!fixup

eyeball-im-util/src/vector/limit.rs

@@ -184,7 +184,7 @@ where
                 }
             }
             VectorDiff::PopBack => {
-                if is_full {
+                if length > limit {
                     // Let's ignore the diff.
                 } else {
                     self.push_ready_value(VectorDiff::PopBack);

eyeball-im-util/tests/it/limit.rs

@@ -417,3 +417,53 @@ fn pop_front() {
     drop(ob);
     assert_closed!(sub);
 }
+
+#[test]
+fn pop_back() {
+    let mut ob = ObservableVector::<usize>::new();
+    let mut limit = Observable::new(0);
+    let mut sub =
+        DynamicLimit::new(ob.clone(), ob.subscribe().into_stream(), Observable::subscribe(&limit));
+
+    // Add 4 values.
+    ob.append(vector![10, 11, 12, 13]);
+
+    // Set limit to 2.
+    Observable::set(&mut limit, 3);
+
+    // Observe 2 values.
+    assert_next_eq!(sub, VectorDiff::Append { values: vector![10, 11, 12] });
+
+    // Remove 1 value.
+    ob.pop_back();
+
+    // Observe nothing.
+    assert_pending!(sub);
+
+    // Remove 1 value.
+    ob.pop_back();
+
+    // Observe nothing.
+    assert_next_eq!(sub, VectorDiff::PopBack);
+
+    // Remove 1 value.
+    ob.pop_back();
+
+    // Observe nothing.
+    assert_next_eq!(sub, VectorDiff::PopBack);
+
+    // Check the content of the vector.
+    {
+        let expected = vector![10];
+        assert_eq!(*ob, expected);
+
+        Observable::set(&mut limit, 0);
+        assert_next_eq!(sub, VectorDiff::Truncate { length: 0 });
+
+        Observable::set(&mut limit, 42);
+        assert_next_eq!(sub, VectorDiff::Append { values: expected });
+    }
+
+    drop(ob);
+    assert_closed!(sub);
+}