fix(auth): malformed SSO cache didn't prompt reauth

Problem:

When we loaded sso cache from disk, we would only invalidate (leading to a reauth prompt)
if the cache file was missing.

But if the cache file was present, though its content was malformed, we would incorrectly
treat it as recoverable by throwing instead of returning undefined.

Solution:

If we detect a SyntaxError treat it as non-recoverable, meaning it will trigger a reauth.
Also added some code to validate the content of the SSO cache we loaded from disk to ensure
it is what we expected.

Signed-off-by: nkomonen-amazon <[email protected]>

packages/core/src/auth/sso/cache.ts

@@ -10,11 +10,12 @@ import { getLogger } from '../../shared/logger/logger'
 import fs from '../../shared/fs/fs'
 import { createDiskCache, KeyedCache, mapCache } from '../../shared/utilities/cacheUtils'
 import { stripUndefined } from '../../shared/utilities/collectionUtils'
-import { hasProps, selectFrom } from '../../shared/utilities/tsUtils'
+import { getMissingProps, hasProps, selectFrom } from '../../shared/utilities/tsUtils'
 import { SsoToken, ClientRegistration } from './model'
 import { DevSettings } from '../../shared/settings'
 import { onceChanged } from '../../shared/utilities/functionUtils'
 import globals from '../../shared/extensionGlobals'
+import { ToolkitError } from '../../shared'
 
 interface RegistrationKey {
     readonly startUrl: string
@@ -92,6 +93,12 @@ export function getTokenCache(directory = getCacheDir()): KeyedCache<SsoAccess>
 
         stripUndefined(token)
 
+        // Validate data is not missing.
+        const missingProps = getMissingProps(token, 'accessToken', 'refreshToken')
+        if (missingProps.length > 0) {
+            throw new ToolkitError(`SSO cache data unexpectedly missing props: ${JSON.stringify(missingProps)}`)
+        }
+
         return {
             token,
             registration,

packages/core/src/shared/utilities/cacheUtils.ts

@@ -116,10 +116,23 @@ export function createDiskCache<V, K>(
                 log('loaded', key)
                 return result
             } catch (error) {
+                // Non-recoverable errors mean there is no usable data.
+                // Recoverable errors mean we can possibly use the data for something like
+                // an SSO token refresh, or to just retry.
+                // Returning undefined implies non-recoverable.
+
+                // -- Non-recoverable Errors --
                 if (isFileNotFoundError(error)) {
                     log('read failed (file not found)', key)
                     return
                 }
+                if (error instanceof SyntaxError) {
+                    // file content was malformed or empty
+                    log(`read failed (invalid JSON)`, key)
+                    return
+                }
+
+                // -- Recoverable Errors --
                 log(`read failed ${error}`, key)
                 throw createDiskCacheError(error, 'LOAD', target, key)
             }