ci: fix job that checks anvil state is up-to-date (#252)

### Motivation
The previous CI job that checked whether the anvil state was up to date
was actually not performing any comparison at all (it was mistakenly
comparing empty files).

Checking that the anvil state is up to date by re-generating it and
comparing it with the existing one was not very practical since this
approach is very time-sensitive: any difference in the timestamps
generates a different state, which the CI wrongly takes as an outdated
state.

### What Changed?
This PR introduces the following changes in the CI:
* Removes the step that compares the anvil state in the tests CI job,
and simply checks that the script to generate the state works.
* Adds a new job that checks whether the anvil state is updated (it runs
only when the contracts change).


### Reviewer Checklist

- [ ] New features are tested and documented
- [ ] PR updates the changelog with a description of changes
- [ ] PR has one of the `changelog-X` labels (if applies)
- [ ] Code deprecates any old functionality before removing it

---------

Co-authored-by: Tomás Grüner <[email protected]>

.github/workflows/check-anvil-dump.yml

@@ -0,0 +1,42 @@
+name: Check anvil dump is up-to-date
+
+on:
+  push:
+    branches: [main]
+
+  pull_request:
+    branches: [ '**' ]
+
+jobs:
+  check:
+    name: Check anvil dump state is up to date
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      # This step is needed to know if the contracts were changed.
+      - uses: dorny/paths-filter@v3
+        id: filter
+        with:
+          filters: |
+            contracts:
+              - 'crates/contracts/lib/**'
+              - 'crates/contracts/script/**'
+              - 'crates/contracts/src/**'
+      
+      # This step runs only if some contract changed.
+      # It checks the diff in the anvil state file.
+      # If the diff is null, that means the anvil state has not changed,
+      # i.e. the anvil state outdated and therefore this step will fail.
+      # Note: if the git diff fails to fetch the changes, then the step will also fail.
+      - name: Check the anvil dump has changed
+        if: steps.filter.outputs.contracts == 'true'
+        working-directory: crates/contracts/anvil/contracts_deployed_anvil_state.json
+        run: |
+          if [ -z "$(git diff origin/${{ github.event.pull_request.base.ref }} -- state.json)" ]; then
+            echo "The anvil dump is outdated";
+            exit 1
+          fi

.github/workflows/integration.yml

@@ -98,15 +98,12 @@ jobs:
           name: coverage-summary
           path: coverage.zip
 
-  check_anvil_dump:
+  generate_anvil_dump:
     strategy:
       fail-fast: true
 
-    name: Check anvil dump state is up to date
+    name: Generate anvil state
     runs-on: ubuntu-latest
-    defaults:
-      run:
-        working-directory: ./crates/contracts/anvil
     steps:
       - uses: actions/checkout@v4
         with:
@@ -116,18 +113,6 @@ jobs:
         uses: foundry-rs/foundry-toolchain@v1
         with:
           version: stable
-
-      - name: Backup existing anvil dump state
-        run: |
-          cd contracts_deployed_anvil_state.json
-          cp state.json previous_state.json
 
-      - name: Generate new anvil dump state
-        run: ./deploy-contracts-save-anvil-state.sh
-
-      - name: Check whether the anvil dump state has changed
-        run: |
-          cd contracts_deployed_anvil_state.json
-          jq --sort-keys . previous_state.json > previous_state.json
-          jq --sort-keys . state.json > state.json
-          diff previous_state.json state.json
+      - name: Generate anvil state
+        run: make deploy-contracts-to-anvil-and-save-state