From 140f72d46438a5bf7915a383f6a62d54e189292b Mon Sep 17 00:00:00 2001
From: "Panagiotis \"Ivory\" Vasilopoulos" <git@n0toose.net>
Date: Thu, 21 Nov 2024 15:20:27 +0100
Subject: [PATCH] test: add fs-related helper functions

This should help us keep up with the increasing complexity of the tests
(including for features currently being developed). verify_file_equals
is not particularly useful right now, but I intend on using it more
intensively for the UhyveFileMap feature much more extensively.
---
 tests/common.rs  |  9 +++++++++
 tests/fs-test.rs | 24 +++++++++++++-----------
 tests/serial.rs  | 15 ++++-----------
 3 files changed, 26 insertions(+), 22 deletions(-)

diff --git a/tests/common.rs b/tests/common.rs
index edabb7fe..20638361 100644
--- a/tests/common.rs
+++ b/tests/common.rs
@@ -1,5 +1,6 @@
 use std::{
 	env,
+	fs::remove_file,
 	path::{Path, PathBuf},
 	process::Command,
 };
@@ -57,3 +58,11 @@ pub fn run_simple_vm(kernel_path: PathBuf) -> VmResult {
 	};
 	UhyveVm::new(kernel_path, params).unwrap().run(None)
 }
+
+/// Removes a file if it already exists on the host OS.
+pub fn remove_file_if_exists(path: &PathBuf) {
+	if path.exists() {
+		println!("Removing existing directory {}", path.display());
+		remove_file(path).unwrap_or_else(|_| panic!("Can't remove {}", path.display()));
+	}
+}
diff --git a/tests/fs-test.rs b/tests/fs-test.rs
index c1c29b25..15119918 100644
--- a/tests/fs-test.rs
+++ b/tests/fs-test.rs
@@ -1,24 +1,26 @@
 mod common;
 
 use std::{
-	fs::{read, remove_file},
+	fs::{read_to_string, remove_file},
 	path::PathBuf,
 };
 
-use common::{build_hermit_bin, run_simple_vm};
+use common::{build_hermit_bin, remove_file_if_exists, run_simple_vm};
+
+/// Verifies successful file creation on the host OS and its contents.
+pub fn verify_file_equals(testfile: &PathBuf, contents: &str) {
+	assert!(testfile.exists());
+	let file_content = read_to_string(testfile).unwrap();
+	assert_eq!(file_content, contents.to_string());
+}
 
 #[test]
 fn new_file_test() {
-	let testfile = PathBuf::from("foo.txt");
-	if testfile.exists() {
-		println!("Removing existing file {}", testfile.display());
-		remove_file(&testfile).unwrap_or_else(|_| panic!("Can't remove {}", testfile.display()));
-	}
+	let output_path = PathBuf::from("foo.txt");
+	remove_file_if_exists(&output_path);
 	let bin_path = build_hermit_bin("create_file");
 	run_simple_vm(bin_path);
 
-	assert!(testfile.exists());
-	let file_content = read("foo.txt").unwrap();
-	assert_eq!(file_content, "Hello, world!".as_bytes());
-	remove_file(&testfile).unwrap_or_else(|_| panic!("Can't remove {}", testfile.display()));
+	verify_file_equals(&output_path, "Hello, world!");
+	remove_file(&output_path).unwrap_or_else(|_| panic!("Can't remove {}", output_path.display()));
 }
diff --git a/tests/serial.rs b/tests/serial.rs
index 0976a833..4017f471 100644
--- a/tests/serial.rs
+++ b/tests/serial.rs
@@ -1,12 +1,9 @@
 mod common;
 
-use std::{
-	fs::{read_to_string, remove_file},
-	path::PathBuf,
-};
+use std::{fs::read_to_string, path::PathBuf};
 
 use byte_unit::{Byte, Unit};
-use common::{build_hermit_bin, run_simple_vm};
+use common::{build_hermit_bin, remove_file_if_exists, run_simple_vm};
 use uhyvelib::{
 	params::{Output, Params},
 	vm::UhyveVm,
@@ -30,11 +27,7 @@ fn serial_file_output_test() {
 	env_logger::try_init().ok();
 	let bin_path = build_hermit_bin("serial");
 	let output_path: PathBuf = "testserialout.txt".into();
-	if output_path.exists() {
-		println!("Removing existing file {}", output_path.display());
-		remove_file(&output_path)
-			.unwrap_or_else(|_| panic!("Can't remove {}", output_path.display()));
-	}
+	remove_file_if_exists(&output_path);
 
 	println!("Launching kernel {}", bin_path.display());
 	let params = Params {
@@ -55,5 +48,5 @@ fn serial_file_output_test() {
 	let file_content = read_to_string(&output_path).unwrap();
 	assert!(file_content.contains("Hello from serial!\nABCD\n1234ASDF!@#$\n"));
 
-	remove_file(&output_path).unwrap_or_else(|_| panic!("Can't remove {}", output_path.display()));
+	remove_file_if_exists(&output_path);
 }