From 12afcb98edc34f1ea243b2121126afc48dd70ec9 Mon Sep 17 00:00:00 2001
From: Wojtek Mach <wojtek@wojtekmach.pl>
Date: Thu, 7 Aug 2025 15:26:03 +0200
Subject: [PATCH 1/2] Improve error message on invalid headers

---
 lib/hpax.ex | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/lib/hpax.ex b/lib/hpax.ex
index 91c9401..bc271f9 100644
--- a/lib/hpax.ex
+++ b/lib/hpax.ex
@@ -298,7 +298,8 @@ defmodule HPAX do
   end
 
   defp encode_headers([{action, name, value} | rest], table, acc)
-       when action in @valid_header_actions and is_binary(name) and is_binary(value) do
+       when action in @valid_header_actions do
+    validate_header(name, value)
     huffman? = table.huffman_encoding == :always
 
     {encoded, table} =
@@ -330,6 +331,15 @@ defmodule HPAX do
     encode_headers(rest, table, [acc, encoded])
   end
 
+  defp validate_header(name, value) when is_binary(name) and is_binary(value) do
+    :ok
+  end
+
+  defp validate_header(name, value) do
+    raise ArgumentError,
+          "expected header name/value to be strings, got: #{inspect(name)}/#{inspect(value)}"
+  end
+
   defp encode_indexed_header(index) do
     <<1::1, Types.encode_integer(index, 7)::bitstring>>
   end

From 138451c6e3952dc77e541617d229a7e614bc0940 Mon Sep 17 00:00:00 2001
From: Wojtek Mach <wojtek@wojtekmach.pl>
Date: Thu, 7 Aug 2025 17:34:50 +0200
Subject: [PATCH 2/2] Add test

---
 test/hpax_test.exs | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)

diff --git a/test/hpax_test.exs b/test/hpax_test.exs
index 72bcc68..5d1da24 100644
--- a/test/hpax_test.exs
+++ b/test/hpax_test.exs
@@ -95,6 +95,22 @@ defmodule HPAXTest do
     assert dec_table.entries == [{"b", "B"}, {"a", "A"}]
   end
 
+  test "encode/3 with invalid headers" do
+    table = HPAX.new(1000)
+
+    assert_raise ArgumentError,
+                 ~s(expected header name/value to be strings, got: :foo/"bar"),
+                 fn ->
+                   HPAX.encode([{:store, :foo, "bar"}], table)
+                 end
+
+    assert_raise ArgumentError,
+                 ~s(expected header name/value to be strings, got: "foo"/:bar),
+                 fn ->
+                   HPAX.encode([{:store, "foo", :bar}], table)
+                 end
+  end
+
   property "encode/3 with a single action" do
     table = HPAX.new(500)