From 73661e925d4fb8952e7b1d60fb753ae2aa4e1699 Mon Sep 17 00:00:00 2001
From: Gabriel Kaszewski <gabrielkaszewski@gmail.com>
Date: Sun, 18 Oct 2026 23:17:15 +0200
Subject: [PATCH] test(ext4): comprehensive edge case and integration tests

---
 .../servers/storage-server/src/tests/ext4.rs  | 99 ++++++++++++++++++-
 1 file changed, 98 insertions(+), 1 deletion(-)

diff --git a/crates/servers/storage-server/src/tests/ext4.rs b/crates/servers/storage-server/src/tests/ext4.rs
index 564a2aa..4284e05 100644
--- a/crates/servers/storage-server/src/tests/ext4.rs
+++ b/crates/servers/storage-server/src/tests/ext4.rs
@@ -460,8 +460,105 @@ fn read_past_eof_returns_zero() {
     let mut fs = Ext4::mount(format_ext4_disk()).unwrap();
     let h = fs.open(b"hello").unwrap();
     let mut buf = [0u8; 32];
-    fs.read(h, &mut buf).unwrap(); // read all 13 bytes
+    fs.read(h, &mut buf).unwrap();
     let read = fs.read(h, &mut buf).unwrap();
     assert_eq!(read, 0);
     fs.close(h);
 }
+
+// --- Review Focus edge cases ---
+
+#[test]
+fn write_allocates_multiple_blocks() {
+    let mut fs = Ext4::mount(format_ext4_disk()).unwrap();
+    let h = fs.create(b"multi").unwrap();
+    let block = [0xABu8; 4096];
+    fs.write(h, &block).unwrap();
+    fs.write(h, &block).unwrap();
+    fs.write(h, &block).unwrap();
+    fs.close(h);
+    let h = fs.open(b"multi").unwrap();
+    assert_eq!(fs.file_size(h), Some(4096 * 3));
+    let mut buf = [0u8; 4096];
+    fs.read(h, &mut buf).unwrap();
+    fs.read(h, &mut buf).unwrap();
+    let n = fs.read(h, &mut buf).unwrap();
+    assert_eq!(n, 4096);
+    assert!(buf.iter().all(|&b| b == 0xAB));
+    fs.close(h);
+}
+
+#[test]
+fn create_multiple_files_in_directory() {
+    let mut fs = Ext4::mount(format_ext4_disk()).unwrap();
+    let h1 = fs.create(b"file_a").unwrap();
+    fs.close(h1);
+    let h2 = fs.create(b"file_b").unwrap();
+    fs.close(h2);
+    let h3 = fs.create(b"file_c").unwrap();
+    fs.close(h3);
+    let mut entries = [DirEntry::empty(); 8];
+    let count = fs.list_dir(b"/", &mut entries).unwrap();
+    assert_eq!(count, 4); // hello + 3 new
+}
+
+#[test]
+fn delete_and_reuse_resources() {
+    let mut fs = Ext4::mount(format_ext4_disk()).unwrap();
+    let h = fs.create(b"ephemeral").unwrap();
+    fs.write(h, b"temp").unwrap();
+    fs.close(h);
+    assert!(fs.delete(b"ephemeral"));
+    let h2 = fs.create(b"recycled").unwrap();
+    fs.write(h2, b"reused").unwrap();
+    fs.close(h2);
+    let h3 = fs.open(b"recycled").unwrap();
+    let mut buf = [0u8; 16];
+    let n = fs.read(h3, &mut buf).unwrap();
+    assert_eq!(&buf[..n], b"reused");
+    fs.close(h3);
+}
+
+#[test]
+fn create_missing_parent_preserves_state() {
+    let mut fs = Ext4::mount(format_ext4_disk()).unwrap();
+    let mut before = [DirEntry::empty(); 8];
+    let count_before = fs.list_dir(b"/", &mut before).unwrap();
+    assert!(fs.create(b"nodir/file.txt").is_none());
+    let mut after = [DirEntry::empty(); 8];
+    let count_after = fs.list_dir(b"/", &mut after).unwrap();
+    assert_eq!(count_before, count_after);
+}
+
+#[test]
+fn two_files_independent_inodes() {
+    let mut fs = Ext4::mount(format_ext4_disk()).unwrap();
+    let h1 = fs.create(b"alpha").unwrap();
+    let h2 = fs.create(b"beta").unwrap();
+    fs.write(h1, b"aaa").unwrap();
+    fs.write(h2, b"bbb").unwrap();
+    fs.close(h1);
+    fs.close(h2);
+    let h1 = fs.open(b"alpha").unwrap();
+    let h2 = fs.open(b"beta").unwrap();
+    let mut buf = [0u8; 16];
+    let n1 = fs.read(h1, &mut buf).unwrap();
+    assert_eq!(&buf[..n1], b"aaa");
+    let n2 = fs.read(h2, &mut buf).unwrap();
+    assert_eq!(&buf[..n2], b"bbb");
+    fs.close(h1);
+    fs.close(h2);
+}
+
+#[test]
+fn delete_nonexistent_returns_false() {
+    let mut fs = Ext4::mount(format_ext4_disk()).unwrap();
+    assert!(!fs.delete(b"ghost"));
+}
+
+#[test]
+fn open_directory_as_file_returns_none() {
+    let mut fs = Ext4::mount(format_ext4_disk()).unwrap();
+    assert!(fs.mkdir(b"adir"));
+    assert!(fs.open(b"adir").is_none());
+}