fix(core): Correctly search for loaded modules in node 12 (#2612)

Node 12 has corrected how the require.resolve function applied un-documented behavior, so
that it is needed to make relative search paths explicit (./).

Related: nodejs/node#27583

packages/@aws-cdk/cdk/lib/node-version.ts

@@ -0,0 +1,19 @@
+import process = require('process');
+
+// process.versions.node is like "12.3.1"
+const [strMajor, strMinor, strPatch, ] = process.versions.node.split('.');
+
+/**
+ * The major version of the node runtime.
+ */
+export const major = Number(strMajor);
+
+/**
+ * The minor version of the node runtime.
+ */
+export const minor = Number(strMinor);
+
+/**
+ * The revision of the node runtime.
+ */
+export const patch = Number(strPatch);

packages/@aws-cdk/cdk/lib/runtime-info.ts

@@ -1,4 +1,5 @@
 import cxapi = require('@aws-cdk/cx-api');
+import { major as nodeMajorVersion } from './node-version';
 
 /**
  * Returns a list of loaded modules and their versions.
@@ -55,7 +56,11 @@ function findNpmPackage(fileName: string): { name: string, version: string, priv
   const paths = mod.paths.map(stripNodeModules);
 
   try {
-    const packagePath = require.resolve('package.json', { paths });
+    const packagePath = require.resolve(
+      // Resolution behavior changed in node 12.0.0 - https://github.com/nodejs/node/issues/27583
+      nodeMajorVersion >= 12 ? './package.json' : 'package.json',
+      { paths }
+    );
     return require(packagePath);
   } catch (e) {
     return undefined;

packages/@aws-cdk/cdk/package.json

@@ -67,7 +67,7 @@
   },
   "license": "Apache-2.0",
   "devDependencies": {
-    "@types/lodash": "^4.14.123",
+    "@types/lodash": "^4.14.130",
     "cdk-build-tools": "^0.31.0",
     "cfn2ts": "^0.31.0",
     "fast-check": "^1.14.0",