diff --git a/__test__/array-merge.test.ts b/__test__/array-merge.test.ts
index e8e0321..b92f5f7 100644
--- a/__test__/array-merge.test.ts
+++ b/__test__/array-merge.test.ts
@@ -1,10 +1,7 @@
-import { VNodeData, VNodeDirective } from "vue";
+import { VNodeData } from "vue";
 import { mergeData } from "../src/index";
 
 it("should execute array merge on class, style, directive properties", () => {
-  function inserted(el: any) {
-    el.focus();
-  }
   let vd1: VNodeData = {
     class: ["a", { b: true, c: false }],
     style: ["display:block;", { color: "red", fontSize: "16px" }],
@@ -12,7 +9,6 @@ it("should execute array merge on class, style, directive properties", () => {
   let vd2: VNodeData = {
     class: ["d", { e: true, f: false }],
     style: "position:absolute;",
-    directives: [{ focus: { inserted } }],
   };
 
   let actual = mergeData(vd1, vd2);
@@ -23,7 +19,6 @@ it("should execute array merge on class, style, directive properties", () => {
       "display:block;",
       { color: "red", fontSize: "16px" },
     ],
-    directives: [{ focus: { inserted } }],
   };
 
   // Check values recursively
diff --git a/__test__/handler-merge.test.ts b/__test__/handler-merge.test.ts
index 9133f41..7ac0f29 100644
--- a/__test__/handler-merge.test.ts
+++ b/__test__/handler-merge.test.ts
@@ -1,4 +1,4 @@
-import { VNodeData, VNodeDirective } from "vue";
+import { VNodeData } from "vue";
 import { mergeData } from "../src/index";
 
 it("should not mutate original object (issue #2)", () => {
@@ -53,7 +53,7 @@ it("should set single handlers and concat multi", () => {
 
 it("should call the right-most argument first", () => {
   let first = 0;
-  let factory = n => () => {
+  let factory = (n: number) => () => {
     if (!first) {
       first = n;
     }
@@ -67,6 +67,10 @@ it("should call the right-most argument first", () => {
   );
 
   expect(Array.isArray(actual.on.click)).toBe(true);
+  if (!Array.isArray(actual.on.click)) {
+    throw new TypeError();
+  }
+
   for (const fn of actual.on.click) {
     fn();
   }
diff --git a/__test__/kitchen-sink.test.ts b/__test__/kitchen-sink.test.ts
index 0d10f2f..05cf94d 100644
--- a/__test__/kitchen-sink.test.ts
+++ b/__test__/kitchen-sink.test.ts
@@ -1,4 +1,4 @@
-import { VNodeData, VNodeDirective } from "vue";
+import { VNodeData } from "vue";
 import { mergeData } from "../src/index";
 
 it("should handle multiple arguments", () => {
@@ -28,8 +28,8 @@ it("should handle multiple arguments", () => {
 });
 
 it("should work like in the example", () => {
-  let onClick1 = e => alert("💥");
-  let onClick2 = e => alert("👍");
+  let onClick1 = () => alert("💥");
+  let onClick2 = () => alert("👍");
 
   let componentData: VNodeData = {
     staticClass: "fn-component", // concatenates all static classes
diff --git a/__test__/nullable-objects.test.ts b/__test__/nullable-objects.test.ts
index e565dcb..23fe909 100644
--- a/__test__/nullable-objects.test.ts
+++ b/__test__/nullable-objects.test.ts
@@ -1,4 +1,4 @@
-import { VNodeData, VNodeDirective } from "vue";
+import { VNodeData } from "vue";
 import { mergeData } from "../src/index";
 
 it("should handle nested nullable objects as initial state", () => {
diff --git a/__test__/reassign.test.ts b/__test__/reassign.test.ts
index f2d37e6..8492e48 100644
--- a/__test__/reassign.test.ts
+++ b/__test__/reassign.test.ts
@@ -1,4 +1,4 @@
-import { VNodeData, VNodeDirective } from "vue";
+import { VNodeData } from "vue";
 import { mergeData } from "../src/index";
 
 it("should reassign primitives", () => {
diff --git a/__test__/string-concat.test.ts b/__test__/string-concat.test.ts
index 57f959e..5ca347a 100644
--- a/__test__/string-concat.test.ts
+++ b/__test__/string-concat.test.ts
@@ -1,4 +1,4 @@
-import { VNodeData, VNodeDirective } from "vue";
+import { VNodeData } from "vue";
 import { mergeData } from "../src/index";
 
 it("should concatenate strings", () => {