doubly-linked-list: improve leak check (#2043)

senekor · web-flow · commit c8dd24149916 · 2025-02-26T20:20:59.000+01:00
Previously the check may fail due to an underflow in the subtraction,
rather than the assert.
diff --git a/exercises/practice/doubly-linked-list/tests/step_4_leak_test_2.rs b/exercises/practice/doubly-linked-list/tests/step_4_leak_test_2.rs
@@ -19,8 +19,7 @@ fn drop_no_leaks() {
     drop(list);
 
     let allocated_after = ALLOCATED.load(SeqCst);
-    let leaked_bytes = allocated_before - allocated_after;
-    assert!(leaked_bytes == 0);
+    assert_eq!(allocated_before, allocated_after);
 }
 
 // Defines a wrapper around the global allocator that counts allocations

Original file line number	Diff line number	Diff line change
`@@ -19,8 +19,7 @@ fn drop_no_leaks() {`
`19`	`19`	`drop(list);`
`20`	`20`
`21`	`21`	`let allocated_after = ALLOCATED.load(SeqCst);`
`22`		`- let leaked_bytes = allocated_before - allocated_after;`
`23`		`- assert!(leaked_bytes == 0);`
	`22`	`+ assert_eq!(allocated_before, allocated_after);`
`24`	`23`	`}`
`25`	`24`
`26`	`25`	`// Defines a wrapper around the global allocator that counts allocations`