setup monorepo

jest/custom-matchers.ts

@@ -0,0 +1,31 @@
+// Assuming requestAnimationFrame is roughly 60 frames per second
+const frame = 1000 / 60
+
+const formatter = new Intl.NumberFormat('en')
+
+expect.extend({
+  toBeWithinRenderFrame(actual, expected) {
+    const min = expected - frame
+    const max = expected + frame
+
+    const pass = actual >= min && actual <= max
+
+    if (pass) {
+      return {
+        message: () =>
+          `expected ${actual} not to be within range of a frame ${formatter.format(
+            min
+          )} - ${formatter.format(max)}`,
+        pass: true,
+      }
+    } else {
+      return {
+        message: () =>
+          `expected ${actual} to be within range of a frame ${formatter.format(
+            min
+          )} - ${formatter.format(max)}`,
+        pass: false,
+      }
+    }
+  },
+})