Batch Spec Cheatsheet

This cheatsheet is a quick reference for common batch change use cases.

Some common patterns are reused every time when writing batch specs. This documentation lists these patterns to make it easy for you to copy and reuse them. You can also refer to the batch change examples repo for more consolidated examples of batch specs.

It's also recommended to see batch spec templating since most of these examples use templating.

Loop over search result paths in shell script

YAML
on:
  - repositoriesMatchingQuery: OLD-VALUE
 
steps:
  - run: |
      for file in "${{ join repository.search_result_paths " " }}";
      do
        sed -i 's/OLD-VALUE/NEW-VALUE/g;' ${file}
      done
    container: alpine:3

Put search result paths in file and loop over them

YAML
on:
  - repositoriesMatchingQuery: OLD-VALUE
 
steps:
  - run: |
      cat /tmp/search-results | while read file;
      do
        sed -i 's/OLD-VALUE/NEW-VALUE/g;' "${file}"
      done
    container: alpine:3
    files:
      /tmp/search-results: ${{ join repository.search_result_paths "\n" }}

Use search result paths as arguments for single command

YAML
on:
  - repositoriesMatchingQuery: lang:go fmt.Sprintf("%d", :[v]) patterntype:structural -file:vendor count:10
 
steps:
  - run: comby -in-place 'fmt.Sprintf("%d", :[v])' 'strconv.Itoa(:[v])' ${{ join repository.search_result_paths " " }}
    container: comby/comby

Format files modified by previous step

YAML
steps:
  - run: comby -in-place 'fmt.Sprintf("%d", :[v])' 'strconv.Itoa(:[v])' ${{ join repository.search_result_paths " " }}
    container: comby/comby
  - run: goimports -w ${{ join previous_step.modified_files " " }}
    container: unibeautify/goimports

Dynamically set branch name based on workspace

YAML
workspaces:
  - rootAtLocationOf: package.json
    in: github.com/sourcegraph/*
 
steps:
  # [... other steps ... ]
  - run:  if [[ -f "package.json" ]]; then cat package.json | jq -j .name; fi
    container: jiapantw/jq-alpine:latest
    outputs:
      projectName:
        value: ${{ step.stdout }}
 
changesetTemplate:
  # [...]
 
  # If we have an `outputs.projectName` we use it, otherwise we append the path
  # of the workspace. If the path is emtpy (as is the case in the root folder),
  # we ignore it.
  branch: |
    ${{ if eq outputs.projectName "" }}
    ${{ join_if "-" "thorsten/workspace-discovery" (replace steps.path "/" "-") }}
    ${{ else }}
    thorsten/workspace-discovery-${{ outputs.projectName }}
    ${{ end }}

Process search result paths with script

YAML
steps:
  - run: |
      for result in "${{ join repository.search_result_paths " " }}"; do
        ruby /tmp/script "${result}" > "${result}.new"
        mv ${result}.new "${result}"
      done;
    container: ruby
    files:
      /tmp/script: |
        #! /usr/bin/env ruby
        require 'yaml';
        content = YAML.load(ARGF.read)
        content['batchchanges'] = 'say hello'
        puts YAML.dump(content)

Use separate file as config file for command

YAML
steps:
  - run: comby -in-place -matcher .go -config /tmp/comby-conf.toml -f ${{ join repository.search_result_paths "," }}
    container: comby/comby
    files:
      /tmp/comby-conf.toml: |
        [log_to_log15]
        match='log.Printf(":[format]", :[args])'
        rewrite='log15.Warn(":[format]", :[args])'
        rule='where
        rewrite :[format] { "%:[[_]] " -> "" },
        rewrite :[format] { " %:[[_]]" -> "" },
        rewrite :[args] { ":[arg~[a-zA-Z0-9.()]+]" -> "\":[arg]\", :[arg]" }'

Publish only changesets on specific branches

YAML
changesetTemplate:
  # [...]
  published:
    - github.com/my-org/my-repo@my-branch-name: draft

Create new files in repository

YAML
steps:
  - run: cat /tmp/global-gitignore >> .gitignore
    container: alpine:3
    files:
      /tmp/global-gitignore: |
        # Vim
        *.swp
        # JetBrains/IntelliJ
        .idea
        # Emacs
        *~
        \#*\#
        /.emacs.desktop
        /.emacs.desktop.lock
        .\#*
        .dir-locals.el

Execute steps only in repositories matching name

YAML
steps:
  # [... other steps ...]
  - run: echo "name contains sourcegraph-testing" >> message.txt
    if: ${{ matches repository.name "*sourcegraph-testing*" }}
    container: alpine:3

Execute steps based on output of previous command

YAML
steps:
  - run:  if [[ -f "go.mod" ]]; then echo "true"; else echo "false"; fi
    container: alpine:3
    outputs:
      goModExists:
        value: ${{ step.stdout }}
 
  - run: go fmt ./...
    container: golang
    if: ${{ outputs.goModExists }}

Write a GitHub Actions workflow that includes GitHub expression syntax

YAML
steps:
  - container: alpine:3
    run: |
      #!/usr/bin/env bash
 
      mkdir -p .github/workflows
 
      cat <<EOF >.github/workflows/scip.yml
      name: Index
      on:
        - push
      jobs:
        scip-go:
          runs-on: ubuntu-latest
          container: sourcegraph/scip-go
          steps:
            - uses: actions/checkout@v1
            - name: Generate SCIP data
              run: scip-go
            - name: Install src CLI
              run: |
                  curl -L https://sourcegraph.com/.api/src-cli/src_linux_amd64 -o /usr/local/bin/src
                  chmod +x /usr/local/bin/src
            - name: Upload SCIP data
              run: src code-intel upload -github-token=${{ "\\${{secrets.GITHUB_TOKEN}}" }}
      EOF

Since GitHub expression syntax conflicts with Sourcegraph's own template expression syntax, including the expression again as a quoted string within a template expression means that the inner expression will be output as a string (effectively, ignoring the contents of the inner expression).

For run: fields specifically, to avoid the shell also interpreting the GitHub expression as a variable when executing the script, you need to escape the quoted $ with two backslashes: first for the shell script itself, and second to escape the backslash within the template expression string.

To use the literal sequence ${{ }} in non-run: fields of the batch spec that supports templating, quoted strings are normally sufficient: ${{ "${{ leave me alone! }}" }}

List what files were modified by the batch change in the changeset

YAML
changesetTemplate:
  title: A batch change
  body: |
    This batch change modifies:
      ${{ range $index, $file := steps.modified_files }}
       - ${{ $file }}
      ${{ end }}