tests: Make the grafted test independent of block numbers

We used to use hardcoded POIs which required us to use fixed block
hashes. But since commit f145736 that's no longer needed and we can just
use whatever block hashes the chain has, making the test setup less
fragile.

Author: lutter

tests/tests/integration_tests.rs

@@ -865,25 +865,23 @@ async fn test_subgraph_grafting(ctx: TestContext) -> anyhow::Result<()> {
 
     assert!(subgraph.healthy);
 
-    // Fixed block hashes from deterministic Anvil config
-    let block_hashes: Vec<&str> = vec![
-        "e26fccbd24dcc76074b432becf29cad3bcba11a8467a7b770fad109c2b5d14c2",
-        "249dbcbee975c22f8c9cc937536945ca463568c42d8933a3f54129dec352e46b",
-        "408675f81c409dede08d0eeb2b3420a73b067c4fa8c5f0fc49ce369289467c33",
-    ];
+    // Fetch block hashes from the chain
+    let mut block_hashes: Vec<String> = Vec::new();
+    for i in 1..4 {
+        let hash = get_block_hash(i)
+            .await
+            .ok_or_else(|| anyhow!("Failed to get block hash for block {}", i))?;
+        block_hashes.push(hash);
+    }
 
     // The deployment hash is dynamic (depends on the base subgraph's hash)
     let deployment_hash = DeploymentHash::new(&subgraph.deployment).unwrap();
 
-    // Compute the expected POI values dynamically
+    // Compute the expected POIs using the actual block hashes
     let expected_pois = compute_expected_pois(&deployment_hash, &block_hashes);
 
     for i in 1..4 {
-        let block_hash = get_block_hash(i).await.unwrap();
-        // We need to make sure that the preconditions for POI are fulfilled
-        // namely that the blockchain produced the proper block hashes for the
-        // blocks of which we will check the POI.
-        assert_eq!(block_hash, block_hashes[(i - 1) as usize]);
+        let block_hash = &block_hashes[(i - 1) as usize];
 
         const FETCH_POI: &str = r#"
         query proofOfIndexing($subgraph: String!, $blockNumber: Int!, $blockHash: String!, $indexer: String!) {
@@ -937,7 +935,7 @@ async fn test_subgraph_grafting(ctx: TestContext) -> anyhow::Result<()> {
 /// POI algorithm transition:
 /// - Blocks 0-2: Legacy POI digests (from base subgraph)
 /// - Block 3+: Fast POI algorithm with transition from Legacy
-fn compute_expected_pois(deployment_hash: &DeploymentHash, block_hashes: &[&str]) -> Vec<String> {
+fn compute_expected_pois(deployment_hash: &DeploymentHash, block_hashes: &[String]) -> Vec<String> {
     let logger = Logger::root(Discard, o!());
     let causality_region = "ethereum/test";