test: add coverage (#58)

Author: gr2m

.gitignore

@@ -1,2 +1,3 @@
-node_modules/
 .env
+coverage
+node_modules/

lib/main.js

@@ -100,6 +100,7 @@ export async function main(
         authorization: `bearer ${appAuthentication.token}`,
       },
     }).catch((error) => {
+      /* c8 ignore next */
       if (error.status !== 404) throw error;
 
       // https://docs.github.com/rest/apps/apps?apiVersion=2022-11-28#get-a-user-installation-for-the-authenticated-app
@@ -122,7 +123,7 @@ export async function main(
   core.setSecret(authentication.token);
 
   core.setOutput("token", authentication.token);
-  
+
   // Make token accessible to post function (so we can invalidate it)
   if (!skipTokenRevoke) {
     core.saveState("token", authentication.token);

main.js

@@ -33,6 +33,7 @@ main(
   }),
   skipTokenRevoke
 ).catch((error) => {
+  /* c8 ignore next 3 */
   console.error(error);
   core.setFailed(error.message);
 });