Updating Go Import Statements using Comby

This guide explains how to use Comby to update Go import statements in a batch change.

This batch change example rewrites Go import paths for the log15 package from gopkg.in/inconshreveable/log15.v2 to github.com/inconshreveable/log15 using Comby.

It can handle single-package import statements like the following:

GO
import "gopkg.in/inconshreveable/log15.v2"

Single-package imports with an alias:

GO
import log15 "gopkg.in/inconshreveable/log15.v2"

And multi-package import statements with or without an alias:

GO
import (
	"io"
 
	"github.com/pkg/errors"
	"gopkg.in/inconshreveable/log15.v2"
)

Prerequisites

It's recommended to use the latest version of Sourcegraph when working with Batch Changes.

Before you start, it's better to read the following docs:

Create the batch spec

Save the following batch spec YAML as update-log15-import.batch.yaml:

YAML
name: update-log15-import
description: This batch change updates Go import paths for the `log15` package from `gopkg.in/inconshreveable/log15.v2` to `github.com/inconshreveable/log15` using [Comby](https://comby.dev/)
 
# Find all repositories that contain the import we want to change.
on:
  - repositoriesMatchingQuery: lang:go gopkg.in/inconshreveable/log15.v2
 
# In each repository
steps:
  # we first replace the import when it's part of a multi-package import statement
  - run: comby -in-place 'import (:[before]"gopkg.in/inconshreveable/log15.v2":[after])' 'import (:[before]"github.com/inconshreveable/log15":[after])' .go -matcher .go -exclude-dir .,vendor
    container: comby/comby
  # ... and when it's a single import line.
  - run: comby -in-place 'import:[alias]"gopkg.in/inconshreveable/log15.v2"' 'import:[alias]"github.com/inconshreveable/log15"' .go -matcher .go -exclude-dir .,vendor
    container: comby/comby
 
# Describe the changeset (e.g., GitHub pull request) you want for each repository.
changesetTemplate:
  title: Update import path for log15 package to use GitHub
  body: Updates Go import paths for the `log15` package from `gopkg.in/inconshreveable/log15.v2` to `github.com/inconshreveable/log15` using [Comby](https://comby.dev/)
  branch: batch-changes/update-log15-import # Push the commit to this branch.
  commit:
    message: Fix import path for log15 package
  published: false

Create the batch change

In your terminal, run the following command:

SHELL
src batch preview -f update-log15-import.batch.yaml

Wait for it to run and compute the changes for each repository
Open the preview URL that the command printed out
Examine the preview. Confirm that the changesets are the ones you intended to track. If not, edit the batch spec and then re-run the command above
Click the Apply button to create the batch change
Feel free to then publish the changesets (i.e., create pull requests and merge requests) by modifying the published attribute in the batch spec and re-running the src batch preview command