Check duplicate keys dataframe rename column

lib/explorer/data_frame.ex

@@ -3610,6 +3610,10 @@ defmodule Explorer.DataFrame do
 
       pairs ->
         pairs_map = Map.new(pairs)
+
+        if Enum.count(pairs) != map_size(pairs_map),
+          do: raise(ArgumentError, "duplicate source column for rename")
+
         old_dtypes = df.dtypes
 
         for {name, _} <- pairs do

native/explorer/src/dataframe.rs

@@ -533,7 +533,7 @@ pub fn df_rename_columns(
 ) -> Result<ExDataFrame, ExplorerError> {
     let mut df = df.clone();
     for (original, new_name) in renames {
-        df.rename(original, new_name).expect("should rename");
+        df.rename(original, new_name)?;
     }
 
     Ok(ExDataFrame::new(df))

test/explorer/data_frame_test.exs

@@ -2763,6 +2763,38 @@ defmodule Explorer.DataFrameTest do
       end
     end
 
+    test "with keyword and a column that is duplicated" do
+      df = DF.new(a: [1, 2, 3], b: ["a", "b", "c"])
+
+      assert_raise ArgumentError, ~r"duplicate source column for rename", fn ->
+        DF.rename(df, a: "first", a: "second")
+      end
+    end
+
+    test "with mix of column name and index that is duplicated" do
+      df = DF.new(a: [1, 2, 3], b: ["a", "b", "c"])
+
+      assert_raise ArgumentError, ~r"duplicate source column for rename", fn ->
+        DF.rename(df, [{"a", "first"}, {0, "g"}])
+      end
+    end
+
+    test "with string column names that are duplicated" do
+      df = DF.new(a: [1, 2, 3], b: ["a", "b", "c"])
+
+      assert_raise ArgumentError, ~r"duplicate source column for rename", fn ->
+        DF.rename(df, [{"a", "first"}, {"a", "second"}])
+      end
+    end
+
+    test "with string column names and a target that is duplicated" do
+      df = DF.new(a: [1, 2, 3], b: ["a", "b", "c"])
+
+      assert_raise RuntimeError, ~r"duplicate column names found", fn ->
+        DF.rename(df, [{"a", "first"}, {"b", "first"}])
+      end
+    end
+
     test "with a map and a column that doesn't exist" do
       df = DF.new(a: [1, 2, 3], b: ["a", "b", "c"])