revert best-effort naming scheme in preference of all-or-nothing

Author: arlyon

typify-impl/src/enums.rs

@@ -618,9 +618,7 @@ impl TypeSpace {
             .reduce(|a, b| get_common_prefix(&a, &b))
             .unwrap_or_else(String::new);
 
-        // Store seen, un-stripped names here. Any item for which their
-        // name appears more than once, ALL the items with that clashing
-        // name will be converted to the `VariantN` scheme.
+        // Store seen, un-stripped names here.
         let duplicate_names = variant_names
             .iter()
             .cloned()
@@ -636,25 +634,29 @@ impl TypeSpace {
         // Prune the common prefixes from all variant names. If this
         // results in any of them being empty, we don't use these names.
         //
-        // Fall back to VariantN if the variant name cannot be derived from
+        // Fall back to VariantN if ALL variant names cannot be derived from
         // the schema.
         let variant_names = variant_names
-            .into_iter()
-            .enumerate()
-            .map(|(idx, var_name)| {
+            .iter()
+            .map(|var_name| {
                 match var_name {
                     None => None,
-                    var_name => {
-                        var_name.filter(|var_name| !duplicate_names.contains(var_name.as_str()))
-                    }
+                    var_name => var_name
+                        .as_ref()
+                        .filter(|var_name| !duplicate_names.contains(var_name.as_str())),
                 }
                 .map(|var_name| var_name[common_prefix.len()..].to_string())
                 .filter(|var_name| !var_name.is_empty())
                 .map(|var_name| var_name.to_string())
-                // Fall back to `VariantN` naming.
-                .unwrap_or_else(|| format!("Variant{}", idx))
             })
-            .collect::<Vec<_>>();
+            .collect::<Option<Vec<_>>>()
+            .unwrap_or_else(|| {
+                variant_names
+                    .iter()
+                    .enumerate()
+                    .map(|(idx, _)| format!("Variant{idx}"))
+                    .collect()
+            });
 
         // Gather the variant details along with its name.
         let variant_details = subschemas