Check api example cbor in CI

Author: ch1bo

.github/workflows/check-examples.sh

@@ -0,0 +1,27 @@
+#!/usr/bin/env bash
+set -uo pipefail
+
+# Check consistency of .cbor files against .cddl in the repository.
+
+# TODO: check whether 'cddl' is installed
+
+# Check that given cbor is valid against all given cddls files concatenated
+function check_cbor() {
+    local cbor_file=$1
+    shift
+    local cddl_files=("$@")
+    local cddl=$(cat "${cddl_files[@]}")
+    # NOTE: cddl spams stdout on invalid cbor, so we drop everything after '-- cannot complete'
+    out=$(cddl <(echo "${cddl}") validate <(xxd -r -p "${cbor_file}") 2> /dev/null | \
+            awk -v RS='--' 'NR==1{print} NR==2{exit}') 
+    if [ $? -ne 0 ]; then
+        echo "Invalid cbor file: ${cbor_file}"
+        echo "Error: ${out%--*}"
+        printf "CDDL: \n${cddl}"
+        exit 1
+    fi
+}
+
+cd src/api
+check_cbor examples/getSystemStart/query.cbor cddl/local-state-query.cddl cddl/getSystemStart.cddl
+check_cbor examples/getSystemStart/result.cbor cddl/local-state-query.cddl cddl/getSystemStart.cddl

.github/workflows/check-examples.yaml

@@ -0,0 +1,29 @@
+name: Check cbor examples
+
+on:
+  pull_request:
+  push:
+    branches:
+    - main
+  schedule:
+    # Everyday at 4:00 AM
+    - cron: "0 4 * * *"
+
+jobs:
+  check-cbor-examples:
+    name: Check cbor examples
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+
+    - name: Install nix
+      uses: cachix/install-nix-action@V27
+      with:
+        extra_nix_config: |
+          accept-flake-config = true
+          log-lines = 1000
+
+    - name: Enter nix shell
+      uses: nicknovitski/nix-develop@v1
+
+    - run: ./.github/workflows/check-examples.sh

flake.nix

@@ -25,14 +25,18 @@
                 mdbook-katex
                 mdbook-alerts
                 mdbook-toc
+
+                # to validate cbor / cddl
+                cddl
+                xxd
               ];
               phases = [ "unpackPhase" "buildPhase" ];
               buildPhase = ''
                 mdbook build -d $out
               '';
             }
           );
-        defaultPackage = packages.mdbook;
+        packages.default = packages.mdbook;
       }
     );
 }

src/client/node-to-client/state-query/getSystemStart.cddl

@@ -1,4 +1,4 @@
-$query /= 1
+$query /= [1]
 $result /= [year, dayOfYear, timeOfDayPico]
 
 year = bigint

src/client/node-to-client/state-query/messages.cddl

@@ -18,9 +18,6 @@ acquireFailurePointNotOnChain = 1
 failure      = acquireFailurePointTooOld
              / acquireFailurePointNotOnChain
 
-$query        = any
-$result       = any
-
 msgAcquire   = [0, point]
              / [8]
              / [10]