function name changes:

`reduce_path/1` -> `canonical_path/1`
`relative_path/2` -> `path_from_ancestor/2`

src/rebar_dir.erl

@@ -175,15 +175,15 @@ retarget_path(State, Path) ->
 %% not relative to any apps in project, check to see it's relative to
 %% project root
 retarget_path(State, Path, []) ->
-    case rebar_file_utils:relative_path(rebar_file_utils:reduce_path(Path), rebar_state:dir(State)) of
-        {ok, NewPath}         -> filename:join([base_dir(State), NewPath]);
+    case rebar_file_utils:path_from_ancestor(rebar_file_utils:canonical_path(Path), rebar_state:dir(State)) of
+        {ok, NewPath}      -> filename:join([base_dir(State), NewPath]);
         %% not relative to project root, don't modify
-        {error, not_relative} -> Path
+        {error, badparent} -> Path
     end;
 %% relative to current app, retarget to the same dir relative to
 %% the app's out_dir
 retarget_path(State, Path, [App|Rest]) ->
-    case rebar_file_utils:relative_path(rebar_file_utils:reduce_path(Path), rebar_app_info:dir(App)) of
-        {ok, NewPath}         -> filename:join([rebar_app_info:out_dir(App), NewPath]);
-        {error, not_relative} -> retarget_path(State, Path, Rest)
+    case rebar_file_utils:path_from_ancestor(rebar_file_utils:canonical_path(Path), rebar_app_info:dir(App)) of
+        {ok, NewPath}      -> filename:join([rebar_app_info:out_dir(App), NewPath]);
+        {error, badparent} -> retarget_path(State, Path, Rest)
     end.

src/rebar_file_utils.erl

@@ -38,8 +38,8 @@
          system_tmpdir/1,
          reset_dir/1,
          touch/1,
-         relative_path/2,
-         reduce_path/1]).
+         path_from_ancestor/2,
+         canonical_path/1]).
 
 -include("rebar.hrl").
 
@@ -247,29 +247,29 @@ touch(Path) ->
                                                 atime = calendar:local_time()}).
 
 %% for a given path return the path relative to a base directory
--spec relative_path(string(), string()) -> {ok, string()} | {error, not_relative}.
+-spec path_from_ancestor(string(), string()) -> {ok, string()} | {error, badparent}.
 
-relative_path(Target, To) ->
-    relative_path1(filename:split(reduce_path(Target)),
-                   filename:split(reduce_path(To))).
+path_from_ancestor(Target, To) ->
+    path_from_ancestor_(filename:split(canonical_path(Target)),
+                        filename:split(canonical_path(To))).
 
-relative_path1([Part|Target], [Part|To]) -> relative_path1(Target, To);
-relative_path1([], [])                   -> {ok, ""};
-relative_path1(Target, [])               -> {ok, filename:join(Target)};
-relative_path1(_, _)                     -> {error, not_relative}.
+path_from_ancestor_([Part|Target], [Part|To]) -> path_from_ancestor_(Target, To);
+path_from_ancestor_([], [])                   -> {ok, ""};
+path_from_ancestor_(Target, [])               -> {ok, filename:join(Target)};
+path_from_ancestor_(_, _)                     -> {error, badparent}.
 
 
 %% reduce a filepath by removing all incidences of `.' and `..'
--spec reduce_path(string()) -> string().
+-spec canonical_path(string()) -> string().
 
-reduce_path(Dir) -> reduce_path([], filename:split(filename:absname(Dir))).
+canonical_path(Dir) -> canonical_path([], filename:split(filename:absname(Dir))).
 
-reduce_path([], [])                -> filename:nativename("/");
-reduce_path(Acc, [])               -> filename:join(lists:reverse(Acc));
-reduce_path(Acc, ["."|Rest])       -> reduce_path(Acc, Rest);
-reduce_path([_|Acc], [".."|Rest])  -> reduce_path(Acc, Rest);
-reduce_path([], [".."|Rest])       -> reduce_path([], Rest);
-reduce_path(Acc, [Component|Rest]) -> reduce_path([Component|Acc], Rest).
+canonical_path([], [])                -> filename:nativename("/");
+canonical_path(Acc, [])               -> filename:join(lists:reverse(Acc));
+canonical_path(Acc, ["."|Rest])       -> canonical_path(Acc, Rest);
+canonical_path([_|Acc], [".."|Rest])  -> canonical_path(Acc, Rest);
+canonical_path([], [".."|Rest])       -> canonical_path([], Rest);
+canonical_path(Acc, [Component|Rest]) -> canonical_path([Component|Acc], Rest).
 
 %% ===================================================================
 %% Internal functions

test/rebar_file_utils_SUITE.erl

@@ -11,8 +11,8 @@
          reset_nonexistent_dir/1,
          reset_empty_dir/1,
          reset_dir/1,
-         relative_path/1,
-         reduce_path/1]).
+         path_from_ancestor/1,
+         canonical_path/1]).
 
 -include_lib("common_test/include/ct.hrl").
 -include_lib("eunit/include/eunit.hrl").
@@ -22,7 +22,7 @@
 all() ->
     [{group, tmpdir},
      {group, reset_dir},
-     relative_path, reduce_path].
+     path_from_ancestor, canonical_path].
 
 groups() ->
     [{tmpdir, [], [raw_tmpdir, empty_tmpdir, simple_tmpdir, multi_tmpdir]},
@@ -88,19 +88,19 @@ reset_dir(Config) ->
     ?assert(filelib:is_dir(TmpDir)),
     {ok, []} = file:list_dir(TmpDir).
 
-relative_path(_Config) ->
-    ?assertEqual({ok, "foo/bar/baz"}, rebar_file_utils:relative_path("/foo/bar/baz", "/")),
-    ?assertEqual({ok, "bar/baz"}, rebar_file_utils:relative_path("/foo/bar/baz", "/foo")),
-    ?assertEqual({ok, "bar"}, rebar_file_utils:relative_path("foo/bar", "foo")),
-    ?assertEqual({ok, "bar"}, rebar_file_utils:relative_path("foo/bar/", "foo/")),
-    ?assertEqual({error, not_relative}, rebar_file_utils:relative_path("/foo/bar/baz", "/qux")),
-    ?assertEqual({error, not_relative}, rebar_file_utils:relative_path("/foo/bar/baz", "/foo/bar/baz/qux")).
+path_from_ancestor(_Config) ->
+    ?assertEqual({ok, "foo/bar/baz"}, rebar_file_utils:path_from_ancestor("/foo/bar/baz", "/")),
+    ?assertEqual({ok, "bar/baz"}, rebar_file_utils:path_from_ancestor("/foo/bar/baz", "/foo")),
+    ?assertEqual({ok, "bar"}, rebar_file_utils:path_from_ancestor("foo/bar", "foo")),
+    ?assertEqual({ok, "bar"}, rebar_file_utils:path_from_ancestor("foo/bar/", "foo/")),
+    ?assertEqual({error, badparent}, rebar_file_utils:path_from_ancestor("/foo/bar/baz", "/qux")),
+    ?assertEqual({error, badparent}, rebar_file_utils:path_from_ancestor("/foo/bar/baz", "/foo/bar/baz/qux")).
 
-reduce_path(_Config) ->
-    ?assertEqual("/", rebar_file_utils:reduce_path("/")),
-    ?assertEqual("/", rebar_file_utils:reduce_path("/../../..")),
-    ?assertEqual("/foo", rebar_file_utils:reduce_path("/foo/bar/..")),
-    ?assertEqual("/foo", rebar_file_utils:reduce_path("/foo/../foo")),
-    ?assertEqual("/foo", rebar_file_utils:reduce_path("/foo/.")),
-    ?assertEqual("/foo", rebar_file_utils:reduce_path("/foo/./.")),
-    ?assertEqual("/foo/bar", rebar_file_utils:reduce_path("/foo/./bar")).
+canonical_path(_Config) ->
+    ?assertEqual("/", rebar_file_utils:canonical_path("/")),
+    ?assertEqual("/", rebar_file_utils:canonical_path("/../../..")),
+    ?assertEqual("/foo", rebar_file_utils:canonical_path("/foo/bar/..")),
+    ?assertEqual("/foo", rebar_file_utils:canonical_path("/foo/../foo")),
+    ?assertEqual("/foo", rebar_file_utils:canonical_path("/foo/.")),
+    ?assertEqual("/foo", rebar_file_utils:canonical_path("/foo/./.")),
+    ?assertEqual("/foo/bar", rebar_file_utils:canonical_path("/foo/./bar")).