Fix bug in bridge_replace fn, test

crates/lox-library/src/lib.rs

@@ -556,8 +556,24 @@ impl BridgeAuth {
                     }
                     res = ReplaceSuccess::Replaced
                 } else if !self.bridge_table.spares.is_empty() {
+                    // First get the bucketnums for the replacement bridge in case it is a spare
+                    let mut bucketnums: Vec<u32> = Vec::new();
+                    for (bucketnum, _) in positions.iter() {
+                        bucketnums.push(*bucketnum);
+                    }
                     // Get the first spare and remove it from the spares set.
-                    let spare = *self.bridge_table.spares.iter().next().unwrap();
+                    let mut spare = *self.bridge_table.spares.iter().next().unwrap();
+                    // Check that the first spare in the list of spares is not the one to be replaced
+                    if bucketnums.contains(&spare) {
+                        // If it is, take the last spare instead
+                        spare = *self.bridge_table.spares.iter().last().unwrap();
+                        // If this is the same bucketnum, there is only one spare bucket with the bridge
+                        // to be replaced in it, so don't replace it.
+                        if bucketnums.contains(&spare) {
+                            res = ReplaceSuccess::NotReplaced;
+                            return res;
+                        }
+                    }
                     self.bridge_table.spares.remove(&spare);
                     self.bridge_table.recycleable_keys.push(spare);
                     // Get the actual bridges from the spare bucket
@@ -596,6 +612,7 @@ impl BridgeAuth {
                     }
                     res = ReplaceSuccess::Replaced
                 } else {
+                    println!("No available bridges");
                     // If there are no available bridges that can be assigned here, the only thing
                     // that can be done is return an indication that updating the gone bridge
                     // didn't work.

crates/lox-library/src/tests.rs

@@ -1032,13 +1032,15 @@ fn test_update_bridge() {
 #[test]
 fn test_bridge_replace() {
     // Create 3 open invitation buckets and 3 spare buckets
-    let cases = vec!["not found", "available", "unallocated", "failed", "spare"];
+    let cases = vec!["not found", "available", "unallocated", "spare", "failed"];
+    let num_buckets = 5;
+    let hot_spare = 0;
     for case in cases {
         let mut th: TestHarness;
-        if case != "failed" {
+        if String::from(case) != "failed" {
             th = TestHarness::new();
         } else {
-            th = TestHarness::new_buckets(5, 0);
+            th = TestHarness::new_buckets(num_buckets, hot_spare);
         }
 
         // Randomly select a bridge to replace
@@ -1047,6 +1049,7 @@ fn test_bridge_replace() {
         while !th.ba.bridge_table.buckets.contains_key(&num) {
             num = rand::thread_rng().gen_range(0..th.ba.bridge_table.counter);
         }
+        println!("chosen num is: {:?}", num);
         let replaceable_bucket = *th.ba.bridge_table.buckets.get(&num).unwrap();
         let replacement_bridge = &replaceable_bucket[0];
         assert!(
@@ -1182,7 +1185,7 @@ fn test_bridge_replace() {
                     "Extra spare bridges not added to unallocated bridges"
                 );
 
-                println!("Successfully added unallocated bridgeline");
+                println!("Successfully added bridgeline from spare");
             }
             "failed" => {
                 // Case four: available_bridge == None and unallocated_bridges == None and spare buckets == None