Fix the cy.once typings (#4788)

* Fix the cy.once typings

* C -> c


Co-authored-by: Zach Bloomquist <github@chary.us>

cli/types/index.d.ts

@@ -327,6 +327,12 @@ declare namespace Cypress {
      */
     on: Actions
 
+    /**
+     * These events come from Cypress as it issues commands and reacts to their state. These are all useful to listen to for debugging purposes.
+     * @see https://on.cypress.io/catalog-of-events#App-Events
+     */
+    once: Actions
+
     /**
      * These events come from Cypress as it issues commands and reacts to their state. These are all useful to listen to for debugging purposes.
      * @see https://on.cypress.io/catalog-of-events#App-Events
@@ -934,6 +940,12 @@ declare namespace Cypress {
      */
     on: Actions
 
+    /**
+     * These events come from Cypress as it issues commands and reacts to their state. These are all useful to listen to for debugging purposes.
+     * @see https://on.cypress.io/catalog-of-events#App-Events
+     */
+    once: Actions
+
     /**
      * These events come from Cypress as it issues commands and reacts to their state. These are all useful to listen to for debugging purposes.
      * @see https://on.cypress.io/catalog-of-events#App-Events

cli/types/tests/cypress-tests.ts

@@ -246,6 +246,18 @@ namespace CypressOnTests {
   })
 }
 
+namespace CypressOnceTests {
+  Cypress.once('uncaught:exception', (error, runnable) => {
+    error // $ExpectType Error
+    runnable // $ExpectType IRunnable
+  })
+
+  cy.once('uncaught:exception', (error, runnable) => {
+    error // $ExpectType Error
+    runnable // $ExpectType IRunnable
+  })
+}
+
 namespace CypressOffTests {
   Cypress.off('uncaught:exception', (error, runnable) => {
     error // $ExpectType Error