add chainable 'be.inViewport'

apps/app/test/cypress/support/assertions.ts

@@ -0,0 +1,21 @@
+// from https://github.com/cypress-io/cypress/issues/877#issuecomment-538708750
+const isInViewport = (_chai) => {
+  function assertIsInViewport() {
+
+    const subject = this._obj;
+
+    const bottom = Cypress.config("viewportWidth");
+    const rect = subject[0].getBoundingClientRect();
+
+    this.assert(
+      rect.top < bottom && rect.bottom < bottom,
+      "expected #{this} to be in viewport",
+      "expected #{this} to not be in viewport",
+      this._obj
+    )
+  }
+
+  _chai.Assertion.addMethod('inViewport', assertIsInViewport)
+};
+
+chai.use(isInViewport);

apps/app/test/cypress/support/index.ts

@@ -14,6 +14,7 @@
 // ***********************************************************
 
 // Import commands.js using ES2015 syntax:
+import './assertions'
 import './commands'
 import './screenshot'