es-usage-rate

Analyze JavaScript and output usage rate of each syntax.

What's is

The Analyzer parse code and process AST.

AST is defined by estree/estree: The ESTree Spec.

1. parse(Code) => AST
2. map(AST) => Nodes
3. reduce(Nodes) => Nodes
4. format(Nodes) => result!

Installation

npm install es-usage-rate

Usage

CLI

$ es-usage-rate "src/**/*.js"

[Options]

    --formatter formatter name - default: "line-by-line",
    --mapper: mapper name - default: "line-by-line",
    --reducer: reducer name - default: "identity"

[stdin]

$ cat file.js | es-usage-rate

Use-case

Use this with distribution.

$ es-usage-rate "src/*.js" | distribution
                Key|Ct  (Pct)    Histogram
         Identifier|842 (35.47%) ▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
   MemberExpression|221  (9.31%) ▬▬▬▬▬▬▬▬▬▬▬▬▬
     CallExpression|176  (7.41%) ▬▬▬▬▬▬▬▬▬▬
        CommentLine|128  (5.39%) ▬▬▬▬▬▬▬
      StringLiteral|126  (5.31%) ▬▬▬▬▬▬▬
 VariableDeclarator| 95  (4.00%) ▬▬▬▬▬▬
VariableDeclaration| 95  (4.00%) ▬▬▬▬▬▬
     BlockStatement| 78  (3.29%) ▬▬▬▬▬
       CommentBlock| 74  (3.12%) ▬▬▬▬▬
ExpressionStatement| 69  (2.91%) ▬▬▬▬
     ObjectProperty| 63  (2.65%) ▬▬▬▬
     ThisExpression| 62  (2.61%) ▬▬▬▬
    TemplateElement| 35  (1.47%) ▬▬
    ReturnStatement| 32  (1.35%) ▬▬
   ObjectExpression| 26  (1.10%) ▬▬

Filter by ES6 node

Reducer

--reducer es6 filter by ES6 node

$ es-usage-rate --reducer es6 "src/**/*.js" | distribution --char=ba
                      Key|Ct  (Pct)    Histogram
VariableDeclaration:const|156 (44.07%) ▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
          TemplateElement| 75 (21.19%) ▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬▬
  VariableDeclaration:let| 32  (9.04%) ▬▬▬▬▬▬▬▬▬
          TemplateLiteral| 32  (9.04%) ▬▬▬▬▬▬▬▬▬
  ArrowFunctionExpression| 29  (8.19%) ▬▬▬▬▬▬▬▬
        AssignmentPattern| 12  (3.39%) ▬▬▬▬
            ObjectPattern|  6  (1.69%) ▬▬
         ClassDeclaration|  6  (1.69%) ▬▬
                ClassBody|  6  (1.69%) ▬▬

Formatter

--formatter json-by-file output results of count by group.

es-usage-rate --formatter json-by-file --reducer es6 "src/**/*.js"
[{"@file":"src/cli/cli.js","ImportDeclaration":2,"ImportSpecifier":2,"ImportDefaultSpecifier":1,"ExportNamedDeclaration":2,"VariableDeclaration:const":1},{"@file":"src/es-usage-rate.js","ImportDeclaration":5,"ImportNamespaceSpecifier":1,"ImportSpecifier":4,"VariableDeclaration:const":11,"ArrowFunctionExpression":3,"ExportNamedDeclaration":2,"AssignmentPattern":2},{"@file":"src/formatter.js","ImportDeclaration":2,"ImportDefaultSpecifier":2,"ExportNamedDeclaration":1,"VariableDeclaration:const":1,"ArrowFunctionExpression":1},{"@file":"src/formatters/json-by-all.js","ImportDeclaration":1,"ImportSpecifier":1,"VariableDeclaration:const":4,"ArrowFunctionExpression":3,"VariableDeclaration:let":4,"ExportDefaultDeclaration":1,"ObjectPattern":1},{"@file":"src/formatters/json-by-file.js","ImportDeclaration":1,"ImportSpecifier":1,"ExportDefaultDeclaration":1,"ArrowFunctionExpression":1,"VariableDeclaration:const":1,"ObjectPattern":1},{"@file":"src/formatters/line-by-line.js","ExportDefaultDeclaration":1,"VariableDeclaration:let":1,"ArrowFunctionExpression":1,"VariableDeclaration:const":1,"ObjectPattern":1},{"@file":"src/mapper.js","ImportDeclaration":2,"ImportDefaultSpecifier":2,"ExportNamedDeclaration":1,"VariableDeclaration:const":1,"ArrowFunctionExpression":1},{"@file":"src/mappers/line-by-line.js","ImportDeclaration":2,"ImportDefaultSpecifier":1,"ImportSpecifier":1,"ExportDefaultDeclaration":1,"VariableDeclaration:const":2},{"@file":"src/parser.js","ExportNamedDeclaration":1},{"@file":"src/reducer.js","ImportDeclaration":2,"ImportDefaultSpecifier":2,"ExportNamedDeclaration":1},{"@file":"src/reducers/es6.js","VariableDeclaration:const":1,"ExportDefaultDeclaration":1,"ArrowFunctionExpression":2},{"@file":"src/reducers/identity.js","ExportDefaultDeclaration":1},{"@file":"src

--formatter json-by-all output single object that sum of count by group.

es-usage-rate --formatter json-by-all --reducer es6 "src/**/*.js"
{"@file":"src/","ImportDeclaration":17,"ImportSpecifier":9,"ImportDefaultSpecifier":8,"ExportNamedDeclaration":9,"VariableDeclaration:const":25,"ImportNamespaceSpecifier":1,"ArrowFunctionExpression":12,"AssignmentPattern":2,"VariableDeclaration:let":5,"ExportDefaultDeclaration":7,"ObjectPattern":3,"TemplateLiteral":1,"TemplateElement":3}

Tests

npm test

Contributing

1. Fork it!
2. Create your feature branch: git checkout -b my-new-feature
3. Commit your changes: git commit -am 'Add some feature'
4. Push to the branch: git push origin my-new-feature
5. Submit a pull request :D

License

MIT