erlware_commons/src/ec_git_vsn.erl
2014-03-28 08:39:26 +01:00

79 lines
2.5 KiB
Erlang

%%% vi:ts=4 sw=4 et
%%%-------------------------------------------------------------------
%%% @author Eric Merritt <ericbmerritt@gmail.com>
%%% @copyright 2011 Erlware, LLC.
%%% @doc
%%% This provides an implementation of the ec_vsn for git. That is
%%% it is capable of returning a semver for a git repository
%%% see ec_vsn
%%% see ec_semver
%%% @end
%%%-------------------------------------------------------------------
-module(ec_git_vsn).
-behaviour(ec_vsn).
%% API
-export([new/0,
vsn/1]).
-export_type([t/0]).
%%%===================================================================
%%% Types
%%%===================================================================
%% This should be opaque, but that kills dialyzer so for now we export it
%% however you should not rely on the internal representation here
-type t() :: {}.
%%%===================================================================
%%% API
%%%===================================================================
-spec new() -> t().
new() ->
{}.
-spec vsn(t()) -> {ok, string()} | {error, Reason::any()}.
vsn(_Data) ->
Result = do_cmd("git describe --tags --always"),
case re:split(Result, "-") of
[Vsn, Count, RefTag] ->
erlang:iolist_to_binary([strip_leading_v(Vsn),
<<"+build.">>,
Count,
<<".ref.">>,
RefTag]);
[VsnOrRefTag] ->
case re:run(VsnOrRefTag, "^[0-9a-fA-F]+$") of
{match, _} ->
find_vsn_from_start_of_branch(VsnOrRefTag);
nomatch ->
strip_leading_v(VsnOrRefTag)
end;
_ ->
{error, {invalid_result, Result}}
end.
%%%===================================================================
%%% Internal Functions
%%%===================================================================
-spec strip_leading_v(string()) -> string().
strip_leading_v(Vsn) ->
case re:run(Vsn, "v?(.+)", [{capture, [1], binary}]) of
{match, [NVsn]} ->
NVsn;
_ ->
Vsn
end.
-spec find_vsn_from_start_of_branch(string()) -> string().
find_vsn_from_start_of_branch(RefTag) ->
Count = do_cmd("git rev-list HEAD --count"),
erlang:iolist_to_binary(["0.0.0+build.", Count, ".ref.", RefTag]).
do_cmd(Cmd) ->
trim_whitespace(os:cmd(Cmd)).
trim_whitespace(Input) ->
re:replace(Input, "\\s+", "", [global]).