feat: create common test helpers to reduce duplication across test modules

Co-authored-by: aider (openai/andrew/openrouter/qwen/qwen3-coder) <aider@aider.chat>

src/tests/common/mod.rs

@@ -4,3 +4,5 @@
 pub mod is_binary_tests;
 #[cfg(test)]
 pub mod status_tests;
+#[cfg(test)]
+pub mod test_helpers;

src/tests/common/test_helpers.rs

@@ -0,0 +1,64 @@
+//! Common test utilities and helper functions to reduce duplication in tests
+
+use tempfile::{TempDir, TempPath};
+use std::fs::File;
+use std::io::Write;
+use std::path::PathBuf;
+use rusqlite::Connection;
+use crate::db;
+
+/// Create a temporary directory for testing
+pub fn create_temp_dir() -> TempDir {
+    TempDir::new().expect("Failed to create temporary directory")
+}
+
+/// Create a temporary file with the given content
+pub fn create_temp_file_with_content(dir: &TempDir, filename: &str, content: &str) -> PathBuf {
+    let file_path = dir.path().join(filename);
+    let mut file = File::create(&file_path).expect("Failed to create test file");
+    write!(file, "{}", content).expect("Failed to write to test file");
+    file_path
+}
+
+/// Create an empty temporary file
+pub fn create_empty_temp_file(dir: &TempDir, filename: &str) -> PathBuf {
+    let file_path = dir.path().join(filename);
+    File::create(&file_path).expect("Failed to create empty test file");
+    file_path
+}
+
+/// Helper to test basic temporary directory setup
+pub fn test_temp_dir_setup() {
+    let temp_dir = create_temp_dir();
+    assert!(temp_dir.path().exists());
+}
+
+/// Helper to test file creation and verification
+pub fn test_file_creation(dir: &TempDir, filename: &str, content: &str) -> PathBuf {
+    let file_path = create_temp_file_with_content(dir, filename, content);
+    assert!(file_path.exists());
+    
+    let metadata = std::fs::metadata(&file_path).expect("Failed to get file metadata");
+    assert!(metadata.len() > 0);
+    
+    file_path
+}
+
+/// Create a temporary database for testing
+pub fn create_temp_db() -> (TempDir, Connection, PathBuf) {
+    let temp_dir = create_temp_dir();
+    let db_path = temp_dir.path().join("test.db");
+    let conn = db::open(db_path.clone()).expect("Failed to open database");
+    (temp_dir, conn, db_path)
+}
+
+/// Create a test item in the database
+pub fn create_test_item(conn: &Connection) -> i64 {
+    let item = crate::db::Item {
+        id: None,
+        ts: chrono::Utc::now(),
+        size: Some(100),
+        compression: crate::compression_engine::CompressionType::None.to_string(),
+    };
+    db::insert_item(conn, item).expect("Failed to insert item")
+}