diff --git a/app/ecs/ecs.test.js b/app/ecs/ecs.test.js
index d6e6ce0..864b27a 100644
--- a/app/ecs/ecs.test.js
+++ b/app/ecs/ecs.test.js
@@ -3,25 +3,21 @@ import {expect, test} from 'vitest';
 import Component from './component.js';
 import Ecs from './ecs.js';
 import System from './system.js';
+import {wrapComponents} from './test-helper.js';
 
-function wrapProperties(name, properties) {
-  return class WrappedComponent extends Component {
-    static componentName = name;
-    static properties = properties;
-  };
-}
+const Components = wrapComponents([
+  ['Empty', {}],
+  ['Momentum', {x: {type: 'int32'}, y: {type: 'int32'}, z: {type: 'int32'}}],
+  ['Name', {name: {type: 'string'}}],
+  ['Position', {x: {type: 'int32', defaultValue: 32}, y: {type: 'int32'}, z: {type: 'int32'}}],
+]);
 
-const Empty = wrapProperties('Empty', {});
-
-const Name = wrapProperties('Name', {
-  name: {type: 'string'},
-});
-
-const Position = wrapProperties('Position', {
-  x: {type: 'int32', defaultValue: 32},
-  y: {type: 'int32'},
-  z: {type: 'int32'},
-});
+const {
+  Empty,
+  Momentum,
+  Position,
+  Name,
+} = Components;
 
 function asyncTimesTwo(x) {
   return new Promise((resolve) => {
@@ -131,11 +127,6 @@ test('inserts components into entities', async () => {
 });
 
 test('ticks systems', async () => {
-  const Momentum = wrapProperties('Momentum', {
-    x: {type: 'int32'},
-    y: {type: 'int32'},
-    z: {type: 'int32'},
-  });
   const ecs = new Ecs({
     Components: {Momentum, Position},
     Systems: {
diff --git a/app/ecs/query.test.js b/app/ecs/query.test.js
index a18e590..d5f6a75 100644
--- a/app/ecs/query.test.js
+++ b/app/ecs/query.test.js
@@ -1,23 +1,14 @@
 import {expect, test} from 'vitest';
 
-import Ecs from './ecs';
-import Component from './component.js';
+import Ecs from './ecs.js';
+import {wrapComponents} from './test-helper.js';
 import Query from './query.js';
 
-const Components = [
+const Components = wrapComponents([
   ['A', {a: {type: 'int32', defaultValue: 64}}],
   ['B', {b: {type: 'int32', defaultValue: 32}}],
   ['C', {c: {type: 'int32'}}],
-]
-  .reduce((Components, [componentName, properties]) => {
-    return {
-      ...Components,
-      [componentName]: class extends Component {
-        static componentName = componentName;
-        static properties = properties;
-      },
-    };
-  }, {})
+]);
 
 const ecsTest = test.extend({
   ecs: async ({}, use) => {
diff --git a/app/ecs/test-helper.js b/app/ecs/test-helper.js
new file mode 100644
index 0000000..8a41f91
--- /dev/null
+++ b/app/ecs/test-helper.js
@@ -0,0 +1,14 @@
+import Component from './component.js';
+
+export function wrapComponents(Components) {
+  return Components
+    .reduce((Components, [componentName, properties]) => {
+      return {
+        ...Components,
+        [componentName]: class extends Component {
+          static componentName = componentName;
+          static properties = properties;
+        },
+      };
+    }, {})
+}
\ No newline at end of file