chore(ci): fail properly in external-repo-checks (#6988)

.github/scripts/check_test_results.sh

@@ -17,6 +17,7 @@ if [ -f $1 ] && [ -f $2 ]; then
     echo "Error: test failures don't match expected failures"
     echo "Lines prefixed with '>' are new test failures (you could add them to '$1')"
     echo "Lines prefixed with '<' are tests that were expected to fail but passed (you could remove them from '$1')"
+    exit -1
   fi
 elif [ -f $1 ]; then
   # Only the expected file exists, which means the actual test couldn't be compiled.
@@ -35,4 +36,4 @@ else
   # Both files don't exists, which means we are expecting the external library not
   # to compile, and it didn't, so all is good.
   exit 0
-fi
+fi

.github/workflows/test-js-packages.yml

@@ -597,7 +597,12 @@ jobs:
       - name: Run nargo test
         working-directory: ./test-repo/${{ matrix.project.path }}
         run: |
-          nargo test --silence-warnings --skip-brillig-constraints-check --format json ${{ matrix.project.nargo_args }} | tee ${{ github.workspace }}/noir-repo/.github/critical_libraries_status/${{ matrix.project.repo }}/${{ matrix.project.path }}.actual.jsonl
+          output_file=${{ github.workspace }}/noir-repo/.github/critical_libraries_status/${{ matrix.project.repo }}/${{ matrix.project.path }}.actual.jsonl
+          nargo test --silence-warnings --skip-brillig-constraints-check --format json ${{ matrix.project.nargo_args }} | tee $output_file
+          if [ ! -s $output_file ]; then
+            # The file is empty so we delete it to signal that `nargo test` failed before it could run any tests
+            rm -f $output_file
+          fi
         env:
           NARGO_IGNORE_TEST_FAILURES_FROM_FOREIGN_CALLS: true