diff --git a/src/tests/common/is_binary_tests.rs b/src/tests/common/is_binary_tests.rs
index 4a61cf9..f9b82d9 100644
--- a/src/tests/common/is_binary_tests.rs
+++ b/src/tests/common/is_binary_tests.rs
@@ -1 +1,39 @@
-// Common is_binary tests
+#[cfg(test)]
+mod tests {
+    use keep::common::is_binary::calculate_printable_ratio;
+
+    #[test]
+    fn test_calculate_printable_ratio_text() {
+        let text_data = b"Hello, World! This is plain text.\nWith newlines and spaces.";
+        let ratio = calculate_printable_ratio(text_data);
+        
+        // Text data should have high printable ratio
+        assert!(ratio > 0.8);
+    }
+
+    #[test]
+    fn test_calculate_printable_ratio_binary() {
+        let binary_data = b"\x00\x01\x02\x03\x04\x05\x06\x07\x08\x09";
+        let ratio = calculate_printable_ratio(binary_data);
+        
+        // Binary data should have low printable ratio
+        assert!(ratio < 0.5);
+    }
+
+    #[test]
+    fn test_calculate_printable_ratio_mixed() {
+        let mixed_data = b"Text\xff\xfe\xfdMore text\x00\x01";
+        let ratio = calculate_printable_ratio(mixed_data);
+        
+        // Mixed data should have medium printable ratio
+        assert!(ratio > 0.3 && ratio < 0.8);
+    }
+
+    #[test]
+    fn test_calculate_printable_ratio_empty() {
+        let empty_data = b"";
+        // Empty data would cause division by zero, but the function should handle it
+        // Note: This test might need adjustment based on actual implementation
+        let _ = calculate_printable_ratio(empty_data);
+    }
+}
diff --git a/src/tests/common/status_tests.rs b/src/tests/common/status_tests.rs
index dc9bd5b..9f3b3ca 100644
--- a/src/tests/common/status_tests.rs
+++ b/src/tests/common/status_tests.rs
@@ -1 +1,11 @@
-// Common status tests
+#[cfg(test)]
+mod tests {
+    // TODO: Add tests for common status functionality once implemented
+    // This would test functions related to status checking in the common module
+    
+    #[test]
+    fn test_status_placeholder() {
+        // Placeholder test - to be implemented when status functionality is added
+        assert!(true);
+    }
+}
diff --git a/src/tests/compression_engine/program_tests.rs b/src/tests/compression_engine/program_tests.rs
index 38376be..fa9e181 100644
--- a/src/tests/compression_engine/program_tests.rs
+++ b/src/tests/compression_engine/program_tests.rs
@@ -1 +1,30 @@
-// Compression engine program tests
+#[cfg(test)]
+mod tests {
+    use keep::compression_engine::program::CompressionEngineProgram;
+
+    #[test]
+    fn test_compression_engine_program_creation() {
+        let engine = CompressionEngineProgram {
+            program: "gzip".to_string(),
+            compress: vec!["-c".to_string()],
+            decompress: vec!["-d".to_string(), "-c".to_string()],
+            supported: true,
+        };
+        
+        // If the program exists, it should be supported
+        let _ = engine.is_supported();
+    }
+
+    #[test]
+    fn test_compression_engine_program_unsupported() {
+        let engine = CompressionEngineProgram {
+            program: "nonexistent_compression_program".to_string(),
+            compress: vec![],
+            decompress: vec![],
+            supported: false,
+        };
+        
+        // Explicitly unsupported engine should report as such
+        assert!(!engine.is_supported());
+    }
+}
diff --git a/src/tests/db/item_tests.rs b/src/tests/db/item_tests.rs
index 91532c6..6bdedbc 100644
--- a/src/tests/db/item_tests.rs
+++ b/src/tests/db/item_tests.rs
@@ -1 +1,36 @@
-// Database item tests
+#[cfg(test)]
+mod tests {
+    use tempfile::TempDir;
+    use std::path::PathBuf;
+    use keep::db;
+
+    #[test]
+    fn test_database_connection() {
+        // Create a temporary directory for the database
+        let temp_dir = TempDir::new().expect("Failed to create temp directory");
+        let db_path = temp_dir.path().join("test.db");
+        
+        // Try to open the database
+        let result = db::open(db_path);
+        
+        // Should succeed in creating a new database
+        assert!(result.is_ok());
+    }
+
+    #[test]
+    fn test_database_item_queries() {
+        // Create a temporary directory for the database
+        let temp_dir = TempDir::new().expect("Failed to create temp directory");
+        let db_path = temp_dir.path().join("test_items.db");
+        
+        // Open the database
+        let conn = db::open(db_path).expect("Failed to open database");
+        
+        // Try to query all items (should be empty in new DB)
+        let items = db::query_all_items(&conn);
+        assert!(items.is_ok());
+        
+        // Should start with no items
+        assert_eq!(items.unwrap().len(), 0);
+    }
+}
diff --git a/src/tests/db/meta_tests.rs b/src/tests/db/meta_tests.rs
index d604359..7d2c221 100644
--- a/src/tests/db/meta_tests.rs
+++ b/src/tests/db/meta_tests.rs
@@ -1 +1,39 @@
-// Database meta tests
+#[cfg(test)]
+mod tests {
+    use tempfile::TempDir;
+    use keep::db;
+    use keep::db::Meta;
+
+    #[test]
+    fn test_database_meta_operations() {
+        // Create a temporary directory for the database
+        let temp_dir = TempDir::new().expect("Failed to create temp directory");
+        let db_path = temp_dir.path().join("test_meta.db");
+        
+        // Open the database
+        let conn = db::open(db_path).expect("Failed to open database");
+        
+        // Create a test meta
+        let meta = Meta {
+            id: 1,
+            name: "test_key".to_string(),
+            value: "test_value".to_string(),
+        };
+        
+        // Try to insert meta
+        let insert_result = db::query_upsert_meta(&conn, meta.clone());
+        assert!(insert_result.is_ok());
+        
+        // Try to get meta for non-existent item
+        let item = keep::db::Item {
+            id: 999, // Non-existent item
+            ts: chrono::Utc::now(),
+            size: 0,
+            compression: keep::compression_engine::CompressionType::None,
+        };
+        
+        let metas = db::get_item_meta(&conn, &item);
+        assert!(metas.is_ok());
+        assert_eq!(metas.unwrap().len(), 0);
+    }
+}
diff --git a/src/tests/db/tag_tests.rs b/src/tests/db/tag_tests.rs
index c11736c..dcc3e6e 100644
--- a/src/tests/db/tag_tests.rs
+++ b/src/tests/db/tag_tests.rs
@@ -1 +1,47 @@
-// Database tag tests
+#[cfg(test)]
+mod tests {
+    use tempfile::TempDir;
+    use keep::db;
+    use keep::db::Tag;
+
+    #[test]
+    fn test_database_tag_operations() {
+        // Create a temporary directory for the database
+        let temp_dir = TempDir::new().expect("Failed to create temp directory");
+        let db_path = temp_dir.path().join("test_tags.db");
+        
+        // Open the database
+        let conn = db::open(db_path).expect("Failed to open database");
+        
+        // Create a test tag
+        let tag = Tag {
+            id: 1,
+            name: "test_tag".to_string(),
+        };
+        
+        // Try to insert tag
+        let insert_result = db::insert_tag(&conn, tag.clone());
+        assert!(insert_result.is_ok());
+    }
+
+    #[test]
+    fn test_database_item_tag_operations() {
+        // Create a temporary directory for the database
+        let temp_dir = TempDir::new().expect("Failed to create temp directory");
+        let db_path = temp_dir.path().join("test_item_tags.db");
+        
+        // Open the database
+        let conn = db::open(db_path).expect("Failed to open database");
+        
+        // Try to delete tags for non-existent item
+        let item = keep::db::Item {
+            id: 999, // Non-existent item
+            ts: chrono::Utc::now(),
+            size: 0,
+            compression: keep::compression_engine::CompressionType::None,
+        };
+        
+        let delete_result = db::delete_item_tags(&conn, item);
+        assert!(delete_result.is_ok());
+    }
+}
diff --git a/src/tests/meta_plugin/digest_tests.rs b/src/tests/meta_plugin/digest_tests.rs
index 2b8e23f..f0b2803 100644
--- a/src/tests/meta_plugin/digest_tests.rs
+++ b/src/tests/meta_plugin/digest_tests.rs
@@ -1 +1,47 @@
-// Meta plugin digest tests
+#[cfg(test)]
+mod tests {
+    use keep::meta_plugin::digest::*;
+    use keep::meta_plugin::MetaPlugin;
+    use std::io::Write;
+
+    #[test]
+    fn test_digest_sha256_meta_plugin() {
+        let mut plugin = DigestSha256MetaPlugin::new("test_digest".to_string());
+        
+        assert_eq!(plugin.meta_name(), "test_digest");
+        assert!(plugin.is_internal());
+        
+        // Creating a writer should work
+        let writer_result = plugin.create();
+        assert!(writer_result.is_ok());
+        
+        // Writing some data
+        let mut writer = writer_result.unwrap();
+        let write_result = writer.write(b"test data");
+        assert!(write_result.is_ok());
+    }
+
+    #[test]
+    fn test_read_time_meta_plugin() {
+        let mut plugin = ReadTimeMetaPlugin::new("read_time_test".to_string());
+        
+        assert_eq!(plugin.meta_name(), "read_time_test");
+        assert!(plugin.is_internal());
+        
+        // Creating a writer should work
+        let writer_result = plugin.create();
+        assert!(writer_result.is_ok());
+    }
+
+    #[test]
+    fn test_read_rate_meta_plugin() {
+        let mut plugin = ReadRateMetaPlugin::new("read_rate_test".to_string());
+        
+        assert_eq!(plugin.meta_name(), "read_rate_test");
+        assert!(plugin.is_internal());
+        
+        // Creating a writer should work
+        let writer_result = plugin.create();
+        assert!(writer_result.is_ok());
+    }
+}
diff --git a/src/tests/meta_plugin/program_tests.rs b/src/tests/meta_plugin/program_tests.rs
index 2f8e061..525a457 100644
--- a/src/tests/meta_plugin/program_tests.rs
+++ b/src/tests/meta_plugin/program_tests.rs
@@ -1 +1,50 @@
-// Meta plugin program tests
+#[cfg(test)]
+mod tests {
+    use keep::meta_plugin::program::MetaPluginProgram;
+    use keep::meta_plugin::MetaPlugin;
+    use std::io::Write;
+
+    #[test]
+    fn test_meta_plugin_program_creation() {
+        let plugin = MetaPluginProgram::new(
+            "echo".to_string(),
+            vec!["test".to_string()],
+            "test_plugin".to_string(),
+            false,
+        );
+        
+        assert_eq!(plugin.meta_name(), "test_plugin");
+        // If echo is available, it should be supported
+        // We don't assert on is_supported() as it depends on system availability
+    }
+
+    #[test]
+    fn test_meta_plugin_program_create_writer() {
+        let plugin = MetaPluginProgram::new(
+            "cat".to_string(),
+            vec![].to_vec(),
+            "cat_plugin".to_string(),
+            false,
+        );
+        
+        // Creating a writer should work for valid programs
+        let result = plugin.create();
+        // We don't assert success as it depends on system availability
+        // but we ensure it doesn't panic
+        let _ = result;
+    }
+
+    #[test]
+    fn test_meta_plugin_program_unsupported() {
+        let plugin = MetaPluginProgram::new(
+            "nonexistent_program_xyz".to_string(),
+            vec![].to_vec(),
+            "bad_plugin".to_string(),
+            false,
+        );
+        
+        // An unsupported plugin should report as such
+        // Note: This might still be supported if the program exists
+        let _ = plugin.is_supported();
+    }
+}
diff --git a/src/tests/meta_plugin/system_tests.rs b/src/tests/meta_plugin/system_tests.rs
index 032a92d..24f4d45 100644
--- a/src/tests/meta_plugin/system_tests.rs
+++ b/src/tests/meta_plugin/system_tests.rs
@@ -1 +1,57 @@
-// Meta plugin system tests
+#[cfg(test)]
+mod tests {
+    use keep::meta_plugin::system::*;
+    use keep::meta_plugin::MetaPlugin;
+
+    #[test]
+    fn test_cwd_meta_plugin() {
+        let mut plugin = CwdMetaPlugin::new();
+        
+        assert_eq!(plugin.meta_name(), "cwd");
+        assert!(plugin.is_internal());
+        
+        // Creating a writer should work
+        let writer_result = plugin.create();
+        assert!(writer_result.is_ok());
+        
+        // Finalize should return current working directory
+        let result = plugin.finalize();
+        assert!(result.is_ok());
+    }
+
+    #[test]
+    fn test_binary_meta_plugin() {
+        let mut plugin = BinaryMetaPlugin::new();
+        
+        assert_eq!(plugin.meta_name(), "binary");
+        assert!(plugin.is_internal());
+        
+        // Creating a writer should work
+        let writer_result = plugin.create();
+        assert!(writer_result.is_ok());
+    }
+
+    #[test]
+    fn test_uid_meta_plugin() {
+        let mut plugin = UidMetaPlugin::new();
+        
+        assert_eq!(plugin.meta_name(), "uid");
+        assert!(plugin.is_internal());
+        
+        // Creating a writer should work
+        let writer_result = plugin.create();
+        assert!(writer_result.is_ok());
+    }
+
+    #[test]
+    fn test_user_meta_plugin() {
+        let mut plugin = UserMetaPlugin::new();
+        
+        assert_eq!(plugin.meta_name(), "user");
+        assert!(plugin.is_internal());
+        
+        // Creating a writer should work
+        let writer_result = plugin.create();
+        assert!(writer_result.is_ok());
+    }
+}
diff --git a/src/tests/modes/delete_tests.rs b/src/tests/modes/delete_tests.rs
index 66a3051..242e6ff 100644
--- a/src/tests/modes/delete_tests.rs
+++ b/src/tests/modes/delete_tests.rs
@@ -1 +1,29 @@
-// Modes delete tests
+#[cfg(test)]
+mod tests {
+    use tempfile::TempDir;
+    use std::fs::File;
+
+    #[test]
+    fn test_delete_mode_setup() {
+        // Create a temporary directory for testing
+        let temp_dir = TempDir::new().expect("Failed to create temp directory");
+        
+        // Test that we can work with temporary directories
+        assert!(temp_dir.path().exists());
+    }
+
+    #[test]
+    fn test_delete_mode_file_creation_and_deletion() {
+        // Create a temporary directory for testing
+        let temp_dir = TempDir::new().expect("Failed to create temp directory");
+        let test_file = temp_dir.path().join("test_delete.txt");
+        
+        // Create a test file
+        {
+            let _file = File::create(&test_file).expect("Failed to create test file");
+        }
+        
+        // Verify file exists before deletion test
+        assert!(test_file.exists());
+    }
+}
diff --git a/src/tests/modes/diff_tests.rs b/src/tests/modes/diff_tests.rs
index 952caee..9f7ee93 100644
--- a/src/tests/modes/diff_tests.rs
+++ b/src/tests/modes/diff_tests.rs
@@ -1 +1,13 @@
-// Modes diff tests
+#[cfg(test)]
+mod tests {
+    use tempfile::TempDir;
+
+    #[test]
+    fn test_diff_mode_basic_setup() {
+        // Create a temporary directory for testing
+        let temp_dir = TempDir::new().expect("Failed to create temp directory");
+        
+        // Test that we can work with temporary directories
+        assert!(temp_dir.path().exists());
+    }
+}
diff --git a/src/tests/modes/get_tests.rs b/src/tests/modes/get_tests.rs
index afd67f9..a972d13 100644
--- a/src/tests/modes/get_tests.rs
+++ b/src/tests/modes/get_tests.rs
@@ -1 +1,23 @@
-// Modes get tests
+#[cfg(test)]
+mod tests {
+    use tempfile::TempDir;
+
+    #[test]
+    fn test_get_mode_basic_setup() {
+        // Create a temporary directory for testing
+        let temp_dir = TempDir::new().expect("Failed to create temp directory");
+        
+        // Test that we can work with temporary directories
+        assert!(temp_dir.path().exists());
+    }
+
+    #[test]
+    fn test_get_mode_path_operations() {
+        // Create a temporary directory for testing
+        let temp_dir = TempDir::new().expect("Failed to create temp directory");
+        let test_file = temp_dir.path().join("test_get.txt");
+        
+        // Test path creation
+        assert!(!test_file.exists());
+    }
+}
diff --git a/src/tests/modes/info_tests.rs b/src/tests/modes/info_tests.rs
index 28a3c44..16cfc8e 100644
--- a/src/tests/modes/info_tests.rs
+++ b/src/tests/modes/info_tests.rs
@@ -1 +1,35 @@
-// Modes info tests
+#[cfg(test)]
+mod tests {
+    use tempfile::TempDir;
+    use std::fs::File;
+    use std::io::Write;
+
+    #[test]
+    fn test_info_mode_file_operations() {
+        // Create a temporary directory for testing
+        let dir = TempDir::new().expect("Failed to create temp directory");
+        let file_path = dir.path().join("info_test.txt");
+        
+        // Create a test file
+        {
+            let mut file = File::create(&file_path).expect("Failed to create test file");
+            writeln!(file, "This is a test file for info mode").expect("Failed to write to test file");
+            writeln!(file, "With multiple lines").expect("Failed to write second line");
+        }
+        
+        // Verify file exists and has content
+        assert!(file_path.exists());
+        
+        let metadata = std::fs::metadata(&file_path).expect("Failed to get file metadata");
+        assert!(metadata.len() > 0);
+    }
+
+    #[test]
+    fn test_info_mode_nonexistent_file() {
+        // Create a path to a file that doesn't exist
+        let nonexistent_path = PathBuf::from("/nonexistent/file/path.txt");
+        
+        // Verify the file doesn't exist
+        assert!(!nonexistent_path.exists());
+    }
+}
diff --git a/src/tests/modes/list_tests.rs b/src/tests/modes/list_tests.rs
index 855bfe3..1735687 100644
--- a/src/tests/modes/list_tests.rs
+++ b/src/tests/modes/list_tests.rs
@@ -1 +1,26 @@
-// Modes list tests
+#[cfg(test)]
+mod tests {
+    use tempfile::TempDir;
+
+    #[test]
+    fn test_list_mode_basic_setup() {
+        // Create a temporary directory for testing
+        let temp_dir = TempDir::new().expect("Failed to create temp directory");
+        
+        // Test that we can work with temporary directories
+        assert!(temp_dir.path().exists());
+    }
+
+    #[test]
+    fn test_list_mode_directory_operations() {
+        // Create a temporary directory for testing
+        let temp_dir = TempDir::new().expect("Failed to create temp directory");
+        
+        // Test reading directory contents (should be empty)
+        let entries: Vec<_> = std::fs::read_dir(temp_dir.path())
+            .expect("Failed to read directory")
+            .collect();
+        
+        assert_eq!(entries.len(), 0);
+    }
+}
diff --git a/src/tests/modes/save_tests.rs b/src/tests/modes/save_tests.rs
index 666d1aa..bb918eb 100644
--- a/src/tests/modes/save_tests.rs
+++ b/src/tests/modes/save_tests.rs
@@ -1 +1,43 @@
-// Modes save tests
+#[cfg(test)]
+mod tests {
+    use tempfile::tempdir;
+    use std::fs::File;
+    use std::io::Write;
+
+    #[test]
+    fn test_save_mode_basic_functionality() {
+        // Create a temporary directory for testing
+        let dir = tempdir().expect("Failed to create temporary directory");
+        let file_path = dir.path().join("test_input.txt");
+        
+        // Create a test file
+        {
+            let mut file = File::create(&file_path).expect("Failed to create test file");
+            writeln!(file, "test content for save mode").expect("Failed to write to test file");
+        }
+        
+        // Verify file was created
+        assert!(file_path.exists());
+        
+        // Note: Actual save mode testing would require integration with the keep database
+        // and compression engines, which is complex for unit tests
+    }
+
+    #[test]
+    fn test_save_mode_empty_file() {
+        // Create a temporary directory for testing
+        let dir = tempdir().expect("Failed to create temporary directory");
+        let file_path = dir.path().join("empty_test.txt");
+        
+        // Create an empty test file
+        {
+            let file = File::create(&file_path).expect("Failed to create empty test file");
+            // File is automatically closed when it goes out of scope
+        }
+        
+        // Verify empty file was created
+        assert!(file_path.exists());
+        let metadata = std::fs::metadata(&file_path).expect("Failed to get file metadata");
+        assert_eq!(metadata.len(), 0);
+    }
+}
diff --git a/src/tests/modes/status_tests.rs b/src/tests/modes/status_tests.rs
index 20328e3..87d9530 100644
--- a/src/tests/modes/status_tests.rs
+++ b/src/tests/modes/status_tests.rs
@@ -1 +1,13 @@
-// Modes status tests
+#[cfg(test)]
+mod tests {
+    use tempfile::TempDir;
+
+    #[test]
+    fn test_status_mode_basic_setup() {
+        // Create a temporary directory for testing
+        let temp_dir = TempDir::new().expect("Failed to create temp directory");
+        
+        // Test that we can work with temporary directories
+        assert!(temp_dir.path().exists());
+    }
+}
diff --git a/src/tests/modes/update_tests.rs b/src/tests/modes/update_tests.rs
index 3bfceda..cf40285 100644
--- a/src/tests/modes/update_tests.rs
+++ b/src/tests/modes/update_tests.rs
@@ -1 +1,13 @@
-// Modes update tests
+#[cfg(test)]
+mod tests {
+    use tempfile::TempDir;
+
+    #[test]
+    fn test_update_mode_basic_setup() {
+        // Create a temporary directory for testing
+        let temp_dir = TempDir::new().expect("Failed to create temp directory");
+        
+        // Test that we can work with temporary directories
+        assert!(temp_dir.path().exists());
+    }
+}
diff --git a/src/tests/server/api_tests.rs b/src/tests/server/api_tests.rs
index 59a14eb..7722f5f 100644
--- a/src/tests/server/api_tests.rs
+++ b/src/tests/server/api_tests.rs
@@ -1 +1,14 @@
-// Server API tests
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_api_basic_setup() {
+        // Placeholder for API tests
+        assert!(true);
+    }
+
+    #[test]
+    fn test_api_endpoints() {
+        // Placeholder for testing server API endpoints
+        assert!(true);
+    }
+}
diff --git a/src/tests/server/auth_tests.rs b/src/tests/server/auth_tests.rs
index 1faefcc..32b064d 100644
--- a/src/tests/server/auth_tests.rs
+++ b/src/tests/server/auth_tests.rs
@@ -1 +1,80 @@
-// Server authentication tests
+#[cfg(test)]
+mod tests {
+    use axum::http::{HeaderMap, HeaderValue};
+    use keep::modes::server::common::check_auth;
+
+    #[test]
+    fn test_auth_with_no_password_required() {
+        let headers = HeaderMap::new();
+        let password = None;
+        
+        // When no password is required, auth should pass
+        assert!(check_auth(&headers, &password));
+    }
+
+    #[test]
+    fn test_auth_with_bearer_token() {
+        let mut headers = HeaderMap::new();
+        headers.insert("authorization", HeaderValue::from_static("Bearer secret123"));
+        
+        let password = Some("secret123".to_string());
+        
+        // Valid bearer token should pass
+        assert!(check_auth(&headers, &password));
+    }
+
+    #[test]
+    fn test_auth_with_invalid_bearer_token() {
+        let mut headers = HeaderMap::new();
+        headers.insert("authorization", HeaderValue::from_static("Bearer wrongtoken"));
+        
+        let password = Some("secret123".to_string());
+        
+        // Invalid bearer token should fail
+        assert!(!check_auth(&headers, &password));
+    }
+
+    #[test]
+    fn test_auth_with_basic_auth() {
+        let mut headers = HeaderMap::new();
+        // Basic auth for "keep:secret123" base64 encoded
+        headers.insert("authorization", HeaderValue::from_static("Basic a2VlcDpzZWNyZXQxMjM="));
+        
+        let password = Some("secret123".to_string());
+        
+        // Valid basic auth should pass
+        assert!(check_auth(&headers, &password));
+    }
+
+    #[test]
+    fn test_auth_with_invalid_basic_auth() {
+        let mut headers = HeaderMap::new();
+        // Basic auth for "keep:wrongpass" base64 encoded
+        headers.insert("authorization", HeaderValue::from_static("Basic a2VlcDp3cm9uZ3Bhc3M="));
+        
+        let password = Some("secret123".to_string());
+        
+        // Invalid basic auth should fail
+        assert!(!check_auth(&headers, &password));
+    }
+
+    #[test]
+    fn test_auth_with_missing_auth_header() {
+        let headers = HeaderMap::new();
+        let password = Some("secret123".to_string());
+        
+        // Missing auth header should fail when password is required
+        assert!(!check_auth(&headers, &password));
+    }
+
+    #[test]
+    fn test_auth_with_malformed_auth_header() {
+        let mut headers = HeaderMap::new();
+        headers.insert("authorization", HeaderValue::from_static("Invalid header"));
+        
+        let password = Some("secret123".to_string());
+        
+        // Malformed auth header should fail
+        assert!(!check_auth(&headers, &password));
+    }
+}