fixup: add test-case for require() resolving via package.json

Author: JakobJingleheimer

test/fixtures/packages/cjs-main-no-index/main.js

@@ -0,0 +1 @@
+module.exports = 42;

test/fixtures/packages/cjs-main-no-index/other.js

@@ -0,0 +1,3 @@
+const answer = require('./');
+
+module.exports = answer+1;

test/fixtures/packages/cjs-main-no-index/package.json

@@ -0,0 +1,5 @@
+{
+  "name": "main-no-index",
+  "main": "./main.js",
+  "type":"commonjs"
+}

test/parallel/test-get-package-json.js

@@ -137,3 +137,11 @@ const pkgType = 'module'; // a non-default value
   const pathToParent = fixtures.path('packages/nested/package.json');
   assert.strictEqual(parentPkg.path, pathToParent);
 }
+
+{ // Can require via package.json
+  const pathToMod = fixtures.path('packages/cjs-main-no-index/other.js');
+  // require() falls back to package.json values like "main" to resolve when there is no index
+  const answer = require(pathToMod);
+
+  assert.strictEqual(answer, 43);
+}