From a0528ca84a90ba83fd99c54b1ded855cdb6e1c08 Mon Sep 17 00:00:00 2001
From: Edd Yerburgh <edward.yerburgh@gmail.com>
Date: Sun, 23 Dec 2018 12:10:44 +0000
Subject: [PATCH] fix: improve filter typing (#1077)

---
 packages/test-utils/types/index.d.ts      | 16 +++++++++++-----
 packages/test-utils/types/test/wrapper.ts |  6 +++++-
 2 files changed, 16 insertions(+), 6 deletions(-)

diff --git a/packages/test-utils/types/index.d.ts b/packages/test-utils/types/index.d.ts
index b81c4cc7d..43cc3ff04 100644
--- a/packages/test-utils/types/index.d.ts
+++ b/packages/test-utils/types/index.d.ts
@@ -113,11 +113,17 @@ export interface Wrapper<V extends Vue | null> extends BaseWrapper {
 }
 
 export interface WrapperArray<V extends Vue> extends BaseWrapper {
-  readonly length: number
-  readonly wrappers: Array<Wrapper<V>>
-
-  at (index: number): Wrapper<V>
-  filter (predicate: Function): WrapperArray<Vue>
+  readonly length: number;
+  readonly wrappers: Array<Wrapper<V>>;
+
+  at(index: number): Wrapper<V>;
+  filter(
+    predicate: (
+      value: Wrapper<V>,
+      index: number,
+      array: Wrapper<V>[]
+    ) => any
+  ): WrapperArray<Vue>;
 }
 
 interface WrapperOptions {
diff --git a/packages/test-utils/types/test/wrapper.ts b/packages/test-utils/types/test/wrapper.ts
index 222030e16..c5f2607db 100644
--- a/packages/test-utils/types/test/wrapper.ts
+++ b/packages/test-utils/types/test/wrapper.ts
@@ -79,7 +79,11 @@ wrapper.attributes('foo')
  */
 let num: number = array.length
 found = array.at(1)
-array = array.filter((a: any) => a === true)
+array = array.filter((w, i, arr) => {
+  i + 2
+  arr.length
+  return w.is('div')
+})
 
 let createdWrapper = createWrapper(new Vue().$mount())
 createdWrapper.text()