Search a Flutter project for unused dependencies

unused_dependencies.js

/// Finds unused dependencies from pubspec.yaml
///
/// Achieves this by parsing pubspec.yaml and recursively
/// searching the lib folder for an import statement that
/// contains the name of each package. Prints out the results.
const fs = require("fs");
const YAML = require("yaml");
const { execSync } = require("child_process");

/// Read pubspec.yaml
const file = fs.readFileSync("../pubspec.yaml", "utf8");
const doc = YAML.parseDocument(file);

/// Convenience function to extract keys from a top level key
///
/// Eg, used for getting all the package names from the "dependencies" key
function extractKeys(topLevelKey) {
  return doc.get(topLevelKey).items.map(({ key }) => key.value);
}

/// Extract deps, overrides, and development deps
const deps = extractKeys("dependencies");
const depOverrides = extractKeys("dependency_overrides");
const devDeps = extractKeys("dev_dependencies");

/// Search the project to see if it's using a certain package
/// by checking for an import statement
function searchProjectForUse(packageName) {
  try {
    /// Will throw error if a file isn't found that contains an import statement
    execSync(`grep -Ril "import 'package:${packageName}" ../lib`);
    return true;
  } catch {
    return false;
  }
}

/// Take a list of package names and search the project for use,
/// return a list of unused packages.
function printListOfUnusedPackagesWithIndents(listOfPackages) {
  listOfPackages.forEach((packageName) => {
    const isUsingPackage = searchProjectForUse(packageName);
    if (isUsingPackage == false) {
      console.log(`  ${packageName}`);
    }
  });
}

console.log(`# Checking pubspec.yaml for dependencies that 
# aren't referenced in import statements...`);

console.log("\ndependencies:");
printListOfUnusedPackagesWithIndents(deps);

console.log("\ndependency_overrides:");
printListOfUnusedPackagesWithIndents(depOverrides);

/// Skip dev_dependencies because they are not imported into project files
// console.log("\ndev_dependencies:");
// printListOfUnusedPackagesWithIndents(devDeps);