From fbc7ec76cf1bd4f85dfd003acb5b3457b83f20b2 Mon Sep 17 00:00:00 2001
From: Javier Garea <javigarea@gmail.com>
Date: Mon, 28 Sep 2026 19:22:00 +0200
Subject: [PATCH 1/2] fix: support iodata token values in Lexer.merge/1

---
 lib/makeup/lexer.ex |  2 +-
 test/lexer_test.exs | 28 ++++++++++++++++++++++++++++
 2 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/lib/makeup/lexer.ex b/lib/makeup/lexer.ex
index 39a59bd..f53d7d6 100644
--- a/lib/makeup/lexer.ex
+++ b/lib/makeup/lexer.ex
@@ -88,7 +88,7 @@ defmodule Makeup.Lexer do
   """
   @spec merge(list(T.token())) :: list(T.token())
   def merge([{tag, meta, value1}, {tag, meta, value2} | rest]),
-    do: merge [{tag, meta, value1 <> value2} | rest]
+    do: merge [{tag, meta, [value1, value2]} | rest]
   def merge([token | rest]),
     do: [token | merge(rest)]
   def merge([]),
diff --git a/test/lexer_test.exs b/test/lexer_test.exs
index 8442c4f..bf2e3a8 100644
--- a/test/lexer_test.exs
+++ b/test/lexer_test.exs
@@ -20,6 +20,34 @@ defmodule MakeupTest.LexerTest do
     end
   end
 
+  describe "merge" do
+    test "merges adjacent tokens of the same type and attributes" do
+      tokens = [{:a, %{}, "ab"}, {:a, %{}, "cd"}, {:b, %{}, "ef"}]
+
+      assert [{:a, %{}, value}, {:b, %{}, "ef"}] = Lexer.merge(tokens)
+      assert IO.iodata_to_binary(value) == "abcd"
+    end
+
+    test "does not merge tokens with different attributes" do
+      tokens = [{:a, %{x: 1}, "ab"}, {:a, %{x: 2}, "cd"}]
+
+      assert Lexer.merge(tokens) == tokens
+    end
+
+    test "merges iodata token values" do
+      tokens = [{:a, %{}, ["a", "b"]}, {:a, %{}, "cd"}]
+
+      assert [{:a, %{}, value}] = Lexer.merge(tokens)
+      assert IO.iodata_to_binary(value) == "abcd"
+    end
+
+    test "merging preserves the unlexed string" do
+      tokens = [{:a, %{}, ["a", "b"]}, {:a, %{}, ["c", ["d"]]}, {:b, %{}, "e"}]
+
+      assert tokens |> Lexer.merge() |> Lexer.unlex() == "abcde"
+    end
+  end
+
   describe "split into lines" do
     test "after splitting, token values contain no newline characters" do
       check all tokens <- Gen.tokens() do

From a83085b52b675272eb6307d4d68eb0304fa81e5b Mon Sep 17 00:00:00 2001
From: Javier Garea <javigarea@gmail.com>
Date: Mon, 28 Sep 2026 21:55:42 +0200
Subject: [PATCH 2/2] apply pr suggestion

---
 lib/makeup/lexer.ex | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/makeup/lexer.ex b/lib/makeup/lexer.ex
index f53d7d6..6fee803 100644
--- a/lib/makeup/lexer.ex
+++ b/lib/makeup/lexer.ex
@@ -88,7 +88,7 @@ defmodule Makeup.Lexer do
   """
   @spec merge(list(T.token())) :: list(T.token())
   def merge([{tag, meta, value1}, {tag, meta, value2} | rest]),
-    do: merge [{tag, meta, [value1, value2]} | rest]
+    do: merge [{tag, meta, [value1 | value2]} | rest]
   def merge([token | rest]),
     do: [token | merge(rest)]
   def merge([]),