fix: enrich OAuth token error messages for BullMQ job visibility

Compose descriptive err.message at error creation in OAuth provider
classes so that BullMQ failedReason includes provider name, grant type,
HTTP status, and provider error response instead of just "Token request
failed".

Author: andris9

lib/oauth/gmail.js

@@ -1,7 +1,7 @@
 'use strict';
 
 const packageData = require('../../package.json');
-const { formatPartialSecretKey, structuredClone, fetchAgent, retryAgent } = require('../tools');
+const { formatPartialSecretKey, structuredClone, fetchAgent, retryAgent, formatTokenError } = require('../tools');
 const crypto = require('crypto');
 
 const { fetch: fetchCmd } = require('undici');
@@ -342,6 +342,7 @@ class GmailOauth {
                 // ignore
             }
 
+            err.message = formatTokenError(this.provider, err.tokenRequest);
             throw err;
         }
 
@@ -460,6 +461,7 @@ class GmailOauth {
             } catch (e) {
                 // ignore
             }
+            err.message = formatTokenError(this.provider, err.tokenRequest);
             throw err;
         }
 

lib/oauth/mail-ru.js

@@ -2,7 +2,7 @@
 
 const packageData = require('../../package.json');
 const { fetch: fetchCmd } = require('undici');
-const { formatPartialSecretKey, structuredClone, fetchAgent, retryAgent } = require('../tools');
+const { formatPartialSecretKey, structuredClone, fetchAgent, retryAgent, formatTokenError } = require('../tools');
 
 const MAIL_RU_SCOPES = ['userinfo', 'mail.imap'];
 
@@ -169,6 +169,7 @@ class MailRuOauth {
             } catch (e) {
                 // ignore
             }
+            err.message = formatTokenError(this.provider, err.tokenRequest);
             throw err;
         }
 
@@ -253,6 +254,7 @@ class MailRuOauth {
             } catch (e) {
                 // ignore
             }
+            err.message = formatTokenError(this.provider, err.tokenRequest);
             throw err;
         }
 

lib/oauth/outlook.js

@@ -1,7 +1,7 @@
 'use strict';
 
 const packageData = require('../../package.json');
-const { formatPartialSecretKey, structuredClone, fetchAgent, retryAgent } = require('../tools');
+const { formatPartialSecretKey, structuredClone, fetchAgent, retryAgent, formatTokenError } = require('../tools');
 
 const { fetch: fetchCmd } = require('undici');
 
@@ -324,6 +324,7 @@ class OutlookOauth {
             } catch (e) {
                 // ignore
             }
+            err.message = formatTokenError(this.provider, err.tokenRequest);
             throw err;
         }
 
@@ -424,6 +425,7 @@ class OutlookOauth {
             } catch (e) {
                 // ignore
             }
+            err.message = formatTokenError(this.provider, err.tokenRequest);
             throw err;
         }
 

lib/schemas.js

@@ -1106,7 +1106,9 @@ const licenseSchema = Joi.object({
 }).label('LicenseInfo');
 
 const lastErrorSchema = Joi.object({
-    response: Joi.string().example('Token request failed').description('Human-readable error message'),
+    response: Joi.string()
+        .example('Token request failed for gmail (refresh_token, HTTP 400): invalid_grant - Token has been expired or revoked.')
+        .description('Human-readable error message'),
     serverResponseCode: Joi.string().example('OauthRenewError').description('Error code or classification'),
     tokenRequest: Joi.object({
         grant: Joi.string()

lib/tools.js

@@ -77,6 +77,22 @@ class LRUCache extends Map {
 
 const regexCache = new LRUCache(1000);
 
+function formatTokenError(provider, tokenRequest) {
+    let parts = [`Token request failed for ${provider}`];
+    if (tokenRequest) {
+        let detail = `${tokenRequest.grant || 'unknown'}, HTTP ${tokenRequest.status || '?'}`;
+        parts[0] += ` (${detail})`;
+        if (tokenRequest.response) {
+            let resp = tokenRequest.response;
+            let errorParts = [resp.error, resp.error_description].filter(Boolean);
+            if (errorParts.length) {
+                parts.push(errorParts.join(' - '));
+            }
+        }
+    }
+    return parts.join(': ');
+}
+
 module.exports = {
     /**
      * Helper function to set specific bit in a buffer
@@ -1785,7 +1801,9 @@ MFkwEwYHKoZIzj0CAQYIKoZIzj0DAQcDQgAEV3QUiYsp13nD9suD1/ZkEXnuMoSg
 
     LRUCache,
 
-    normalizeHashKeys
+    normalizeHashKeys,
+
+    formatTokenError
 };
 
 function msgpackDecode(buf) {