E2E Framework: fix empty array check in RestAPIClient. (#74741)

* packages/calypso-e2e/src/rest-api-client.ts
- fix empty array check

* packages/calypso-e2e/src/rest-api-client.ts
- fix another instance of comparison

* packages/calypso-e2e/src/rest-api-client.ts
- fix if logic.
- add output.
- add comments.

* packages/calypso-e2e/src/rest-api-client.ts
- truthy check

* packages/calypso-e2e/src/test/rest-api-client.invites.test.ts
- fix test

packages/calypso-e2e/src/rest-api-client.ts

@@ -354,15 +354,20 @@ export class RestAPIClient {
 			params
 		);
 
+		// This handles API errors such as `unauthorized`.
 		if ( response.hasOwnProperty( 'error' ) ) {
 			throw new Error(
 				`${ ( response as ErrorResponse ).error }: ${ ( response as ErrorResponse ).message }`
 			);
 		}
 
-		if ( response.errors === [] ) {
-			console.log( response );
-			throw new Error( `Failed to create invite: ${ response.errors }` );
+		// This handles "errors" relating to the invite itself and can be an array.
+		// For instance, if a user tries to invite itself, or invite an already added user.
+		if ( response.errors.length ) {
+			for ( const err of response.errors ) {
+				console.error( `${ err.code }: ${ err.message }` );
+			}
+			throw new Error( `Failed to create invite due to ${ response.errors.length } errors.` );
 		}
 
 		return response;
@@ -1035,7 +1040,7 @@ export class RestAPIClient {
 		if ( response.hasOwnProperty( 'error' ) && response.error === 'not_found' ) {
 			console.info( `Widget ${ widgetID } not found.` );
 			return;
-		} else if ( response === [] ) {
+		} else if ( response.length === 0 ) {
 			console.info( `Deleted widget ${ widgetID }.` );
 		} else if ( response.id === widgetID ) {
 			console.info( `Deactivated widget ${ widgetID }` );

packages/calypso-e2e/src/test/rest-api-client.invites.test.ts

@@ -115,7 +115,7 @@ describe( 'RestAPIClient: createInvite', function () {
 		expect( response.errors.length ).toBe( 0 );
 	} );
 
-	test( 'Invite cannot be created', async function () {
+	test( 'Invite is rejected due to existing user email', async function () {
 		const testSuccessfulEmails = [ '[email protected]' ];
 		const testFailedEmails = [ '[email protected]' ];
 		const role = 'Editor' as Roles;
@@ -126,14 +126,11 @@ describe( 'RestAPIClient: createInvite', function () {
 
 		nock( requestURL.origin ).post( requestURL.pathname ).reply( 200, testResponse );
 
-		const response: NewInviteResponse = await restAPIClient.createInvite( siteID, {
-			email: testSuccessfulEmails.concat( testFailedEmails ),
-			role: role,
-		} );
-		expect( response.sent ).toBeInstanceOf( Array );
-		expect( response.sent.length ).toBe( 1 );
-		expect( response.sent ).toEqual( testSuccessfulEmails );
-		expect( response.errors.length ).toBe( 1 );
-		expect( response.errors ).toEqual( testFailedEmails );
+		await expect( () =>
+			restAPIClient.createInvite( siteID, {
+				email: testSuccessfulEmails.concat( testFailedEmails ),
+				role: role,
+			} )
+		).rejects.toThrowError();
 	} );
 } );