generate-code

The plugin exports a class that helps generate code and sourcemaps.

Installation

npm install --save generate-code

Usage

const CodeGenerator = require('generate-code');

const code = new CodeGenerator(options);

code.add('var a, b;\n');
code.addWithMapping(
  'var c;',
  { line: 1, column: 10 },
  'c'
);

const generatedCode = code.toString();

// var a, b;
// var c;

const generatedMap = code.generateMap();

// {
//   version: 3,
//   ...
// }

API

CodeGenerator

new CodeGenerator(options: Options)

• options.filename (required): filename for the sourcemap.
• options.sourceContent (required): source content for the sourcemap.
• options.sourceMap (default: true): if it is needed to generate a sourcemap.
• options.inputSourceMap (default: null): input sourcemap.

CodeGenerator#add

add(chunk: string): this

Adds a chunk of code to the generated code.

Example:

code.add('fun(1, 2);');

CodeGenerator#addWithMap

addWithMap(
  chunk: string,
  map: SourceMap,
  position?: { line: number, column: number } | number
): this

Applies the map to the existing map (shifting it according to the current position in the generated code) and then adds the chunk of code.

Third optional parameter is the position of the mappings relatively to the source. Can be a number or a { line, column } object with 0-indexed line.

Example:

const code = new CodeGenerator({
  filename: 'index.js',
  sourceContent: `var a = 10;
var b = {
  c: 1,
  d: 2
};
var c = [];`
});

code.add(`var a = 10;
var b = `);

const {
  code: generated,
  map
} = addUnderscoreToProps(`{
  c: 1,
  d: 2
}`);

code.addWithMap(
  generated,
  map,
  { line: 1, column: 8 } // where '{' is located
);
code.add(`;
var c = [];`);

console.log(code.toString());

// var a = 10;
// var b = {
//   _c: 1,
//   _d: 2,
// };

CodeGenerator#addWithMapping

addWithMapping(
  chunk: string,
  position?: { line: number, column: number } | number,
  name?: string
): this

Applies the mapping to the existing map (shifting it according to the current position in the generated code) and then adds the chunk of code.

Second optional parameter is the position of the mapping relatively to the source. Can be a number or a { line, column } object with 0-indexed line.

Third optional argument describes the mapping name.

Example:

const code = new CodeGenerator({
  filename: 'index.js',
  sourceContent: `var a = 10;
var b = {
  c: 1,
  d: 2
};
var c = [];`
});

code.add(`var a = 10;
var b = {
  `);

code.addWithMapping(
  '_c',
  { line: 2, column: 2 }, // where 'c' is located
  'c'
);

code.add(`: 1,
  `);

code.addWithMapping(
  '_d',
  { line: 3, column: 2 }, // where 'd' is located
  'd'
);

code.add(`: 2
};
var c = [];`);

console.log(code.toString());

// var a = 10;
// var b = {
//   _c: 1,
//   _d: 2,
// };

CodeGenerator#getCurrentIndent()

getCurrentIndent(): string

Returns current code indent.

Example:

const code = new CodeGenerator({
  filename: 'index.js',
  sourceContent: 'abc'
});

code.add('\na');

code.toString();         // '\na'
code.getCurrentIndent(); // ''

code.add('\n  b');

code.toString();         // '\na\n  b'
code.getCurrentIndent(); // '  '

code.add('\n\tc');

code.toString();         // '\na\n  b\n\tc'
code.getCurrentIndent(); // '\t'

CodeGenerator#toString()

toString(): string

Returns the generated code.

CodeGenerator#generateMap()

generateMap(): SourceMap

Returns the generated sourcemap.