throw err if dependency not listed

lib/plugins.js

@@ -23,20 +23,35 @@ module.exports = async (server, config, log, requireCwd) => {
   // use deptree to resolve the order in which the plugins load
   // based on their _dependencies:
   const deptree = new Deptree();
+  // use these to guarantee all deps are present:
+  let dependencies = [];
+  const names = [];
   pluginArr.forEach((plugin) => {
     // priority is deprecated:
     if (plugin._priority) {
       throw new Error(`"_priority" field used by ${plugin._name} is deprecated, please migrate your plugins to use the _dependencies format`);
     }
+    if (plugin._dependencies) {
+      dependencies = dependencies.concat(plugin._dependencies);
+    }
+    names.push(plugin._name);
     deptree.add(plugin._name, plugin._dependencies ? plugin._dependencies : []);
   });
+  // ensure all dependencies exist:
+  for (let i = 0; i < dependencies.length; i++) {
+    if (!names.includes(dependencies[i])) {
+      throw new Error(`Missing plugin dependency ${dependencies[i]}`);
+    }
+  }
   pluginArr = deptree.resolve().reduce((memo, pluginName) => {
     for (let i = 0; i < pluginArr.length; i++) {
-      if (pluginName === pluginArr[i]._name) {
-        memo.push(pluginArr[i]);
+      const plugin = pluginArr[i];
+      if (pluginName === plugin._name) {
+        memo.push(plugin);
         return memo;
       }
     }
+    return memo;
   }, []);
 
   /* eslint-disable no-await-in-loop */

test/brokenDependency/default.yaml

@@ -0,0 +1,6 @@
+order:
+  - 'first'
+plugins:
+  './test/plugins/loadMeFirst.js':
+    _dependencies:
+      - './test/plugins/bigfoot.js'

test/server-test.js

@@ -82,6 +82,16 @@ lab.test('error for circular plugin dependencies ', async() => {
   lab.fail();
 });
 
+lab.test('error for broken plugin dependencies ', async() => {
+  try {
+    await hapiconfi(Hapi, { configPath: `${__dirname}/brokenDependency` });
+  } catch (e) {
+    code.expect(e.toString()).to.include('Missing plugin dependency ./test/plugins/bigfoot.js');
+    return;
+  }
+  lab.fail();
+});
+
 lab.test('will throw an error if deprecated _priority field still used', async() => {
   try {
     await hapiconfi(Hapi, { configPath: `${__dirname}/deprecated` });