feat: retain unknown features from command line and before.js

lib/run-questionnaire.js

@@ -15,6 +15,16 @@ function isSame(arr1, arr2) {
   return true;
 }
 
+function minusSet(list1, list2) {
+  const left = [];
+  for (const x of list1) {
+    if (list2.indexOf(x) === -1 && left.indexOf(x) === -1) {
+      left.push(x);
+    }
+  }
+  return left;
+}
+
 // Get user provided predefinedProperties, preselectedFeatures, go through all the questions,
 // Output a cleaned up features.
 //
@@ -86,7 +96,13 @@ async function run(questions, {
     await ask(questions[i]);
   }
 
-  return [{...predefinedProperties, ...properties}, pickedFeatures, notDefaultFeatures];
+  const unknownFeatures = minusSet(preselectedFeatures, pickedFeatures);
+
+  return [
+    {...predefinedProperties, ...properties},
+    [...pickedFeatures, ...unknownFeatures],
+    [...notDefaultFeatures, ...unknownFeatures]
+  ];
 }
 
 async function textPrompt(question, {predefinedProperties, unattended, _debug}) {

test/run-questionnaire.spec.js

@@ -278,16 +278,16 @@ test('run runs through questionnaire with preselectedFeatures and predefinedProp
   ]);
 });
 
-test('run runs through questionnaire with preselectedFeatures and predefinedProperties, and keeps unknown properties', async t => {
+test('run runs through questionnaire with preselectedFeatures and predefinedProperties, and keeps unknown properties and selection', async t => {
   const result = await run(questions, {
-    preselectedFeatures: ['postcss'],
+    preselectedFeatures: ['postcss', 'lorem', 'abc', 'lorem'],
     predefinedProperties: {name: 'new-app', foo: 'bar'},
     _debug: [2]
   });
   t.deepEqual(result, [
     {name: 'new-app', foo: 'bar'},
-    ['dumber', 'postcss'],
-    ['dumber', 'postcss']
+    ['dumber', 'postcss', 'lorem', 'abc'],
+    ['dumber', 'postcss', 'lorem', 'abc']
   ]);
 });