log a confirmation message after a successful logout (#1131)

* log a confirmation message after a successful logout

* fix test

Author: Fil

src/observableApiAuth.ts

@@ -118,7 +118,9 @@ export async function loginInner(
 }
 
 export async function logout(effects = defaultEffects) {
+  const {logger} = effects;
   await effects.setObservableApiKey(null);
+  logger.log(`You are now logged out of ${OBSERVABLE_UI_ORIGIN.hostname}.`);
 }
 
 export async function whoami(effects = defaultEffects) {

test/observableApiAuth-test.ts

@@ -72,7 +72,7 @@ describe("logout command", () => {
     await logout(effects);
     assert.equal(effects.observableApiKey, null);
     assert.equal(await effects.setApiKeyDeferred.promise, undefined);
-    effects.logger.assertExactLogs([]);
+    effects.logger.assertExactLogs([/^You are now logged out of/]);
   });
 });