BUILD

load("//bzl:fmt.bzl", "fmt")

fmt(name="fmt")

bzl_fmt.bzl

load("@io_bazel_rules_go//go/private:common.bzl", "get_go_toolchain")

_script_content = """
BASE=$(pwd)
WORKSPACE=$(dirname $(readlink WORKSPACE))
cd "$WORKSPACE"
export GOROOT="{goroot}"
gofmt {options} {target}
"""

_script_name = "gofmt.bash"

def _fmt_script_impl(ctx):
  go_toolchain = get_go_toolchain(ctx)
  script_file = ctx.new_file(ctx.label.name + ".bash")
  ctx.file_action(output=script_file, executable=True, content=_script_content.format(
    go=go_toolchain.go.path,
    goroot=go_toolchain.root.path,
    options=ctx.attr.options,
    target=" ".join(ctx.attr.target),
  ))
  return struct(
      files = depset([script_file]),
      runfiles = ctx.runfiles([script_file]),
  )

_fmt_script = rule(
  _fmt_script_impl,
  attrs = {
    "options": attr.string(),
    "target": attr.string_list(),
    "_go_toolchain": attr.label(default = Label("@io_bazel_rules_go_toolchain//:go_toolchain")),
  }
)

def fmt(name, options="-l -w", target=["."]):
  script_name = name + ".bash"
  _fmt_script(
      name = script_name,
      options = options,
      target = target
  )
  native.sh_binary(
      name = name,
      srcs = [script_name],
      data = ["//:WORKSPACE"],
  )