Rerun macros babel plugins if dependencies change

dependencySatisfies can become invalid if babel caches the macros
plugin + the dependency that is being checked for changes its package
version. This adds a cache busting plugin that tracks a hash of the
contents of the apps lock file so any changes to dependencies will
bust the cache.

Fixes: #906

packages/macros/src/babel-plugin-cache-busting.ts

@@ -0,0 +1,3 @@
+export default function makePlugin(): any {
+  return {};
+}

packages/macros/src/ember-addon-main.ts

@@ -1,4 +1,6 @@
+import fs from 'fs';
 import { join } from 'path';
+import crypto from 'crypto';
 import { MacrosConfig, isEmbroiderMacrosPlugin } from './node';
 
 export = {
@@ -70,6 +72,30 @@ export = {
       let appInstance = this._findHost();
       let source = appOrAddonInstance.root || appOrAddonInstance.project.root;
       babelPlugins.unshift(MacrosConfig.for(appInstance).babelPluginConfig(source));
+
+      let yarnLockPath = join(appInstance.project.root, 'yarn.lock');
+      let npmLockPath = join(appInstance.project.root, 'package-lock.json');
+      let packagePath = join(appInstance.project.root, 'package.json');
+      let lockFileBuffer;
+
+      if (fs.existsSync(yarnLockPath)) {
+        lockFileBuffer = fs.readFileSync(yarnLockPath);
+      } else if (fs.existsSync(npmLockPath)) {
+        lockFileBuffer = fs.readFileSync(npmLockPath);
+      } else {
+        // no lock file found, using package.json as a fall back
+        lockFileBuffer = fs.readFileSync(packagePath);
+      }
+
+      // @embroider/macros provides a macro called dependencySatisfies which checks if a given
+      // package name satisfies a given semver version range. Due to the way babel caches this can
+      // cause a problem where the macro plugin does not run (because it has been cached) but the version
+      // of the dependency being checked for changes (due to installing a different version). This will lead to
+      // the old evaluated state being used which might be invalid. This cache busting plugin keeps track of a
+      // hash representing the lock file of the app and if it ever changes forces babel to rerun its plugins.
+      // more information in issue #906
+      let cacheKey = crypto.createHash('sha256').update(lockFileBuffer).digest('hex');
+      babelPlugins.push([require.resolve('./babel-plugin-cache-busting'), { version: cacheKey }]);
     }
   },