Push cwd handling all the way up in mix format

2 files changed, 45 insertions, 62 deletions

diff --git a/lib/mix/lib/mix/tasks/format.ex b/lib/mix/lib/mix/tasks/format.ex
index a164f3aac..ff0ab84d4 100644
--- a/lib/mix/lib/mix/tasks/format.ex
+++ b/lib/mix/lib/mix/tasks/format.ex
@@ -218,8 +218,9 @@ defmodule Mix.Tasks.Format do
 
   @impl true
   def run(args) do
+    cwd = File.cwd!()
     {opts, args} = OptionParser.parse!(args, strict: @switches)
-    {dot_formatter, formatter_opts} = eval_dot_formatter(opts)
+    {dot_formatter, formatter_opts} = eval_dot_formatter(cwd, opts)
 
     if opts[:check_equivalent] do
       IO.warn("--check-equivalent has been deprecated and has no effect")
@@ -230,10 +231,10 @@ defmodule Mix.Tasks.Format do
     end
 
     {formatter_opts_and_subs, _sources} =
-      eval_deps_and_subdirectories(dot_formatter, [], formatter_opts, [dot_formatter])
+      eval_deps_and_subdirectories(cwd, dot_formatter, formatter_opts, [dot_formatter])
 
     args
-    |> expand_args(dot_formatter, formatter_opts_and_subs, opts)
+    |> expand_args(cwd, dot_formatter, formatter_opts_and_subs, opts)
     |> Task.async_stream(&format_file(&1, opts), ordered: false, timeout: :infinity)
     |> Enum.reduce({[], []}, &collect_status/2)
     |> check!(opts)
@@ -249,14 +250,13 @@ defmodule Mix.Tasks.Format do
   """
   @doc since: "1.13.0"
   def formatter_for_file(file, opts \\ []) do
-    {dot_formatter, formatter_opts} = eval_dot_formatter(opts)
-
-    prefix = Keyword.get(opts, :root, [])
+    cwd = Keyword.get_lazy(opts, :root, &File.cwd!/0)
+    {dot_formatter, formatter_opts} = eval_dot_formatter(cwd, opts)
 
     {formatter_opts_and_subs, _sources} =
-      eval_deps_and_subdirectories(dot_formatter, prefix, formatter_opts, [dot_formatter])
+      eval_deps_and_subdirectories(cwd, dot_formatter, formatter_opts, [dot_formatter])
 
-    find_formatter_and_opts_for_file(file, prefix, formatter_opts_and_subs)
+    find_formatter_and_opts_for_file(file, cwd, formatter_opts_and_subs)
   end
 
   @doc """
@@ -269,17 +269,14 @@ defmodule Mix.Tasks.Format do
     formatter_opts
   end
 
-  defp eval_dot_formatter(opts) do
+  defp eval_dot_formatter(cwd, opts) do
     cond do
       dot_formatter = opts[:dot_formatter] ->
         {dot_formatter, eval_file_with_keyword_list(dot_formatter)}
 
-      File.regular?(".formatter.exs") ->
-        {".formatter.exs", eval_file_with_keyword_list(".formatter.exs")}
-
-      opts[:root] && File.regular?(Path.join(opts[:root], ".formatter.exs")) ->
-        dot_formatter = Path.join(opts[:root], ".formatter.exs")
-        {dot_formatter, eval_file_with_keyword_list(dot_formatter)}
+      File.regular?(Path.join(cwd, ".formatter.exs")) ->
+        dot_formatter = Path.join(cwd, ".formatter.exs")
+        {".formatter.exs", eval_file_with_keyword_list(dot_formatter)}
 
       true ->
         {".formatter.exs", []}
@@ -289,7 +286,7 @@ defmodule Mix.Tasks.Format do
   # This function reads exported configuration from the imported
   # dependencies and subdirectories and deals with caching the result
   # of reading such configuration in a manifest file.
-  defp eval_deps_and_subdirectories(dot_formatter, prefix, formatter_opts, sources) do
+  defp eval_deps_and_subdirectories(cwd, dot_formatter, formatter_opts, sources) do
     deps = Keyword.get(formatter_opts, :import_deps, [])
     subs = Keyword.get(formatter_opts, :subdirectories, [])
     plugins = Keyword.get(formatter_opts, :plugins, [])
@@ -356,7 +353,7 @@ defmodule Mix.Tasks.Format do
 
       {{locals_without_parens, subdirectories}, sources} =
         maybe_cache_in_manifest(dot_formatter, manifest, fn ->
-          {subdirectories, sources} = eval_subs_opts(subs, prefix, sources)
+          {subdirectories, sources} = eval_subs_opts(subs, cwd, sources)
           {{eval_deps_opts(deps), subdirectories}, sources}
         end)
 
@@ -420,11 +417,11 @@ defmodule Mix.Tasks.Format do
         do: parenless_call
   end
 
-  defp eval_subs_opts(subs, prefix, sources) do
+  defp eval_subs_opts(subs, cwd, sources) do
     {subs, sources} =
       Enum.flat_map_reduce(subs, sources, fn sub, sources ->
-        prefix = Path.join(prefix ++ [sub])
-        {Path.wildcard(prefix), [Path.join(prefix, ".formatter.exs") | sources]}
+        cwd = Path.expand(sub, cwd)
+        {Path.wildcard(cwd), [Path.join(cwd, ".formatter.exs") | sources]}
       end)
 
     Enum.flat_map_reduce(subs, sources, fn sub, sources ->
@@ -434,7 +431,7 @@ defmodule Mix.Tasks.Format do
         formatter_opts = eval_file_with_keyword_list(sub_formatter)
 
         {formatter_opts_and_subs, sources} =
-          eval_deps_and_subdirectories(:in_memory, [sub], formatter_opts, sources)
+          eval_deps_and_subdirectories(sub, :in_memory, formatter_opts, sources)
 
         {[{sub, formatter_opts_and_subs}], sources}
       else
@@ -470,7 +467,7 @@ defmodule Mix.Tasks.Format do
     opts
   end
 
-  defp expand_args([], dot_formatter, formatter_opts_and_subs, _opts) do
+  defp expand_args([], cwd, dot_formatter, formatter_opts_and_subs, _opts) do
     if no_entries_in_formatter_opts?(formatter_opts_and_subs) do
       Mix.raise(
         "Expected one or more files/patterns to be given to mix format " <>
@@ -479,13 +476,13 @@ defmodule Mix.Tasks.Format do
     end
 
     dot_formatter
-    |> expand_dot_inputs([], formatter_opts_and_subs, %{})
+    |> expand_dot_inputs(cwd, formatter_opts_and_subs, %{})
     |> Enum.map(fn {file, {_dot_formatter, formatter_opts}} ->
       {file, find_formatter_for_file(file, formatter_opts)}
     end)
   end
 
-  defp expand_args(files_and_patterns, _dot_formatter, {formatter_opts, subs}, opts) do
+  defp expand_args(files_and_patterns, cwd, _dot_formatter, {formatter_opts, subs}, opts) do
     files =
       for file_or_pattern <- files_and_patterns,
           file <- stdin_or_wildcard(file_or_pattern),
@@ -504,35 +501,34 @@ defmodule Mix.Tasks.Format do
         stdin_filename = Keyword.get(opts, :stdin_filename, "stdin.exs")
 
         {formatter, _opts} =
-          find_formatter_and_opts_for_file(stdin_filename, {formatter_opts, subs})
+          find_formatter_and_opts_for_file(stdin_filename, cwd, {formatter_opts, subs})
 
         {file, formatter}
       else
-        {formatter, _opts} = find_formatter_and_opts_for_file(file, {formatter_opts, subs})
+        {formatter, _opts} = find_formatter_and_opts_for_file(file, cwd, {formatter_opts, subs})
         {file, formatter}
       end
     end
   end
 
-  defp expand_dot_inputs(dot_formatter, prefix, {formatter_opts, subs}, acc) do
+  defp expand_dot_inputs(dot_formatter, cwd, {formatter_opts, subs}, acc) do
     if no_entries_in_formatter_opts?({formatter_opts, subs}) do
       Mix.raise("Expected :inputs or :subdirectories key in #{dot_formatter}")
     end
 
     map =
       for input <- List.wrap(formatter_opts[:inputs]),
-          file <- Path.wildcard(Path.join(prefix ++ [input]), match_dot: true),
-          do: {expand_relative_to_cwd(file), {dot_formatter, formatter_opts}},
+          file <- Path.wildcard(Path.expand(input, cwd), match_dot: true),
+          do: {file, {dot_formatter, formatter_opts}},
           into: %{}
 
     acc =
       Map.merge(acc, map, fn file, {dot_formatter1, _}, {dot_formatter2, formatter_opts} ->
         Mix.shell().error(
-          "Both #{dot_formatter1} and #{dot_formatter2} specify the file " <>
-            "#{Path.relative_to_cwd(file)} in their :inputs option. To resolve the " <>
-            "conflict, the configuration in #{dot_formatter1} will be ignored. " <>
-            "Please change the list of :inputs in one of the formatter files so only " <>
-            "one of them matches #{Path.relative_to_cwd(file)}"
+          "Both #{dot_formatter1} and #{dot_formatter2} specify the file #{file} in their " <>
+            ":inputs option. To resolve the conflict, the configuration in #{dot_formatter1} " <>
+            "will be ignored. Please change the list of :inputs in one of the formatter files " <>
+            "so only one of them matches #{file}"
         )
 
         {dot_formatter2, formatter_opts}
@@ -540,17 +536,10 @@ defmodule Mix.Tasks.Format do
 
     Enum.reduce(subs, acc, fn {sub, formatter_opts_and_subs}, acc ->
       sub_formatter = Path.join(sub, ".formatter.exs")
-      expand_dot_inputs(sub_formatter, [sub], formatter_opts_and_subs, acc)
+      expand_dot_inputs(sub_formatter, sub, formatter_opts_and_subs, acc)
     end)
   end
 
-  defp expand_relative_to_cwd(path) do
-    case File.cwd() do
-      {:ok, cwd} -> Path.expand(path, cwd)
-      _ -> path
-    end
-  end
-
   defp find_formatter_for_file(file, formatter_opts) do
     ext = Path.extname(file)
 
@@ -582,22 +571,15 @@ defmodule Mix.Tasks.Format do
     if plugins != [], do: plugins, else: nil
   end
 
-  defp find_formatter_and_opts_for_file(file, formatter_opts_and_subs) do
-    split = file |> Path.relative_to_cwd() |> Path.split()
-    formatter_opts = recur_formatter_opts_for_file(split, formatter_opts_and_subs)
-    {find_formatter_for_file(file, formatter_opts), formatter_opts}
-  end
-
-  defp find_formatter_and_opts_for_file(file, prefix, formatter_opts_and_subs) do
-    split = file |> Path.relative_to(prefix) |> Path.split()
-    formatter_opts = recur_formatter_opts_for_file(split, formatter_opts_and_subs)
+  defp find_formatter_and_opts_for_file(file, cwd, formatter_opts_and_subs) do
+    formatter_opts = recur_formatter_opts_for_file(cwd, formatter_opts_and_subs)
     {find_formatter_for_file(file, formatter_opts), formatter_opts}
   end
 
-  defp recur_formatter_opts_for_file(split, {formatter_opts, subs}) do
+  defp recur_formatter_opts_for_file(cwd, {formatter_opts, subs}) do
     Enum.find_value(subs, formatter_opts, fn {sub, formatter_opts_and_subs} ->
-      if List.starts_with?(split, Path.split(sub)) do
-        recur_formatter_opts_for_file(split, formatter_opts_and_subs)
+      if String.starts_with?(sub, cwd) do
+        recur_formatter_opts_for_file(sub, formatter_opts_and_subs)
       end
     end)
   end
diff --git a/lib/mix/test/mix/tasks/format_test.exs b/lib/mix/test/mix/tasks/format_test.exs
index 05be1212e..d6b6793e9 100644
--- a/lib/mix/test/mix/tasks/format_test.exs
+++ b/lib/mix/test/mix/tasks/format_test.exs
@@ -744,7 +744,7 @@ defmodule Mix.Tasks.FormatTest do
       []
       """)
 
-      message = "Expected :inputs or :subdirectories key in lib/.formatter.exs"
+      message = "Expected :inputs or :subdirectories key in #{Path.expand("lib/.formatter.exs")}"
       assert_raise Mix.Error, message, fn -> Mix.Tasks.Format.run([]) end
     end)
   end
@@ -799,16 +799,17 @@ defmodule Mix.Tasks.FormatTest do
       Mix.Tasks.Format.run([])
 
       message1 =
-        "Both .formatter.exs and lib/.formatter.exs specify the file lib/a.ex in their " <>
-          ":inputs option. To resolve the conflict, the configuration in .formatter.exs " <>
-          "will be ignored. Please change the list of :inputs in one of the formatter files " <>
-          "so only one of them matches lib/a.ex"
+        "Both .formatter.exs and #{Path.expand("lib/.formatter.exs")} specify the file " <>
+          "#{Path.expand("lib/a.ex")} in their :inputs option. To resolve the conflict, " <>
+          "the configuration in .formatter.exs will be ignored. Please change the list of " <>
+          ":inputs in one of the formatter files so only one of them matches #{Path.expand("lib/a.ex")}"
 
       message2 =
-        "Both lib/.formatter.exs and foo/.formatter.exs specify the file lib/a.ex in their " <>
-          ":inputs option. To resolve the conflict, the configuration in lib/.formatter.exs " <>
+        "Both #{Path.expand("lib/.formatter.exs")} and #{Path.expand("foo/.formatter.exs")} " <>
+          "specify the file #{Path.expand("lib/a.ex")} in their :inputs option. To resolve " <>
+          "the conflict, the configuration in #{Path.expand("lib/.formatter.exs")} " <>
           "will be ignored. Please change the list of :inputs in one of the formatter files " <>
-          "so only one of them matches lib/a.ex"
+          "so only one of them matches #{Path.expand("lib/a.ex")}"
 
       assert_received {:mix_shell, :error, [^message1]}
       assert_received {:mix_shell, :error, [^message2]}