JS: Add test case

Author: asgerf

javascript/ql/test/library-tests/MalformedPackageJson/Test.expected

@@ -0,0 +1,4 @@
+files
+| nullContents/package.json:0:0:0:0 | nullContents/package.json |
+| tst.js:0:0:0:0 | tst.js |
+packageJsons

javascript/ql/test/library-tests/MalformedPackageJson/Test.ql

@@ -0,0 +1,5 @@
+import javascript
+
+query File files() { any() }
+
+query PackageJSON packageJsons() { any() }

javascript/ql/test/library-tests/MalformedPackageJson/nullContents/package.json

@@ -0,0 +1 @@
+null

javascript/ql/test/library-tests/MalformedPackageJson/tst.js

@@ -0,0 +1,2 @@
+// This file is just here to ensure some JS code is extracted
+let x = 'hey';