From 9b7b778221c5f0d0c111e4f604bccfa291c982ed Mon Sep 17 00:00:00 2001
From: stdll00 <16006732+stdll00@users.noreply.github.com>
Date: Thu, 8 Dec 2022 22:26:50 +0900
Subject: [PATCH] fix: improve error message when missing tags[browser]

---
 web/web.bzl | 7 +++++--
 1 file changed, 5 insertions(+), 2 deletions(-)

diff --git a/web/web.bzl b/web/web.bzl
index e50ab367..edf3ff8d 100644
--- a/web/web.bzl
+++ b/web/web.bzl
@@ -110,8 +110,11 @@ def _get_kwargs(browser, in_kwargs):
                 out_kwargs[k] = v["default"]
         else:
             out_kwargs[k] = v
-
-    if not out_kwargs["tags"]:
+    if "tags" not in out_kwargs:
+        fail("expeted \"default\" or \"{browser}\" dict key in tags argument.".format(
+            browser = browser,
+        ))
+    elif not out_kwargs["tags"]:
         out_kwargs["tags"] = ["browser:" + browser]
     else:
         out_kwargs["tags"] = ["browser:" + browser] + out_kwargs["tags"]