1 files changed, 80 insertions, 0 deletions
diff --git a/scripts/linters/contiguous_use_block.rb b/scripts/linters/contiguous_use_block.rb
new file mode 100644
index 0000000..bce9e32
--- /dev/null
+++ b/scripts/linters/contiguous_use_block.rb
@@ -0,0 +1,80 @@
+def contiguous_use_block(root_dir)
+  pattern = root_dir.join('crates', '**', '*.rs').to_s
+  errors = Dir.glob(pattern).sort.flat_map do |path|
+    relative = Pathname.new(path).relative_path_from(root_dir).to_s
+    find_split_use_block(path, relative)
+  end
+
+  return true if errors.empty?
+
+  puts 'Found blank lines splitting the leading `use` block into sections.'
+  puts 'All `use` statements at the top of the file must be contiguous (no blank lines between them):'
+  errors.each do |err|
+    puts "  #{err}"
+  end
+  false
+end
+
+USE_START_RE = /\A(?:pub(?:\([^)]*\))?\s+)?use\b/
+
+def find_split_use_block(path, relative)
+  lines = File.readlines(path)
+  errors = []
+
+  i = skip_preamble(lines)
+  return [] if i.nil?
+
+  loop do
+    i = consume_use_statement(lines, i)
+    break if i >= lines.length
+
+    blanks = []
+    j = i
+    while j < lines.length
+      stripped = lines[j].strip
+      if stripped.empty?
+        blanks << j
+        j += 1
+      elsif stripped.start_with?('//') || stripped.start_with?('#[')
+        j += 1
+      else
+        break
+      end
+    end
+
+    if j < lines.length && lines[j].strip =~ USE_START_RE
+      blanks.each do |bi|
+        errors << "#{relative}:#{bi + 1}: blank line splits the leading `use` block"
+      end
+      i = j
+    else
+      break
+    end
+  end
+
+  errors
+end
+
+def skip_preamble(lines)
+  lines.each_with_index do |raw, idx|
+    stripped = raw.strip
+    return idx if stripped =~ USE_START_RE
+    next if stripped.empty? || stripped.start_with?('//') || stripped.start_with?('#![') || stripped.start_with?('#[')
+
+    return nil
+  end
+  nil
+end
+
+def consume_use_statement(lines, start_idx)
+  brace_depth = 0
+  i = start_idx
+  while i < lines.length
+    line = lines[i]
+    brace_depth += line.count('{') - line.count('}')
+    done = brace_depth <= 0 && line.rstrip.end_with?(';')
+    i += 1
+    return i if done
+  end
+  i
+end