fritter

Small object programming/Object oriented exercise checker.

This product extends tamada/9rules. The superior points of fritter than 9rules are as follows.

• Simplify the class relationships from 9rules.
  • In the case of 9rules, it becomes to complicated relationships among classes to satisfy the 9rules itself.
  • Then, fritter prioritizes the understandability of the source codes even if to not satisfy the rules of itself.
• Introduce more rules, and ease to add more rules.
  • This is the side effect of the above point.
  • To introduce the new rule, we provide only two classes which are subclasses of Validator and ValidatorService.
• Ease to customize the parameters for validators.
  • All parameters are read from configuration files.
  • The configuration files are given by --level option or --config option. fritter defines the parameters by json formatted config file also level.
• Enable to select the output formats.
  • fritter provides json, xml, and markdown format as result.
• Thread supports.
  • fritter uses the threads by user requests for each analyzing target.

Description

The book titled 'The ThoughtWorks Anthology: Essays on Software Technology and Innovation' are published. Chapter 6 in the book introduces object calisthenics for better software design. The rules shown in the book are as follows.

1. Use 1 level of indentation per method (indent_level), DONE
2. Do not use the else keyword (no_else), DONE
3. Wrap all primitives and strings (primitive_wrapping), DONE
4. Use only 1 dot per line (one_dot_per_line), DONE
5. Do not abbreviate (no_abbrev),
6. Keep all entities small,
   • 50 lines in a source file (lines_of_class), DONE
   • 3 lines in a method (lines_of_method), and DONE
   • 10 classses in a package (classes_in_package).
7. Do not use any classes with more than 2 instance variables (field_count), DONE
8. Use first-class collections (first_class_collection), and DONE
9. Do not use any getters/setters/properties (no_accessor) DONE

Unfortunately, to confirm obeying the rules is by a human eye. Therefore, this tool was developed to validate the rules automatically by analyzing given Java source codes. By the way, this tool is programed to obey above rules.

Additional rules

The following rules are the additional rules for more analysis.

10. Do not use any methods with more than 2 local variables (local_variable_count), DONE
11. Do not use static method except main method (no_static_method), DONE
12. Do not create an array (no_new_array), DONE
13. Do not use System.exit (no_system_exit) except main method, DONE
14. Do not use \n in the printf formatter (no_return_code_in_printf), and DONE
15. Do not use only single character in the variable name, except loop control variables (single_character_name). DONE

Usage

Usage: fritter [-hinstV] [-c=CONFIG] [-f=FORMAT] [-l=LEVEL]
               SOURCE_FILEs|SOURCE_DIRs...
Small object programming checker.
      SOURCE_FILEs|SOURCE_DIRs...
                            Java source files and/or directories containing
                              Java source files.
  -c, --config=CONFIG       specifies the configuration file.
  -f, --format=FORMAT       specifies the resultant format. Default is json.
                            Available values: json, markdown, yaml, and xml
  -h, --help                Show this help message and exit.
  -i, --no-validator-info   does not show the validator information for
                              analyses.
  -l, --level=LEVEL         specifies the strict level. Default is default.
                            Available values: strict, general, rough, and
                              default.
  -n, --no-summary          does not show the summary of analysis.
  -s, --show-no-violated-files
                            shows file names with no violations.
  -t, --with-threads        use threads for validations.
  -V, --version             Print version information and exit.

Config format

The format of config file must be JSON, like as follows.

{
  "name": "default",
  "validators": [
    "indent_level",
    "no_else",
    "primitive_wrapping",
    "dot_count_per_line",
    "no_abbrev",
    "lines_of_class",
    "lines_of_method",
    "classes_in_package",
    "field_count",
    "first_class_collection",
    "no_accessor",
    "variable_count",
    "no_static_method",
    "no_new_array",
    "no_system_exit",
    "no_return_code_in_printf",
    "single_character_name"
  ],
  "parameters": {
    "indent_level": 1,
    "dot_count_per_line": 1,
    "lines_of_class": 50,
    "lines_of_method": 3,
    "classes_in_package": 10,
    "field_count": 2,
    "variable_count": 2
  }
}

Result example

Json

The following json is validating src/test/resources/projects/examples/HelloWorld.java with no options, and formatted with jq command.

{
   "date": "2021-02-01T23:37:08.966582",
   "validators": [
      "indent_level",
      "no_else",
      "primitive_wrapping",
      "dot_count_per_line",
      "lines_of_class",
      "lines_of_method",
      "field_count",
      "first_class_collection",
      "no_accessor",
      "no_static_method",
      "no_new_array",
      "no_system_exit",
      "no_return_code_in_printf",
      "single_character_name"
   ],
   "results": [
      {
         "base": "src/test/resources/projects/examples/HelloWorld.java",
         "violations": [
            {
               "file": "",
               "messages": [
                  {
                     "line": 10,
                     "key": "lines_of_method",
                     "message": "lines of method is 4, more than 3"
                  },
                  {
                     "line": 19,
                     "key": "lines_of_method",
                     "message": "lines of method is 4, more than 3"
                  },
                  {
                     "line": 15,
                     "key": "no_accessor",
                     "message": "getMessage: no getter method"
                  },
                  {
                     "line": 2,
                     "key": "no_static_method",
                     "message": "violatedMethod: no static method except main method"
                  },
                  {
                     "line": 12,
                     "key": "no_system_exit",
                     "message": "no System.exit except main method"
                  },
                  {
                     "line": 11,
                     "key": "no_return_code_in_printf",
                     "message": "no '\n', use '%n' in printf"
                  }
               ]
            }
         ]
      }
   ],
   "summary": {
      "violated-files": 1,
      "total-files": 1,
      "violated-file-count": 6
   }
}

Xml

The following xml is validating src/test/resources/projects/examples/Primes.java with -f xml options, and formatted with xmllint command (xmllint --format -).

<?xml version="1.0"?>
<fritter>
   <validators>
      <validator>indent_level</validator>
      <validator>no_else</validator>
      <validator>primitive_wrapping</validator>
      <validator>dot_count_per_line</validator>
      <validator>lines_of_class</validator>
      <validator>lines_of_method</validator>
      <validator>field_count</validator>
      <validator>first_class_collection</validator>
      <validator>no_accessor</validator>
      <validator>no_static_method</validator>
      <validator>no_new_array</validator>
      <validator>no_system_exit</validator>
      <validator>no_return_code_in_printf</validator>
      <validator>single_character_name</validator>
   </validators>
   <results>
      <result>
         <base-directory>src/test/resources/projects/examples/Primes.java</base-directory>
         <files>
            <file>
               <file-name/>
               <violations>
                  <violation>
                     <validator-type>indent_level</validator-type>
                     <location>
                        <line-number>17</line-number>
                     </location>
                     <message>print: indent level is 2, more than 1</message>
                  </violation>
                  <violation>
                     <validator-type>indent_level</validator-type>
                     <location>
                        <line-number>29</line-number>
                     </location>
                     <message>sieves: indent level is 2, more than 1</message>
                  </violation>
                  <violation>
                     <validator-type>no_else</validator-type>
                     <location>
                        <line-number>51</line-number>
                     </location>
                     <message>no else statement</message>
                  </violation>
                  <violation>
                     <validator-type>lines_of_class</validator-type>
                     <location>
                        <line-number>3</line-number>
                     </location>
                     <message>lines of class is 55, more than 50</message>
                  </violation>
                  <violation>
                     <validator-type>lines_of_method</validator-type>
                     <location>
                        <line-number>4</line-number>
                     </location>
                     <message>lines of method is 5, more than 3</message>
                  </violation>
                  <violation>
                     <validator-type>lines_of_method</validator-type>
                     <location>
                        <line-number>10</line-number>
                     </location>
                     <message>lines of method is 15, more than 3</message>
                  </violation>
                  <violation>
                     <validator-type>lines_of_method</validator-type>
                     <location>
                        <line-number>26</line-number>
                     </location>
                     <message>lines of method is 8, more than 3</message>
                  </violation>
                  <violation>
                     <validator-type>lines_of_method</validator-type>
                     <location>
                        <line-number>35</line-number>
                     </location>
                     <message>lines of method is 5, more than 3</message>
                  </violation>
                  <violation>
                     <validator-type>lines_of_method</validator-type>
                     <location>
                        <line-number>41</line-number>
                     </location>
                     <message>lines of method is 5, more than 3</message>
                  </violation>
                  <violation>
                     <validator-type>lines_of_method</validator-type>
                     <location>
                        <line-number>47</line-number>
                     </location>
                     <message>lines of method is 6, more than 3</message>
                  </violation>
                  <violation>
                     <validator-type>no_new_array</validator-type>
                     <location>
                        <line-number>42</line-number>
                     </location>
                     <message>do not use array, use List instead</message>
                  </violation>
               </violations>
            </file>
         </files>
      </result>
   </results>
   <summary>
      <violated-file-count>1</violated-file-count>
      <target-file-count>1</target-file-count>
      <violation-count>11</violation-count>
   </summary>
</fritter>

Markdown

The following markdown is validating src/test/resources/projects/examples/StatsValues.java with -f markdown options.

# fritter results

Date: 2021-02-01T23:47:02.609847

## Validators

* indent_level
* no_else
* primitive_wrapping
* dot_count_per_line
* lines_of_class
* lines_of_method
* field_count
* first_class_collection
* no_accessor
* no_static_method
* no_new_array
* no_system_exit
* no_return_code_in_printf
* single_character_name

## Results

### src/test/resources/projects/examples/StatsValues.java

#### 

##### Violations

* indent_level (line: 23)
    * print: indent level is 2, more than 1
* lines_of_method (line: 13)
    * lines of method is 5, more than 3
* lines_of_method (line: 19)
    * lines of method is 9, more than 3
* lines_of_method (line: 29)
    * lines of method is 5, more than 3
* lines_of_method (line: 35)
    * lines of method is 4, more than 3
* lines_of_method (line: 40)
    * lines of method is 5, more than 3
* field_count (lines: 9, 10, 11)
    * field count is 3, more than 2
* first_class_collection (lines: 9, 10, 11)
    * not first class collection

## Summary

* violated files: 1
* total files: 1
* violated file count: 8