cleanup: move internal npmAddScriptSync function (#150)

and finish removing `lib/utils`

with zero test updates since this change should *not* affect
any actual behavior

Author: Chris Brody

lib/lib.js

@@ -10,13 +10,12 @@ const execaDefault = require('execa');
 // default fs object
 const fsExtra = require('fs-extra');
 
+const jsonfile = require('jsonfile');
+
 // Internal imports:
 
 const normalizedOptions = require('./normalized-options');
 
-// FUTURE TBD remaining module in utils to be factored out:
-const { npmAddScriptSync } = require('./utils');
-
 // Imports from templates
 
 const templates = require('../templates');
@@ -46,6 +45,22 @@ const renderTemplateIfValid = (fs, root, template, templateArgs) => {
   );
 };
 
+// FUTURE TBD make this asynchronous and possibly more functional:
+const npmAddScriptSync = (packageJsonPath, script, fs) => {
+  try {
+    var packageJson = jsonfile.readFileSync(packageJsonPath, { fs });
+    if (!packageJson.scripts) packageJson.scripts = {};
+    packageJson.scripts[script.key] = script.value;
+    jsonfile.writeFileSync(packageJsonPath, packageJson, { fs, spaces: 2 });
+  } catch (e) {
+    if (/ENOENT.*package.json/.test(e.message)) {
+      throw new Error(`The package.json at path: ${packageJsonPath} does not exist.`);
+    } else {
+      throw e;
+    }
+  }
+};
+
 const generateWithNormalizedOptions = ({
   name,
   prefix,