fix: rethrow if the Chai property is invalid, closes #36

cypress/e2e/alias.cy.js

@@ -0,0 +1,31 @@
+/// <reference types="cypress" />
+// @ts-check
+
+import '../../src'
+
+describe('aliases', () => {
+  it('has an existing alias', () => {
+    cy.wrap(42).as('answer')
+    cy.get('@answer')
+      .if('exist')
+      .log('alias exists')
+      .then(cy.spy().as('if'))
+      .else()
+      .then(cy.spy().as('else'))
+    cy.get('@if').should('have.been.called')
+    cy.get('@else').should('not.have.been.called')
+  })
+
+  // SKIP: https://github.com/bahmutov/cypress-if/issues/35
+  it.skip('has no alias', () => {
+    // notice there is no alias with the name "answer"
+    cy.get('@answer')
+      .if('exist')
+      .log('alias exists')
+      .then(cy.spy().as('if'))
+      .else()
+      .then(cy.spy().as('else'))
+    cy.get('@if').should('have.been.called')
+    cy.get('@else').should('not.have.been.called')
+  })
+})

src/index.js

@@ -102,6 +102,9 @@ Cypress.Commands.add(
         } catch (e) {
           console.error(e)
           assertionsPassed = false
+          if (e.message.includes('Invalid Chai property')) {
+            throw e
+          }
         }
       }
     }