From b00b13182d013ebd5d3296b888e7929a927b42ad Mon Sep 17 00:00:00 2001
From: Evan Leis <evan.explodes@gmail.com>
Date: Sat, 11 Apr 2026 19:28:51 +0800
Subject: [PATCH] Fix parallel tests.

Running tests in parallel (default behavior) means that multiple tests will work with the /tmp/db file.
This results in unpredicable test results.
Using self-deleting tempdirs, we can work around this.
Note that the WAL is automatically placed in the same directory as the db with a fixed name, so this
temp directory actually creates a unique, safe place for the WAL file as well.
---
 Cargo.toml   |  3 +++
 src/btree.rs | 47 +++++++++++++++++++++--------------------------
 2 files changed, 24 insertions(+), 26 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index 882d4da..612280d 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -18,3 +18,6 @@ path = "src/lib.rs"
 byteorder = "1.3.4"
 uuid = { version = "0.8", features = ["serde", "v4"] }
 memmap = "0.7.0"
+
+[dev-dependencies]
+tempfile = { version = "3" }
diff --git a/src/btree.rs b/src/btree.rs
index f32f935..bfd6665 100644
--- a/src/btree.rs
+++ b/src/btree.rs
@@ -415,18 +415,16 @@ impl BTree {
 
 #[cfg(test)]
 mod tests {
+    use crate::btree::{BTree, BTreeBuilder};
     use crate::error::Error;
+    use tempfile::TempDir;
 
     #[test]
     fn search_works() -> Result<(), Error> {
-        use crate::btree::BTreeBuilder;
         use crate::node_type::KeyValuePair;
-        use std::path::Path;
 
-        let mut btree = BTreeBuilder::new()
-            .path(Path::new("/tmp/db"))
-            .b_parameter(2)
-            .build()?;
+        let dir = tempfile::tempdir()?; // Deleted on drop.
+        let mut btree = create_temp_btree(dir)?;
         btree.insert(KeyValuePair::new("a".to_string(), "shalom".to_string()))?;
         btree.insert(KeyValuePair::new("b".to_string(), "hello".to_string()))?;
         btree.insert(KeyValuePair::new("c".to_string(), "marhaba".to_string()))?;
@@ -444,14 +442,10 @@ mod tests {
 
     #[test]
     fn insert_works() -> Result<(), Error> {
-        use crate::btree::BTreeBuilder;
         use crate::node_type::KeyValuePair;
-        use std::path::Path;
 
-        let mut btree = BTreeBuilder::new()
-            .path(Path::new("/tmp/db"))
-            .b_parameter(2)
-            .build()?;
+        let dir = tempfile::tempdir()?; // Deleted on drop.
+        let mut btree = create_temp_btree(dir)?;
         btree.insert(KeyValuePair::new("a".to_string(), "shalom".to_string()))?;
         btree.insert(KeyValuePair::new("b".to_string(), "hello".to_string()))?;
         btree.insert(KeyValuePair::new("c".to_string(), "marhaba".to_string()))?;
@@ -502,15 +496,11 @@ mod tests {
 
     #[test]
     fn delete_works() -> Result<(), Error> {
-        use crate::btree::BTreeBuilder;
         use crate::error::Error;
         use crate::node_type::{Key, KeyValuePair};
-        use std::path::Path;
 
-        let mut btree = BTreeBuilder::new()
-            .path(Path::new("/tmp/db"))
-            .b_parameter(2)
-            .build()?;
+        let dir = tempfile::tempdir()?; // Deleted on drop.
+        let mut btree = create_temp_btree(dir)?;
         btree.insert(KeyValuePair::new("d".to_string(), "olah".to_string()))?;
         btree.insert(KeyValuePair::new("e".to_string(), "salam".to_string()))?;
         btree.insert(KeyValuePair::new("f".to_string(), "hallo".to_string()))?;
@@ -547,14 +537,10 @@ mod tests {
 
     #[test]
     fn delete_with_empty_sub_tree() -> Result<(), Error> {
-        use crate::btree::BTreeBuilder;
         use crate::node_type::{Key, KeyValuePair};
-        use std::path::Path;
 
-        let mut btree = BTreeBuilder::new()
-            .path(Path::new("/tmp/db"))
-            .b_parameter(2)
-            .build()?;
+        let dir = tempfile::tempdir()?; // Deleted on drop.
+        let mut btree = create_temp_btree(dir)?;
         btree.insert(KeyValuePair::new("a".to_string(), "shalom".to_string()))?;
         btree.insert(KeyValuePair::new("b".to_string(), "hello".to_string()))?;
         btree.insert(KeyValuePair::new("c".to_string(), "marhaba".to_string()))?;
@@ -576,11 +562,11 @@ mod tests {
         btree.delete(Key("a".to_string()))?;
         res = btree.search("a".to_string());
         assert!(matches!(res, Err(Error::KeyNotFound)));
-        
+
         btree.delete(Key("b".to_string()))?;
         res = btree.search("b".to_string());
         assert!(matches!(res, Err(Error::KeyNotFound)));
-        
+
         btree.delete(Key("c".to_string()))?;
         res = btree.search("c".to_string());
         assert!(matches!(res, Err(Error::KeyNotFound)));
@@ -594,4 +580,13 @@ mod tests {
         assert!(matches!(res, Err(Error::KeyNotFound)));
         Ok(())
     }
+
+    fn create_temp_btree(dir: TempDir) -> Result<BTree, Error> {
+        let db_path = dir.path().join("db");
+        let btree = BTreeBuilder::new()
+            .path(Box::leak(db_path.into_boxed_path()))
+            .b_parameter(2)
+            .build()?;
+        Ok(btree)
+    }
 }