From 0680a282e0bf41b6bfc34cc9a3e4ae1906df3b5d Mon Sep 17 00:00:00 2001
From: Lev Demidov <lev.demidov@contrastsecurity.com>
Date: Tue, 8 Jul 2025 18:34:45 -0400
Subject: [PATCH 1/2] Adds test (currently failing) to show that a UTF-8 file
 with BOM is not parsed properly when read using FileSourceFile

---
 tests/testsuite/file-ext-with-bom.json |  4 ++++
 tests/testsuite/file.rs                | 12 ++++++++++++
 2 files changed, 16 insertions(+)
 create mode 100644 tests/testsuite/file-ext-with-bom.json

diff --git a/tests/testsuite/file-ext-with-bom.json b/tests/testsuite/file-ext-with-bom.json
new file mode 100644
index 00000000..03e3c7c0
--- /dev/null
+++ b/tests/testsuite/file-ext-with-bom.json
@@ -0,0 +1,4 @@
+{
+    "debug": true,
+    "production": false
+}
diff --git a/tests/testsuite/file.rs b/tests/testsuite/file.rs
index 33077852..669cba59 100644
--- a/tests/testsuite/file.rs
+++ b/tests/testsuite/file.rs
@@ -67,6 +67,18 @@ fn test_file_ext() {
     assert_eq!(c.get("production").ok(), Some(false));
 }
 
+#[test]
+#[cfg(feature = "json")]
+fn test_file_ext_with_utf8_bom() {
+    let c = Config::builder()
+        .add_source(File::with_name("tests/testsuite/file-ext-with-bom.json"))
+        .build()
+        .unwrap();
+
+    assert_eq!(c.get("debug").ok(), Some(true));
+    assert_eq!(c.get("production").ok(), Some(false));
+}
+
 #[test]
 #[cfg(feature = "json")]
 fn test_file_second_ext() {

From 588bd664c86bb2a6588a221c0bd9dd02a00605f3 Mon Sep 17 00:00:00 2001
From: Lev Demidov <lev.demidov@contrastsecurity.com>
Date: Tue, 8 Jul 2025 18:48:33 -0400
Subject: [PATCH 2/2] Skip the UTF-8 BOM bytes when reading the file contents
 in FileSource.

---
 src/file/source/file.rs | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/src/file/source/file.rs b/src/file/source/file.rs
index 0e0687c2..bf30c119 100644
--- a/src/file/source/file.rs
+++ b/src/file/source/file.rs
@@ -115,7 +115,17 @@ where
             .unwrap_or_else(|| filename.clone());
 
         // Read contents from file
-        let text = fs::read_to_string(filename)?;
+        let buf = fs::read(filename)?;
+
+        // If it exists, skip the UTF-8 BOM byte sequence: EF BB BF
+        let buf = if buf.len() >= 3 && &buf[0..3] == b"\xef\xbb\xbf" {
+            &buf[3..]
+        } else {
+            &buf
+        };
+
+        let c = String::from_utf8_lossy(buf);
+        let text = c.into_owned();
 
         Ok(FileSourceResult {
             uri: Some(uri.to_string_lossy().into_owned()),