Environment

• Elixir & Erlang versions (elixir --version): elixir 1.4.0, Erlang 19
• Operating system: OSX 10.12.1

Current behavior

I am opening an utf-8 file with File.stream! with the default setting (read lines) like

File.stream!("my_file.txt")
> Enum.map(...)

When trying to match the first line to something expected it fails. It took me quite long to find out that the first line contains 3 extra bytes in the beginning (the BOM, https://de.wikipedia.org/wiki/Byte_Order_Mark).

I solved it in my project with adding the BOM to the expectation

<<239, 187, 191>> <> "HEADER" = line

This might be brittle (when the BOM changes) and confusing.

Expected behavior

When using :line mode or (as Jose suggested at elixirforum) another option :strip_bom is given, the bom should be skipped.