Added tests for Pathname to read_parquet and write_parquet

lib/polars/data_frame.rb

@@ -1060,7 +1060,7 @@ def write_ipc(file, compression: "uncompressed")
 
     # Write to Apache Parquet file.
     #
-    # @param file [String, StringIO]
+    # @param file [String, Pathname, StringIO]
     #   File path to which the file should be written.
     # @param compression ["lz4", "uncompressed", "snappy", "gzip", "lzo", "brotli", "zstd"]
     #   Choose "zstd" for good compression performance.

lib/polars/io.rb

@@ -520,7 +520,7 @@ def read_ipc(
 
     # Read into a DataFrame from a parquet file.
     #
-    # @param source [Object]
+    # @param source [String, Pathname, StringIO]
     #   Path to a file or a file-like object.
     # @param columns [Object]
     #   Columns to select. Accepts a list of column indices (starting at zero) or a list

test/parquet_test.rb

@@ -13,6 +13,14 @@ def test_read_parquet_file
     assert_frame expected, df
   end
 
+  def test_read_parquet_pathname
+    require "pathname"
+
+    df = Polars.read_parquet(Pathname.new("test/support/data.parquet"))
+    expected = Polars::DataFrame.new({"a" => [1, 2, 3], "b" => ["one", "two", "three"]})
+    assert_frame expected, df
+  end
+
   def test_read_parquet_io
     require "stringio"
 
@@ -43,6 +51,13 @@ def test_write_parquet
     assert_nil df.write_parquet(temp_path)
   end
 
+  def test_write_parquet_pathname
+    require "pathname"
+
+    df = Polars::DataFrame.new({"a" => [1, 2, 3], "b" => ["one", "two", "three"]})
+    assert_nil df.write_parquet(Pathname.new(temp_path))
+  end
+
   def test_write_parquet_io
     require "stringio"