Syntax: Remove unused variables or mark them as such

.standard_todo.yml

@@ -13,7 +13,6 @@ ignore:
   - Style/IdenticalConditionalBranches
 - lib/csvlint/csvw/property_checker.rb:
   - Performance/InefficientHashSearch
-  - Lint/UselessAssignment
   - Naming/VariableName
   - Style/SlicingWithRange
   - Security/Open
@@ -24,18 +23,16 @@ ignore:
   - Naming/VariableName
 - lib/csvlint/schema.rb:
   - Security/Open
-  - Lint/UselessAssignment
   - Style/SlicingWithRange
 - lib/csvlint/validate.rb:
-  - Lint/UselessAssignment
   - Performance/Count
   - Lint/BooleanSymbol
   - Naming/VariableName
   - Security/Open
   - Lint/NonLocalExitFromIterator
-- spec/validator_spec.rb:
-  - Lint/UselessAssignment
 - lib/csvlint/schema.rb:
   - Lint/UselessRescue
 - lib/csvlint/validate.rb:
   -  Lint/UselessRescue
+- lib/csvlint/cli.rb:
+  - Style/SafeNavigation

lib/csvlint/csvw/property_checker.rb

@@ -286,7 +286,7 @@ def column_reference_property(type)
           if value.instance_of? Hash
             if value["@id"]
               raise Csvlint::Csvw::MetadataError.new("datatype.@id"), "datatype @id must not be the id of a built-in datatype (#{value["@id"]})" if BUILT_IN_DATATYPES.values.include?(value["@id"])
-              v, w, t = PROPERTIES["@id"].call(value["@id"], base_url, lang)
+              _, w, _ = PROPERTIES["@id"].call(value["@id"], base_url, lang)
               unless w.nil?
                 warnings << w
                 value.delete("@id")
@@ -422,7 +422,7 @@ def column_reference_property(type)
                   elsif p == "url"
                   elsif p == "titles"
                   else
-                    v, warning, type = check_property(p, v, base_url, lang)
+                    _, warning, type = check_property(p, v, base_url, lang)
                     if type != :transformation && !(warning.nil? || warning.empty?)
                       value.delete(p)
                       warnings << :invalid_property unless type == :transformation
@@ -555,7 +555,7 @@ def column_reference_property(type)
             warnings = []
             value.each do |p, v|
               if ["resource", "schemaReference", "columnReference"].include? p
-                v, warning, type = check_property(p, v, base_url, lang)
+                v, warning, _ = check_property(p, v, base_url, lang)
                 if warning.nil? || warning.empty?
                   value[p] = v
                 else

lib/csvlint/schema.rb

@@ -48,7 +48,7 @@ def load_from_string(uri, string, output_errors = true)
         else
           Schema.from_json_table(uri, json)
         end
-      rescue TypeError => e
+      rescue TypeError
         # NO IDEA what this was even trying to do - SP 20160526
       rescue Csvlint::Csvw::MetadataError => e
         raise e
@@ -88,7 +88,7 @@ def validate_row(values, row = nil, all_errors = [], source_url = nil, validate
 
       fields.each_with_index do |field, i|
         value = values[i] || ""
-        result = field.validate_column(value, row, i + 1, all_errors)
+        field.validate_column(value, row, i + 1, all_errors)
         @errors += fields[i].errors
         @warnings += fields[i].warnings
       end

lib/csvlint/validate.rb

@@ -157,21 +157,20 @@ def parse_line(line)
         # If it's not a full line, then prepare to add it to the beginning of the next chunk
         @leading = line
       end
-    rescue ArgumentError => ae
+    rescue ArgumentError
       build_errors(:invalid_encoding, :structure, @current_line, nil, @current_line) unless @reported_invalid_encoding
       @current_line += 1
       @reported_invalid_encoding = true
     end
 
     def validate_line(input = nil, index = nil)
       @input = input
-      single_col = false
       line = index.present? ? index : 0
       @encoding = input.encoding.to_s
       report_line_breaks(line)
       parse_contents(input, line)
       @lambda&.call(self)
-    rescue ArgumentError => ae
+    rescue ArgumentError
       build_errors(:invalid_encoding, :structure, @current_line, nil, index) unless @reported_invalid_encoding
       @reported_invalid_encoding = true
     end
@@ -205,7 +204,7 @@ def parse_contents(stream, line = nil)
           if @schema
             @schema.validate_row(row, current_line, all_errors, @source, @validate)
             @errors += @schema.errors
-            all_errors += @schema.errors
+            @schema.errors
             @warnings += @schema.warnings
           elsif !row.empty? && row.size != @expected_columns
             build_errors(:ragged_rows, :structure, current_line, nil, stream.to_s)
@@ -277,7 +276,6 @@ def validate_metadata
               if schema.tables[@source_url]
                 @schema = schema
               else
-                warn_if_unsuccessful = true
                 build_warnings(:schema_mismatch, :context, nil, nil, @source_url, schema)
               end
             end

spec/validator_spec.rb

@@ -573,14 +573,14 @@
     it "should call a lambda for each line" do
       @count = 0
       mylambda = lambda { |row| @count += 1 }
-      validator = Csvlint::Validator.new(File.new(File.join(File.dirname(__FILE__), "..", "features", "fixtures", "valid.csv")), {}, nil, {lambda: mylambda})
+      Csvlint::Validator.new(File.new(File.join(File.dirname(__FILE__), "..", "features", "fixtures", "valid.csv")), {}, nil, {lambda: mylambda})
       expect(@count).to eq(3)
     end
 
     it "reports back the status of each line" do
       @results = []
       mylambda = lambda { |row| @results << row.current_line }
-      validator = Csvlint::Validator.new(File.new(File.join(File.dirname(__FILE__), "..", "features", "fixtures", "valid.csv")), {}, nil, {lambda: mylambda})
+      Csvlint::Validator.new(File.new(File.join(File.dirname(__FILE__), "..", "features", "fixtures", "valid.csv")), {}, nil, {lambda: mylambda})
       expect(@results.count).to eq(3)
       expect(@results[0]).to eq(1)
       expect(@results[1]).to eq(2)