Syncer to sync Changesets.

GitHub testing account

The campaigns feature requires creating changesets (PRs) on code hosts. If you are not part of the Sourcegraph organization, we recommend you create dummy projects to safely test changes on so you do not spam real repositories with your tests. If you are part of the Sourcegraph organization, we have an account set up for this purpose.

To use this account, follow these steps:

Find the GitHub sd9 user in 1Password
Copy the Campaigns Testing Token
Change your dev-private/enterprise/dev/external-services-config.json to only contain a GitHub config with the token, like this:

{
  "GITHUB": [
    {
      "authorization": {},
      "url": "https://github.com",
      "token": "<TOKEN>",
      "repositoryQuery": ["affiliated"]
    }
  ]
}