checkpoint: adds null check and count to main procedure

Author: bjacobgordon

vitest/ensure-all-units-have-test-companion.ts

@@ -13,7 +13,11 @@ import {
 
 const unitsWithoutCompanions = TestableUnit.getAllThatAreMissingTestCompanion();
 
-if (
+if (unitsWithoutCompanions === null) {
+  console.error('Could not determine which units are missing test companions');
+  process.exit(1);
+}
+else if (
   unitsWithoutCompanions.length === 0
 ) process.exit(0);
 
@@ -24,5 +28,5 @@ const serializedUnitsWithoutCompanions = unitsWithoutCompanions
   .map($0 => format($0).replace(pathToProjectRoot, ''))
   .join('\n');
 
-console.error(`The following units have no test companion:\n${serializedUnitsWithoutCompanions}`);
+console.error(`The following ${unitsWithoutCompanions.length.toString()} unit(s) have no test companion:\n${serializedUnitsWithoutCompanions}`);
 process.exit(1);