tests: Fix grafted integration test with dynamic POI computation

The grafted test was failing because it used hardcoded POI values that
became stale when the base subgraph's deployment hash changed. This commit:

- Adds `patch_sources()` to dynamically patch source subgraph placeholders
  (e.g., `@base@`) with actual deployment hashes at runtime
- Modifies `deploy()` and `prepare()` to accept source mappings
- Replaces hardcoded POI values with dynamic computation using the same
  algorithm graph-node uses (matching spec version transitions)
- Updates Anvil to v1.4.0 for deterministic block hashes

The POI computation correctly handles the Legacy→Fast algorithm transition
when grafting from spec 0.0.5 to 0.0.6, starting from block 0 (genesis).

Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Author: lutter

tests/docker-compose.yml

@@ -22,7 +22,7 @@ services:
   anvil:
     # Pinned to specific version since newer versions do not produce
     # deterministic block hashes. Unpin once that's fixed upstream
-    image: ghcr.io/foundry-rs/foundry:v1.2.3
+    image: ghcr.io/foundry-rs/foundry:v1.4.0
     ports:
       - '3021:8545'
     command: "'anvil --host 0.0.0.0 --gas-limit 100000000000 --base-fee 1 --block-time 2 --timestamp 1743944919 --mnemonic \"test test test test test test test test test test test junk\"'"

tests/integration-tests/grafted/subgraph.yaml

@@ -26,5 +26,5 @@ dataSources:
 features:
   - grafting
 graft:
-  base: QmTQbJ234d2Po7xKZS5wKPiYuMYsCAqqY4df5czESjEXn4
+  base: '@base@'
   block: 2

tests/src/subgraph.rs

@@ -47,16 +47,41 @@ impl Subgraph {
         Ok(())
     }
 
+    /// Patch source subgraph placeholders in the manifest with their deployment hashes.
+    /// This must be called after `patch()` since it reads from `subgraph.yaml.patched`.
+    pub fn patch_sources(dir: &TestFile, sources: &[(String, String)]) -> anyhow::Result<()> {
+        if sources.is_empty() {
+            return Ok(());
+        }
+
+        let patched_path = dir.path.join("subgraph.yaml.patched");
+        let mut content = fs::read_to_string(&patched_path)?;
+
+        for (placeholder, deployment_hash) in sources {
+            let repl = format!("@{}@", placeholder);
+            content = content.replace(&repl, deployment_hash);
+        }
+
+        fs::write(&patched_path, content)?;
+        Ok(())
+    }
+
     /// Prepare the subgraph for deployment by patching contracts and checking for subgraph datasources
     pub async fn prepare(
         name: &str,
         contracts: &[Contract],
+        sources: Option<&[(String, String)]>,
     ) -> anyhow::Result<(TestFile, String, bool)> {
         let dir = Self::dir(name);
         let name = format!("test/{name}");
 
         Self::patch(&dir, contracts).await?;
 
+        // Patch source subgraph placeholders if provided
+        if let Some(sources) = sources {
+            Self::patch_sources(&dir, sources)?;
+        }
+
         // Check if subgraph has subgraph datasources
         let yaml_content = fs::read_to_string(dir.path.join("subgraph.yaml.patched"))?;
         let yaml: serde_yaml::Value = serde_yaml::from_str(&yaml_content)?;
@@ -68,9 +93,15 @@ impl Subgraph {
         Ok((dir, name, has_subgraph_datasource))
     }
 
-    /// Deploy the subgraph by running the required `graph` commands
-    pub async fn deploy(name: &str, contracts: &[Contract]) -> anyhow::Result<String> {
-        let (dir, name, has_subgraph_datasource) = Self::prepare(name, contracts).await?;
+    /// Deploy the subgraph by running the required `graph` commands.
+    /// If `sources` is provided, the deployment hashes will be used to patch
+    /// source subgraph placeholders (e.g., `@source-subgraph@`) in the manifest.
+    pub async fn deploy(
+        name: &str,
+        contracts: &[Contract],
+        sources: Option<&[(String, String)]>,
+    ) -> anyhow::Result<String> {
+        let (dir, name, has_subgraph_datasource) = Self::prepare(name, contracts, sources).await?;
 
         // graph codegen subgraph.yaml
         let mut prog = Command::new(&CONFIG.graph_cli);