feat: allow elixir scripts for data extension (#25)

Author: mhanberg

lib/tableau/data.ex

@@ -22,13 +22,23 @@ defmodule Tableau.DataExtension do
 
   def run(token) do
     data =
-      for file <- Path.wildcard(Path.join(token.data.dir, "**/*.{yml,yaml}")), into: %{} do
-        key =
-          file
-          |> Path.basename(".yaml")
-          |> Path.basename(".yml")
+      for file <- Path.wildcard(Path.join(token.data.dir, "**/*.{yml,yaml,exs}")), into: %{} do
+        case Path.extname(file) do
+          ".exs" ->
+            key = file |> Path.basename(".exs")
 
-        {key, YamlElixir.read_from_file!(file)}
+            {result, _binding} = Code.eval_file(file)
+
+            {key, result}
+
+          yaml when yaml in ~w[.yml .yaml] ->
+            key =
+              file
+              |> Path.basename(".yaml")
+              |> Path.basename(".yml")
+
+            {key, YamlElixir.read_from_file!(file)}
+        end
       end
 
     {:ok, Map.put(token, :data, data)}

lib/tableau/extensions/data_extension.ex

@@ -0,0 +1,5 @@
+%{
+  foo: [
+    "bar"
+  ]
+}

test/support/fixtures/foobar.exs

@@ -3,13 +3,16 @@ defmodule Tableau.DataExtensionTest do
 
   alias Tableau.DataExtension
 
-  test "reads files from disk" do
+  test "reads/evals files from disk" do
     token = %{data: %{dir: "test/support/fixtures"}}
 
     assert {:ok, actual} = DataExtension.run(token)
 
     assert actual == %{
              data: %{
+               "foobar" => %{
+                 foo: ["bar"]
+               },
                "books" => %{
                  "books" => [
                    %{"author" => "Michael Crichton", "name" => "Jurassic Park"},