Improve the generation of unique filenames used in unit tests

Author: FastAlien

src/auth_file_watcher.test.rs

@@ -21,7 +21,7 @@ fn when_monitored_file_does_not_exist_then_new_does_not_return_error() {
 
 #[test]
 fn when_new_line_is_added_to_file_then_update_callback_is_called() {
-    let mut file = TestFile::new("auth-monitor-test");
+    let mut file = TestFile::with_unique_name();
     let mut auth_file_watcher =
         AuthFileWatcher::new(&file.filepath).expect("Error creating AuthFileWatcher");
     expect_no_update_callback_call(&mut auth_file_watcher);
@@ -47,7 +47,7 @@ fn expect_update_callback_is_called_when_file_is_modified(
 
 #[test]
 fn when_more_than_one_line_is_added_then_update_callback_is_called_for_each_line() {
-    let mut file = TestFile::new("auth-monitor-test");
+    let mut file = TestFile::with_unique_name();
     let mut auth_file_watcher =
         AuthFileWatcher::new(&file.filepath).expect("Error creating AuthFileWatcher");
     expect_no_update_callback_call(&mut auth_file_watcher);
@@ -73,7 +73,7 @@ fn when_more_than_one_line_is_added_then_update_callback_is_called_for_each_line
 
 #[test]
 fn when_new_file_was_created_after_old_was_deleted_then_changes_in_new_file_are_monitored() {
-    let mut file = TestFile::new("auth-monitor-test");
+    let mut file = TestFile::with_unique_name();
     let mut auth_file_watcher =
         AuthFileWatcher::new(&file.filepath).expect("Error creating AuthFileWatcher");
     expect_no_update_callback_call(&mut auth_file_watcher);
@@ -95,7 +95,7 @@ fn expect_no_update_callback_call(auth_file_watcher: &mut AuthFileWatcher) {
 
 #[test]
 fn when_new_file_has_been_created_after_old_was_renamed_then_changes_in_new_file_are_monitored() {
-    let mut file = TestFile::new("auth-monitor-test");
+    let mut file = TestFile::with_unique_name();
     let mut auth_file_watcher =
         AuthFileWatcher::new(&file.filepath).expect("Error creating AuthFileWatcher");
     expect_no_update_callback_call(&mut auth_file_watcher);
@@ -111,7 +111,7 @@ fn when_new_file_has_been_created_after_old_was_renamed_then_changes_in_new_file
 
 #[test]
 fn when_monitored_file_has_been_truncated_then_changes_are_still_monitored() {
-    let mut file = TestFile::new("auth-monitor-test");
+    let mut file = TestFile::with_unique_name();
     let mut auth_file_watcher =
         AuthFileWatcher::new(&file.filepath).expect("Error creating AuthFileWatcher");
     expect_no_update_callback_call(&mut auth_file_watcher);

src/auth_monitor.test.rs

@@ -21,7 +21,7 @@ const OTHER_TEST_MESSAGES: [&str; 4] = [
 #[test]
 pub fn when_max_failed_attempts_limit_is_reached_then_update_callback_is_called() {
     for max_failed_attempts in 2..10 {
-        let mut file = TestFile::new("auth-monitor");
+        let mut file = TestFile::with_unique_name();
         let mut auth_monitor = AuthMonitor::new(AuthMonitorParams {
             filepath: file.filepath.clone(),
             options: AuthMonitorOptions {
@@ -101,7 +101,7 @@ pub fn when_reset_after_seconds_passed_then_failed_attempts_count_is_reset() {
         max_failed_attempts: 3,
         reset_after_seconds: 5,
     };
-    let mut file = TestFile::new("auth-monitor");
+    let mut file = TestFile::with_unique_name();
     let mut auth_monitor = AuthMonitor::new(AuthMonitorParams {
         filepath: file.filepath.clone(),
         options,
@@ -135,7 +135,7 @@ pub fn when_reset_after_seconds_passed_then_failed_attempts_count_is_reset() {
 pub fn when_max_failed_attempts_limit_is_reached_before_update_is_called_then_update_callback_is_called(
 ) {
     for max_failed_attempts in 2..10 {
-        let mut file = TestFile::new("auth-monitor");
+        let mut file = TestFile::with_unique_name();
         let mut auth_monitor = AuthMonitor::new(AuthMonitorParams {
             filepath: file.filepath.clone(),
             options: AuthMonitorOptions {

src/test_utils/test_file.rs

@@ -2,6 +2,7 @@ use std::env::temp_dir;
 use std::fs::{remove_file, rename, File};
 use std::io::Write;
 use std::path::Path;
+use std::sync::atomic::{AtomicUsize, Ordering};
 
 use chrono::Local;
 
@@ -11,14 +12,27 @@ pub struct TestFile {
 }
 
 impl TestFile {
-    pub fn new(prefix: &str) -> TestFile {
-        let filename = format!("{}-{}.log", prefix, Local::now().timestamp_micros());
+    pub fn with_unique_name() -> TestFile {
+        let filename = format!(
+            "auth-monitor-test-{}-{}.log",
+            Self::next_id(),
+            Local::now().timestamp_micros()
+        );
         let filepath_buffer = temp_dir().join(filename);
         let filepath = filepath_buffer.to_str().expect("Error creating filepath");
-        println!("Creating test file: {}", filepath);
+        return Self::new(filepath);
+    }
+
+    fn next_id() -> usize {
+        static ID: AtomicUsize = AtomicUsize::new(1);
+        return ID.fetch_add(1, Ordering::Relaxed);
+    }
+
+    pub fn new(path: &str) -> TestFile {
+        println!("Creating test file: {}", path);
         return TestFile {
-            filepath: String::from(filepath),
-            file: File::create(filepath).expect("Error creating test file"),
+            filepath: String::from(path),
+            file: File::create(path).expect("Error creating test file"),
         };
     }