refactor: replace direct file existence checks with test helpers

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

src/tests/modes/delete_tests.rs

@@ -1,6 +1,6 @@
 #[cfg(test)]
 mod tests {
-    use crate::tests::common::test_helpers::{create_temp_dir, create_empty_temp_file};
+    use crate::tests::common::test_helpers::{create_temp_dir, create_empty_temp_file, assert_file_exists};
 
     #[test]
     fn test_delete_mode_setup() {
@@ -15,6 +15,6 @@ mod tests {
         let test_file = create_empty_temp_file(&temp_dir, "test_delete.txt");
         
         // Verify file exists before deletion test
-        assert!(test_file.exists());
+        assert_file_exists(&test_file);
     }
 }

src/tests/modes/get_tests.rs

@@ -1,6 +1,6 @@
 #[cfg(test)]
 mod tests {
-    use crate::tests::common::test_helpers::{create_temp_dir, test_temp_dir_setup};
+    use crate::tests::common::test_helpers::{create_temp_dir, test_temp_dir_setup, assert_file_not_exists};
 
     #[test]
     fn test_get_mode_basic_setup() {
@@ -14,6 +14,6 @@ mod tests {
         let test_file = temp_dir.path().join("test_get.txt");
         
         // Test path creation
-        assert!(!test_file.exists());
+        assert_file_not_exists(&test_file);
     }
 }

src/tests/modes/info_tests.rs

@@ -1,6 +1,6 @@
 #[cfg(test)]
 mod tests {
-    use crate::tests::common::test_helpers::{create_temp_dir, test_file_creation};
+    use crate::tests::common::test_helpers::{create_temp_dir, test_file_creation, assert_file_not_exists, get_file_size};
     use std::path::PathBuf;
 
     #[test]
@@ -11,8 +11,7 @@ mod tests {
         let file_path = test_file_creation(&dir, "info_test.txt", content);
         
         // Additional verification specific to info mode
-        let metadata = std::fs::metadata(&file_path).expect("Failed to get file metadata");
+        assert!(get_file_size(&file_path) > 0);
-        assert!(metadata.len() > 0);
     }
 
     #[test]
@@ -21,6 +20,6 @@ mod tests {
         let nonexistent_path = PathBuf::from("/nonexistent/file/path.txt");
         
         // Verify the file doesn't exist
-        assert!(!nonexistent_path.exists());
+        assert_file_not_exists(&nonexistent_path);
     }
 }

src/tests/modes/save_tests.rs

@@ -1,6 +1,6 @@
 #[cfg(test)]
 mod tests {
-    use crate::tests::common::test_helpers::{create_temp_dir, create_temp_file_with_content, create_empty_temp_file};
+    use crate::tests::common::test_helpers::{create_temp_dir, create_temp_file_with_content, create_empty_temp_file, assert_file_exists, get_file_size};
 
     #[test]
     fn test_save_mode_basic_functionality() {
@@ -9,7 +9,7 @@ mod tests {
         let file_path = create_temp_file_with_content(&dir, "test_input.txt", "test content for save mode\n");
         
         // Verify file was created
-        assert!(file_path.exists());
+        assert_file_exists(&file_path);
         
         // Note: Actual save mode testing would require integration with the keep database
         // and compression engines, which is complex for unit tests
@@ -22,8 +22,7 @@ mod tests {
         let file_path = create_empty_temp_file(&dir, "empty_test.txt");
         
         // Verify empty file was created
-        assert!(file_path.exists());
+        assert_file_exists(&file_path);
-        let metadata = std::fs::metadata(&file_path).expect("Failed to get file metadata");
+        assert_eq!(get_file_size(&file_path), 0);
-        assert_eq!(metadata.len(), 0);
     }
 }