Pass xref's compile args to compile task (#10852)

Author: szajbus

lib/mix/lib/mix/tasks/xref.ex

@@ -191,10 +191,11 @@ defmodule Mix.Tasks.Xref do
 
   @impl true
   def run(args) do
-    {opts, args} = OptionParser.parse!(args, strict: @switches)
     Mix.Task.run("compile", args)
     Mix.Task.reenable("xref")
 
+    {opts, args} = OptionParser.parse!(args, strict: @switches)
+
     case args do
       ["callers", callee] ->
         callers(callee, opts)

lib/mix/test/mix/tasks/xref_test.exs

@@ -587,6 +587,38 @@ defmodule Mix.Tasks.XrefTest do
       end)
     end
 
+    test "compiles project first by default" do
+      in_fixture("no_mixfile", fn ->
+        File.write!("lib/a.ex", """
+        defmodule A do
+          def a, do: :ok
+        end
+        """)
+
+        Mix.Tasks.Xref.run(["graph"])
+
+        assert "Compiling" <> _ = receive_until_no_messages([])
+      end)
+    end
+
+    test "passes args over to compile task" do
+      in_fixture("no_mixfile", fn ->
+        File.write!("lib/a.ex", """
+        defmodule A do
+          def a, do: :ok
+        end
+        """)
+
+        Mix.Task.run("compile")
+        Mix.Task.reenable("compile")
+        Mix.shell().flush()
+
+        Mix.Tasks.Xref.run(["graph", "--no-compile"])
+
+        refute String.starts_with?(receive_until_no_messages([]), "Compiling")
+      end)
+    end
+
     defp assert_graph(opts \\ [], expected) do
       in_fixture("no_mixfile", fn ->
         File.write!("lib/a.ex", """