Error on deprecated compat keys (#2210)

Until we have a representation for discouraged features, we should treat
using deprecated BCD keys as an error.

This also silences the compat key tag warning, which isn't very useful
right now.

Co-authored-by: Florian Scholz <[email protected]>

scripts/dist.ts

@@ -201,7 +201,7 @@ function toDist(sourcePath: string): YAML.Document {
   if (source.compat_features) {
     source.compat_features.sort();
     if (isDeepStrictEqual(source.compat_features, taggedCompatFeatures)) {
-      logger.warn(
+      logger.silly(
         `${id}: compat_features override matches tags in @mdn/browser-compat-data. Consider deleting the compat_features override.`,
       );
     }
@@ -234,9 +234,18 @@ function toDist(sourcePath: string): YAML.Document {
   });
 
   if (computedStatus.discouraged) {
-    logger.warn(
-      `${id}: contains at least one deprecated compat feature and can never be Baseline. Was this intentional?`,
-    );
+    const isDraft: boolean = source.draft_date ?? false;
+
+    if (!source.draft_date) {
+      logger.error(
+        `${id}: contains at least one deprecated compat feature and can never be Baseline. This is forbidden for published features.`,
+      );
+      exitStatus = 1;
+    } else {
+      logger.warn(
+        `${id}: draft contains at least one deprecated compat feature and can never be Baseline. Was this intentional?`,
+      );
+    }
   }
 
   computedStatus = JSON.parse(computedStatus.toJSON());