install: fix checking for optional dep

larsgw · larsgw · commit c81df49bf071 · 2018-10-07T22:40:16.000+02:00
See https://npm.community/t/2569
diff --git a/lib/install/is-only-optional.js b/lib/install/is-only-optional.js
@@ -10,6 +10,7 @@ function isOptional (node, seen) {
   if (seen.has(node) || node.requiredBy.length === 0) {
     return false
   }
+  seen = new Set(seen)
   seen.add(node)
   const swOptional = node.fromShrinkwrap && node.package._optional
   return node.requiredBy.every(function (req) {

Original file line number	Diff line number	Diff line change
`@@ -10,6 +10,7 @@ function isOptional (node, seen) {`
`10`	`10`	`if (seen.has(node) \|\| node.requiredBy.length === 0) {`
`11`	`11`	`return false`
`12`	`12`	`}`
	`13`	`+ seen = new Set(seen)`
`13`	`14`	`seen.add(node)`
`14`	`15`	`const swOptional = node.fromShrinkwrap && node.package._optional`
`15`	`16`	`return node.requiredBy.every(function (req) {`