fix(auth): allow trailing slash for start urls

Might fix cases for some users reporting that the auth screen is not accepting their start url. May or may not fix #5412

Author: hayemaxi

packages/core/src/login/webview/vue/login.vue

@@ -286,7 +286,7 @@ type Stage = 'START' | 'SSO_FORM' | 'CONNECTED' | 'AUTHENTICATING' | 'AWS_PROFIL
 
 function validateSsoUrlFormat(url: string) {
     const regex =
-        /^(https?:\/\/(.+)\.awsapps\.com\/start|https?:\/\/identitycenter\.amazonaws\.com\/ssoins-[\da-zA-Z]{16})$/
+        /^(https?:\/\/(.+)\.awsapps\.com\/start|https?:\/\/identitycenter\.amazonaws\.com\/ssoins-[\da-zA-Z]{16})\/?$/
     return regex.test(url)
 }
 
@@ -484,7 +484,7 @@ export default defineComponent({
             if (this.startUrl && !validateSsoUrlFormat(this.startUrl)) {
                 this.startUrlError =
                     'URLs must start with http:// or https://. Example: https://d-xxxxxxxxxx.awsapps.com/start'
-            } else if (this.startUrl && this.existingStartUrls.some(url => url === this.startUrl)) {
+            } else if (this.startUrl && this.existingStartUrls.some((url) => url === this.startUrl)) {
                 this.startUrlError =
                     'A connection for this start URL already exists. Sign out before creating a new one.'
             } else {
@@ -520,7 +520,7 @@ export default defineComponent({
             // to reuse connections in AWS Toolkit & Amazon Q
             const sharedConnections = await client.fetchConnections()
             sharedConnections
-                ?.filter(c => !this.existingStartUrls.includes(c.startUrl))
+                ?.filter((c) => !this.existingStartUrls.includes(c.startUrl))
                 .forEach((connection, index) => {
                     this.importedLogins.push({
                         id: LoginOption.IMPORTED_LOGINS + index,
@@ -535,7 +535,7 @@ export default defineComponent({
             this.$forceUpdate()
         },
         async updateExistingStartUrls() {
-            this.existingStartUrls = (await client.listSsoConnections()).map(conn => conn.startUrl)
+            this.existingStartUrls = (await client.listSsoConnections()).map((conn) => conn.startUrl)
         },
         async getDefaultStartUrl() {
             return await client.getDefaultStartUrl()