Add find_unused_deps monorepo script

packages/monorepo-scripts/package.json

@@ -11,9 +11,11 @@
         "build": "tsc",
         "test:publish": "run-s build script:publish",
         "convert_changelogs": "run-s build script:convert_changelogs",
+        "find_unused_deps": "run-s build script:find_unused_deps",
         "script:deps_versions": "node ./lib/deps_versions.js",
         "script:publish": "IS_DRY_RUN=true node ./lib/publish.js",
-        "script:convert_changelogs": "node ./lib/convert_changelogs.js"
+        "script:convert_changelogs": "node ./lib/convert_changelogs.js",
+        "script:find_unused_deps": "node ./lib/find_unused_dependencies.js"
     },
     "repository": {
         "type": "git",
@@ -30,6 +32,7 @@
         "@types/glob": "^5.0.33",
         "@types/node": "^8.0.53",
         "@types/rimraf": "^2.0.2",
+        "depcheck": "^0.6.9",
         "lerna-get-packages": "^1.0.0",
         "npm-run-all": "^4.1.2",
         "shx": "^0.2.2",
@@ -37,6 +40,7 @@
         "typescript": "2.7.1"
     },
     "dependencies": {
+        "@types/depcheck": "^0.6.0",
         "async-child-process": "^1.1.1",
         "chalk": "^2.3.0",
         "es6-promisify": "^5.0.0",

packages/monorepo-scripts/src/find_unused_dependencies.ts

@@ -0,0 +1,44 @@
+#!/usr/bin/env node
+
+import * as depcheck from 'depcheck';
+import * as fs from 'fs';
+import lernaGetPackages = require('lerna-get-packages');
+import * as _ from 'lodash';
+import { exec as execAsync } from 'promisify-child-process';
+
+import { constants } from './constants';
+import { utils } from './utils';
+
+const IGNORE_PACKAGES = ['@0xproject/deployer'];
+
+(async () => {
+    utils.log('*** NOTE: Not all deps listed here are actually not required. ***');
+    utils.log("*** `depcheck` isn't perfect so double check before actually removing any. ***\n");
+    const lernaPackages = lernaGetPackages(constants.monorepoRootPath);
+    for (const lernaPackage of lernaPackages) {
+        if (_.includes(IGNORE_PACKAGES, lernaPackage.package.name)) {
+            continue; // skip
+        }
+        utils.log(`Checking ${lernaPackage.package.name} for unused deps. This might take a while...`);
+
+        const configs = {};
+        const result: any = await depcheckAsync(lernaPackage.location, configs);
+        if (!_.isEmpty(result.dependencies)) {
+            _.each(result.dependencies, dep => {
+                utils.log(dep);
+            });
+        }
+        utils.log('\n');
+    }
+})().catch(err => {
+    utils.log(err);
+    process.exit(1);
+});
+
+async function depcheckAsync(path: string, opts: any) {
+    return new Promise<void>((resolve, reject) => {
+        depcheck(path, opts, (unused: any) => {
+            resolve(unused);
+        });
+    });
+}