fix: merge values array -> prevent duplicates

README.md

@@ -268,6 +268,7 @@ Returns **[string](https://developer.mozilla.org/docs/Web/JavaScript/Reference/G
 ## merge
 
 merge from b into a
+When a and b are arrays of values only the none duplaces are appendend to a
 
 ### Parameters
 
@@ -283,7 +284,7 @@ genreates a new object tree by removing sensible values like credentials from it
 ### Parameters
 
 -   `object` **[Object](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object)** 
--   `toBeRemoved`   (optional, default `key=>key.match(/pass|auth|key|user/)`)
+-   `toBeRemoved`   (optional, default `key=>key.match(/pass|auth|key|user|secret/)`)
 
 Returns **[Object](https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object)** object tree free of sensible data
 

src/util.mjs

@@ -8,6 +8,7 @@ export function createValue(value) {
 
 /**
  * merge from b into a
+ * When a and b are arrays of values only the none duplaces are appendend to a
  * @param {any} a
  * @param {any} b
  * @return {any} merged b into a
@@ -16,7 +17,7 @@ export function merge(a, b) {
   if (b !== undefined) {
     if (Array.isArray(a)) {
       if (Array.isArray(b)) {
-        return [...a, ...b];
+        return [...a,...a.filter(x => !b.includes(x))]
       }
       return [...a, b];
     }

tests/merge-test.mjs

@@ -13,3 +13,8 @@ test("merge", async t =>
       a2: { b1: 7 }
     }
   ));
+
+test("merge array", async t =>
+  t.deepEqual(await expand({ x: ["a", "b"] }, { default: { x: ["a", "b"] } }), {
+    x: ["a", "b"]
+  }));