Biff - A Bazel VCS diffing tool

Biff tries to answer a simple question in your Bazel monorepository.

What Bazel targets were affected by my VCS changeset?

Bazel can't answer this question because it does not have any information about your VCS setup.

How do I use this thing

You can run the tool straight from this repo by running

./bazel run //:biff -- <OPTIONS HERE>

or you can build the tool and copy the binary from bazel-bin

./bazel build //:biff

cp bazel-bin/biff_/biff <YOUR LOCATION>

biff <OPTIONS HERE>

Commands

Calculate

Calculates the sha256 checksum for each target in the graph and outputs it to a file. This file can then be diffed against another output with the compare command

Usage:

  biff calculate [flags]

Flags:

      --bazel string       Location of Bazel executable. By default uses bazel from path
  -h, --help               help for calculate
      --out string         Where the output should be written to (Required)
      --workspace string   Path to the workspace root (Required)

Compare

Compares two outputs from the calculate command and outputs a file with only the changed targets

Usage:

  biff compare [flags]

Flags:

  -h, --help           help for compare
      --left string    The 'left' side of the comparison (Required)
      --out string     Where the output should be written to (Required)
      --right string   The 'right' side of the comparison (Required)