From 9a7092e8f03f370adea7c8027a809d8430867509 Mon Sep 17 00:00:00 2001
From: Lukasz Samson <lukaszsamson@gmail.com>
Date: Tue, 21 Apr 2026 14:41:29 +0200
Subject: [PATCH] Enrich EEx.SyntaxError with error metadata

Fixes #15296
---
 lib/eex/lib/eex/compiler.ex | 18 ++++++++++++++++--
 lib/eex/test/eex_test.exs   | 12 ++++++++++++
 2 files changed, 28 insertions(+), 2 deletions(-)

diff --git a/lib/eex/lib/eex/compiler.ex b/lib/eex/lib/eex/compiler.ex
index 56d0a413971..0511023b45e 100644
--- a/lib/eex/lib/eex/compiler.ex
+++ b/lib/eex/lib/eex/compiler.ex
@@ -347,7 +347,7 @@ defmodule EEx.Compiler do
         state.parser_options
 
     expr = Code.string_to_quoted!(chars, options)
-    buffer = state.engine.handle_expr(buffer, IO.chardata_to_string(mark), expr)
+    buffer = handle_expr(buffer, mark, expr, meta, state)
     generate_buffer(rest, buffer, scope, state)
   end
 
@@ -376,7 +376,7 @@ defmodule EEx.Compiler do
       IO.warn(message, file: state.file, line: meta.line, column: meta.column)
     end
 
-    buffer = state.engine.handle_expr(buffer, IO.chardata_to_string(mark), contents)
+    buffer = handle_expr(buffer, mark, contents, meta, state)
     generate_buffer(rest, buffer, scope, state)
   end
 
@@ -513,6 +513,20 @@ defmodule EEx.Compiler do
       column: meta.column
   end
 
+  defp handle_expr(buffer, mark, expr, meta, state) do
+    state.engine.handle_expr(buffer, IO.chardata_to_string(mark), expr)
+  rescue
+    e in EEx.SyntaxError ->
+      reraise %{
+                e
+                | file: e.file || state.file,
+                  line: e.line || meta.line,
+                  column: e.column || meta.column,
+                  snippet: e.snippet || code_snippet(state.source, state.indentation, meta)
+              },
+              __STACKTRACE__
+  end
+
   defp code_snippet(source, indentation, meta) do
     line_start = max(meta.line - 3, 1)
     line_end = meta.line
diff --git a/lib/eex/test/eex_test.exs b/lib/eex/test/eex_test.exs
index 5214b3afc64..27c4e9abbcb 100644
--- a/lib/eex/test/eex_test.exs
+++ b/lib/eex/test/eex_test.exs
@@ -575,6 +575,18 @@ defmodule EExTest do
         EEx.compile_string("foo <%= bar", file: "my_file.eex")
       end
     end
+
+    test "unsupported marker error carries template location metadata" do
+      error =
+        assert_raise EEx.SyntaxError, fn ->
+          EEx.compile_string("<%/ true %>", file: "sample.eex", line: 7)
+        end
+
+      assert error.file == "sample.eex"
+      assert error.line == 7
+      assert error.column == 1
+      assert Exception.message(error) =~ "sample.eex:7:1:"
+    end
   end
 
   describe "warnings" do