#399

backend/app/services/post_import_previewer.rb

@@ -10,7 +10,6 @@ class PostImportPreviewer
     'tags',
     'parent_post_ids'].freeze
   FETCH_WARNING_FIELDS = ['url', 'title', 'thumbnail_base'].freeze
-  EXISTING_SKIP_WARNING = '既存投稿のためスキップします．'.freeze
   TITLE_FETCH_WARNING = 'タイトルを取得できませんでした．'.freeze
   THUMBNAIL_FETCH_WARNING = 'サムネールを取得できませんでした．'.freeze
   METADATA_FETCH_WARNING = 'メタデータを取得できませんでした．'.freeze
@@ -91,7 +90,6 @@ class PostImportPreviewer
     end
 
     if validation_errors.blank? && normal_url.present? && existing_post
-      add_field_warning!(field_warnings, 'url', EXISTING_SKIP_WARNING)
       attributes['tags'] = merged_tags(tag_sources, provenance['tags'])
       warnings_present = field_warnings.values.any?(&:present?) || base_warnings.present?
       return { source_row: row[:source_row],
@@ -113,8 +111,12 @@ class PostImportPreviewer
     if should_fetch
       clear_fetch_warnings!(field_warnings)
       metadata = metadata_for(url_for_metadata, metadata_cache)
-      apply_metadata!(attributes, provenance, tag_sources, metadata[:data])
-      apply_fetch_warnings!(field_warnings, metadata[:warnings])
+      if metadata[:validation_errors].present?
+        validation_errors.merge!(metadata[:validation_errors])
+      else
+        apply_metadata!(attributes, provenance, tag_sources, metadata[:data])
+        apply_fetch_warnings!(field_warnings, metadata[:warnings])
+      end
     end
 
     attributes['url'] = url
@@ -200,7 +202,8 @@ class PostImportPreviewer
   end
 
   def fetch_metadata url
-    return { data: { }, warnings: { 'url' => ['URL が空です．'] } } if url.blank?
+    return { data: { }, warnings: { 'url' => ['URL が空です．'] },
+             validation_errors: { } } if url.blank?
 
     data = sanitise_metadata(PostMetadataFetcher.fetch(url).stringify_keys.compact)
     warnings = { }
@@ -208,13 +211,18 @@ class PostImportPreviewer
     if data['thumbnail_base'].blank?
       add_field_warning!(warnings, 'thumbnail_base', THUMBNAIL_FETCH_WARNING)
     end
-    { data:, warnings: }
+    { data:, warnings:, validation_errors: { } }
+  rescue Preview::UrlSafety::UnsafeUrl => e
+    Rails.logger.info(
+        "post_import_metadata_fetch_unsafe_url "\
+        "#{ { error: e.class.name, message: e.message }.to_json }")
+    { data: { }, warnings: { }, validation_errors: { url: [e.message] } }
   rescue Preview::HttpFetcher::FetchFailed,
          Preview::HttpFetcher::ResponseTooLarge => e
     Rails.logger.info(
         "post_import_metadata_fetch_failure "\
         "#{ { error: e.class.name, message: e.message }.to_json }")
-    { data: { }, warnings: { 'url' => [METADATA_FETCH_WARNING] } }
+    { data: { }, warnings: { 'url' => [METADATA_FETCH_WARNING] }, validation_errors: { } }
   end
 
   def sanitise_metadata metadata
@@ -295,11 +303,16 @@ class PostImportPreviewer
 
   def safe_fetch_metadata url
     fetch_metadata(url)
+  rescue Preview::UrlSafety::UnsafeUrl => e
+    Rails.logger.info(
+        "post_import_metadata_fetch_unsafe_url "\
+        "#{ { error: e.class.name, message: e.message }.to_json }")
+    { data: { }, warnings: { }, validation_errors: { url: [e.message] } }
   rescue StandardError => e
     Rails.logger.error(
         "post_import_metadata_fetch_unexpected_failure "\
         "#{ { error: e.class.name, message: e.message }.to_json }")
-    { data: { }, warnings: { 'url' => [METADATA_FETCH_WARNING] } }
+    { data: { }, warnings: { 'url' => [METADATA_FETCH_WARNING] }, validation_errors: { } }
   end
 
   def preload_known_tags prepared_rows, fetch_metadata, metadata_cache, existing_posts, url_counts