time-to-botec/js/node_modules/@stdlib/streams/node/debug/lib/main.js

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/**
* @license Apache-2.0
*
* Copyright (c) 2018 The Stdlib Authors.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
'use strict';
// MODULES //
var InspectStream = require( './../../../node/inspect' );
var isFunction = require( '@stdlib/assert/is-function' );
var isBuffer = require( '@stdlib/assert/is-buffer' );
var copy = require( '@stdlib/utils/copy' );
var inherit = require( '@stdlib/utils/inherit' );
var debug = require( './debug.js' );
var DEFAULTS = require( './defaults.json' );
var NAMESPACE = require( './namespace.js' );
var validate = require( './validate.js' );
var logger = require( './logger.js' );
// MAIN //
/**
* Debug stream constructor.
*
* @constructor
* @param {Options} [options] - stream options
* @param {string} [options.name] - debug namespace
* @param {boolean} [options.objectMode=false] - specifies whether the stream should operate in object mode
* @param {NonNegativeNumber} [options.highWaterMark] - specifies the `Buffer` level for when `write()` starts returning `false`
* @param {boolean} [options.allowHalfOpen=false] - specifies whether the stream should remain open even if one side ends
* @param {boolean} [options.readableObjectMode=false] - specifies whether the readable side should be in object mode
* @param {Callback} [clbk] - callback to invoke upon receiving data
* @throws {TypeError} must provide valid options
* @throws {TypeError} must a valid callback argument
* @returns {DebugStream} debug stream
*
* @example
* var stream = new DebugStream({
* 'name': 'my-stream'
* });
*
* stream.write( 'a' );
* stream.write( 'b' );
* stream.write( 'c' );
* stream.end();
*/
function DebugStream( options, clbk ) {
var opts;
var name;
var log;
var err;
var cb;
if ( !(this instanceof DebugStream) ) {
if ( arguments.length > 1 ) {
return new DebugStream( options, clbk );
}
if ( arguments.length === 1 ) {
return new DebugStream( options );
}
return new DebugStream();
}
opts = copy( DEFAULTS );
if ( arguments.length > 1 ) {
if ( !isFunction( clbk ) ) {
throw new TypeError( 'invalid argument. Callback argument must be a function. Value: `' + clbk + '`.' );
}
cb = clbk;
err = validate( opts, options );
} else if ( arguments.length ) {
if ( isFunction( options ) ) {
cb = options;
} else {
err = validate( opts, options );
}
}
if ( err ) {
throw err;
}
if ( opts.name ) {
name = NAMESPACE + ':' + opts.name;
} else {
name = NAMESPACE;
}
log = logger( name );
debug( 'Creating a transform stream configured with the following options: %s.', JSON.stringify( opts ) );
InspectStream.call( this, opts, inspect );
return this;
/**
* Callback invoked upon receiving a new chunk.
*
* @private
* @param {*} chunk - received chunk
* @param {NonNegativeInteger} idx - chunk index
* @returns {void}
*/
function inspect( chunk, idx ) {
if ( cb ) {
debug( 'Received a new chunk. Chunk: %s. Index: %d.', chunk.toString(), idx );
return cb( log, chunk, idx );
}
if ( isBuffer( chunk ) ) {
chunk = chunk.toString();
}
chunk = JSON.stringify( chunk );
debug( 'Received a new chunk. Chunk: %s. Index: %d.', chunk, idx );
log( 'Chunk: %s. Index: %d.', chunk, idx );
}
}
/*
* Inherit from the `InspectStream` prototype.
*/
inherit( DebugStream, InspectStream );
// EXPORTS //
module.exports = DebugStream;