Fix cursor block height decoding in SortedTXCursor (#1950)

#1825

The `BlockHeight` was encoded in hexadecimal in response of
`transactions` endpoint and decoded with `u32::from_str` in parameter of
type `SortedTXCursor` which was preventing from making chained API
calls.
This PR, fixes this by decoding `BlockHeight` from hexadecimal form in
`SortedTXCursor`.

This bug wasn't catch by the test `tx::get_transactions()` because the
test was using only txs included in block 3 that has a string
representation that is the same in an hexadecimal and decimal encoding.
I added the creation of 10 blocks at start of the test so that now the
txs are included in blocks that have a hexadecimal and decimal encoding
form that differs.

I didn't spotted any hangs on the endpoint when the cursor is
initialized manually, however as we can't ask to start at a precise
block height without specifying a previous `tx_id` it's not very usable
to make manual search.

PS: This is my first contribution and so to what I saw my PR doesn't
brake anything else and I tried to follow the guidelines of the
repository, however maybe their things that I missed and so I'm very
open to criticise !

## Checklist
- [x] Breaking changes are clearly marked as such in the PR description
and changelog
- [x] New behavior is reflected in tests
- [x] [The specification](https://github.com/FuelLabs/fuel-specs/)
matches the implemented behavior (link update PR if changes are needed)

### Before requesting review
- [x] I have reviewed the code myself
- [x] I have created follow-up issues caused by this PR and linked them
here

### After merging, notify other teams

[Add or remove entries as needed]

- [ ] [Rust SDK](https://github.com/FuelLabs/fuels-rs/)
- [ ] [Sway compiler](https://github.com/FuelLabs/sway/)
- [ ] [Platform
documentation](https://github.com/FuelLabs/devrel-requests/issues/new?assignees=&labels=new+request&projects=&template=NEW-REQUEST.yml&title=%5BRequest%5D%3A+)
(for out-of-organization contributors, the person merging the PR will do
this)
- [ ] Someone else?

---------

Co-authored-by: Green Baneling <XgreenX9999@gmail.com>

CHANGELOG.md

@@ -6,6 +6,9 @@ and this project adheres to [Semantic Versioning](http://semver.org/).
 
 ## [Unreleased]
 
+### Fixed
+- [#1950](https://github.com/FuelLabs/fuel-core/pull/1950): Fix cursor `BlockHeight` encoding in `SortedTXCursor`
+
 ## [Version 0.28.0]
 
 ### Changed

crates/fuel-core/src/schema/scalars.rs

@@ -145,9 +145,8 @@ impl CursorType for SortedTxCursor {
             s.split_once('#').ok_or("Incorrect format provided")?;
 
         Ok(Self::new(
-            u32::from_str(block_height)
-                .map_err(|_| "Failed to decode block_height")?
-                .into(),
+            BlockHeight::from_str(block_height)
+                .map_err(|_| "Failed to decode block_height")?,
             Bytes32::decode_cursor(tx_id)?,
         ))
     }

tests/tests/tx.rs

@@ -275,28 +275,55 @@ async fn get_transactions() {
     let charlie = Address::from([3; 32]);
 
     let mut context = TestContext::new(100).await;
+    // Produce 10 blocks to ensure https://github.com/FuelLabs/fuel-core/issues/1825 is tested
+    context
+        .srv
+        .shared
+        .poa_adapter
+        .manually_produce_blocks(
+            None,
+            Mode::Blocks {
+                number_of_blocks: 10,
+            },
+        )
+        .await
+        .expect("Should produce block");
     let tx1 = context.transfer(alice, charlie, 1).await.unwrap();
     let tx2 = context.transfer(charlie, bob, 2).await.unwrap();
     let tx3 = context.transfer(bob, charlie, 3).await.unwrap();
     let tx4 = context.transfer(bob, charlie, 3).await.unwrap();
     let tx5 = context.transfer(charlie, alice, 1).await.unwrap();
     let tx6 = context.transfer(alice, charlie, 1).await.unwrap();
 
-    // there are 12 transactions
+    // Skip the 10 first txs included in the tx pool by the creation of the 10 blocks above
+    let page_request = PaginationRequest {
+        cursor: None,
+        results: 10,
+        direction: PageDirection::Forward,
+    };
+    let client = context.client;
+    let response = client.transactions(page_request.clone()).await.unwrap();
+    assert_eq!(response.results.len(), 10);
+    assert!(!response.has_previous_page);
+    assert!(response.has_next_page);
+
+    // Now, there are 12 transactions
     // [
     //  tx1, coinbase_tx1, tx2, coinbase_tx2, tx3, coinbase_tx3,
     //  tx4, coinbase_tx4, tx5, coinbase_tx5, tx6, coinbase_tx6,
     // ]
 
     // Query for first 6: [tx1, coinbase_tx1, tx2, coinbase_tx2, tx3, coinbase_tx3]
-    let client = context.client;
-    let page_request = PaginationRequest {
-        cursor: None,
+    let first_middle_page_request = PaginationRequest {
+        cursor: response.cursor.clone(),
         results: 6,
         direction: PageDirection::Forward,
     };
 
-    let response = client.transactions(page_request.clone()).await.unwrap();
+    let response = client
+        .transactions(first_middle_page_request.clone())
+        .await
+        .unwrap();
     let transactions = &response
         .results
         .iter()
@@ -308,9 +335,9 @@ async fn get_transactions() {
     // coinbase_tx2
     assert_eq!(transactions[4], tx3);
     // coinbase_tx3
-    // Check pagination state for first page
+    // Check pagination state for middle page
     assert!(response.has_next_page);
-    assert!(!response.has_previous_page);
+    assert!(response.has_previous_page);
 
     // Query for second page 2 with last given cursor: [tx4, coinbase_tx4, tx5, coinbase_tx5]
     let page_request_middle_page = PaginationRequest {
@@ -319,10 +346,10 @@ async fn get_transactions() {
         direction: PageDirection::Forward,
     };
 
-    // Query backwards from last given cursor [3]: [tx3, coinbase_tx2, tx2, coinbase_tx1, tx1]
+    // Query backwards from last given cursor [3]: [tx3, coinbase_tx2, tx2, coinbase_tx1, tx1, tx_block_creation_10, tx_block_creation_9, ...]
     let page_request_backwards = PaginationRequest {
         cursor: response.cursor.clone(),
-        results: 6,
+        results: 16,
         direction: PageDirection::Backward,
     };