flow-tostring

toString

Transform stream which converts each datum to a string.

Installation

$ npm install flow-tostring

For use in the browser, use browserify.

Usage

To use the module,

var toString = require( 'flow-tostring' );

toString( [options] )

Returns a transform stream where each chunk is converted to a string. To create a new stream,

var stream = toString();

The default options are as follows:

• highWaterMark=16
• encoding=null
• allowHalfOpen=true
• objectMode=false
• decodeStrings=true

To set the options when creating a stream,

var opts = {
        'encoding': 'utf8',
        'highWaterMark': 8,
        'allowHalfOpen': false,
        'objectMode': true,
        'decodeStrings': false
    };
 
stream = toString( opts );

toString.factory( [options] )

Returns a reusable stream factory. The factory method ensures streams are configured identically by using the same set of provided options.

var opts = {
        'encoding': 'utf8',
        'highWaterMark': 8,
        'allowHalfOpen': false,
        'objectMode': true,
        'decodeStrings': false
    };
 
var factory = toString.factory( opts );
 
var streams = new Array( 10 );
 
// Create many streams configured identically but may each be independently written to...
for ( var i = 0; i < streams.length; i++ ) {
    streams[ i ] = factory();
}

toString.objectMode( [options] )

This method is a convenience function to create transform streams which always operate in objectMode. The method will always override the objectMode option in options.

var fromArray, toString;
 
fromArray = require( 'flow-from-array' ).objectMode;
toString = require( 'flow-tostring' ).objectMode;
 
fromArray( [1,2,3,4] )
    .pipe( toString() )
    .pipe( process.stdout );

Examples

var toString = require( 'flow-tostring' ),
    append = require( 'flow-append' ).objectMode,
    fromArray = require( 'flow-from-array' );
 
// Create some data...
var data = new Array( 1000 );
for ( var i = 0; i < data.length; i++ ) {
    data[ i ] = Math.random();
}
 
// Create a readable stream:
var readableStream = fromArray( data );
 
// Pipe the data:
readableStream
    .pipe( toString() )
    .pipe( append( '\n' ) )
    .pipe( process.stdout );

To run the example code from the top-level application directory,

$ node ./examples/index.js

Notes

The output (readable) stream always operates in objectMode.

When in objectMode, anything which is not a buffer or a string is coerced into being a string. Values are stringified according to the following conventions:

• undefined: "undefined"
• number: <number>.toString()
• boolean: <boolean>.toString()
• function: <function>.toString()
• array: JSON.stringify( <array> )
• object: JSON.stringify( <object> )

The only value which cannot be converted to a string is null due to the special status null has in Node.js streams.

With the exception of arrays and objects, the conventions follow the ES5 specification. arrays and objects are more conveniently stringified.

Note that the stringified values are buffered according to the encoding option. If the encoding is null (default), buffering assumes utf8 encoding.

Tests

Unit

Unit tests use the Mocha test framework with Chai assertions. To run the tests, execute the following command in the top-level application directory:

$ make test

All new feature development should have corresponding unit tests to validate correct functionality.

Test Coverage

This repository uses Istanbul as its code coverage tool. To generate a test coverage report, execute the following command in the top-level application directory:

$ make test-cov

Istanbul creates a ./reports/coverage directory. To access an HTML version of the report,

$ open reports/coverage/lcov-report/index.html

License

MIT license.

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Copyright

Copyright © 2014. Athan Reines.