feat: run command on changes

based on dependencies, devDependencies, and hashes of other included files

src/data.js

@@ -29,6 +29,11 @@ exports.read = (fileRoot, ident) => {
 };
 
 exports.write = (fileRoot, ident, payload) => {
-  console.log('WRITE', { fileRoot, ident, payload });
-  throw new Error('Data write not implemented');
+  const filePath = path.join(fileRoot, CONFIG_FILENAME);
+  const existingCache = JSON.parse(fs.readFileSync(filePath));
+
+  // update the cache
+  existingCache[ident] = payload;
+
+  fs.writeFileSync(filePath, JSON.stringify(existingCache));
 };