text: /**
  * @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 resolve = require( 'path' ).resolve;
  var exec = require( 'child_process' ).exec;
  var tape = require( 'tape' );
  var IS_BROWSER = require( '@stdlib/assert-is-browser' );
  var IS_WINDOWS = require( '@stdlib/assert-is-windows' );
  var EXEC_PATH = require( '@stdlib/process-exec-path' );
  var isnan = require( '@stdlib/math-base-assert-is-nan' );
  var beta = require( '@stdlib/random-base-beta' ).factory;
  var readFileSync = require( '@stdlib/fs-read-file' ).sync;
  var existsSync = require( '@stdlib/fs-exists' ).sync;
  var unlinkSync = require( '@stdlib/fs-unlink' ).sync;
  var Uint32Array = require( '@stdlib/array-uint32' );
  var Uint8Array = require( '@stdlib/array-uint8' );
  var gcopy = require( '@stdlib/blas-base-gcopy' );
  var replace = require( '@stdlib/string-replace' );
  
  
  // VARIABLES //
  
  var fpath = resolve( __dirname, '..', 'bin', 'cli' );
  var opts = {
  	'skip': IS_BROWSER || IS_WINDOWS
  };
  
  
  // FIXTURES //
  
  var PKG_VERSION = require( './../package.json' ).version;
  
  
  // TESTS //
  
  tape( 'command-line interface', function test( t ) {
  	t.ok( true, __filename );
  	t.end();
  });
  
  tape( 'when invoked with a `--help` flag, the command-line interface prints the help text to `stderr`', opts, function test( t ) {
  	var expected;
  	var cmd;
  
  	expected = readFileSync( resolve( __dirname, '..', 'docs', 'usage.txt' ), {
  		'encoding': 'utf8'
  	});
  	cmd = [
  		EXEC_PATH,
  		fpath,
  		'--help'
  	];
  
  	exec( cmd.join( ' ' ), done );
  
  	function done( error, stdout, stderr ) {
  		if ( error ) {
  			t.fail( error.message );
  		} else {
  			t.strictEqual( stdout.toString(), '', 'does not print to `stdout`' );
  			t.strictEqual( stderr.toString(), expected+'\n', 'expected value' );
  		}
  		t.end();
  	}
  });
  
  tape( 'when invoked with a `-h` flag, the command-line interface prints the help text to `stderr`', opts, function test( t ) {
  	var expected;
  	var cmd;
  
  	expected = readFileSync( resolve( __dirname, '..', 'docs', 'usage.txt' ), {
  		'encoding': 'utf8'
  	});
  	cmd = [
  		EXEC_PATH,
  		fpath,
  		'-h'
  	];
  
  	exec( cmd.join( ' ' ), done );
  
  	function done( error, stdout, stderr ) {
  		if ( error ) {
  			t.fail( error.message );
  		} else {
  			t.strictEqual( stdout.toString(), '', 'does not print to `stdout`' );
  			t.strictEqual( stderr.toString(), expected+'\n', 'expected value' );
  		}
  		t.end();
  	}
  });
  
  tape( 'when invoked with a `--version` flag, the command-line interface prints the version to `stderr`', opts, function test( t ) {
  	var cmd = [
  		EXEC_PATH,
  		fpath,
  		'--version'
  	];
  
  	exec( cmd.join( ' ' ), done );
  
  	function done( error, stdout, stderr ) {
  		if ( error ) {
  			t.fail( error.message );
  		} else {
  			t.strictEqual( stdout.toString(), '', 'does not print to `stdout`' );
  			t.strictEqual( stderr.toString(), PKG_VERSION+'\n', 'expected value' );
  		}
  		t.end();
  	}
  });
  
  tape( 'when invoked with a `-V` flag, the command-line interface prints the version to `stderr`', opts, function test( t ) {
  	var cmd = [
  		EXEC_PATH,
  		fpath,
  		'-V'
  	];
  
  	exec( cmd.join( ' ' ), done );
  
  	function done( error, stdout, stderr ) {
  		if ( error ) {
  			t.fail( error.message );
  		} else {
  			t.strictEqual( stdout.toString(), '', 'does not print to `stdout`' );
  			t.strictEqual( stderr.toString(), PKG_VERSION+'\n', 'expected value' );
  		}
  		t.end();
  	}
  });
  
  tape( 'if provided insufficient arguments, the command-line interface prints an error and sets a non-zero exit code (none)', opts, function test( t ) {
  	var cmd = [
  		EXEC_PATH,
  		fpath
  	];
  
  	exec( cmd.join( ' ' ), done );
  
  	function done( error, stdout, stderr ) {
  		if ( error ) {
  			t.pass( error.message );
  			t.strictEqual( error.code, 1, 'expected exit code' );
  		} else {
  			t.fail( 'should error' );
  		}
  		t.strictEqual( stdout.toString(), '', 'does not print to `stdout`' );
  		t.strictEqual( stderr.toString().length > 0, true, 'prints to `stderr`' );
  		t.end();
  	}
  });
  
  tape( 'if provided insufficient arguments, the command-line interface prints an error and sets a non-zero exit code (one)', opts, function test( t ) {
  	var cmd = [
  		EXEC_PATH,
  		fpath,
  		'2.0'
  	];
  
  	exec( cmd.join( ' ' ), done );
  
  	function done( error, stdout, stderr ) {
  		if ( error ) {
  			t.pass( error.message );
  			t.strictEqual( error.code, 1, 'expected exit code' );
  		} else {
  			t.fail( 'should error' );
  		}
  		t.strictEqual( stdout.toString(), '', 'does not print to `stdout`' );
  		t.strictEqual( stderr.toString().length > 0, true, 'prints to `stderr`' );
  		t.end();
  	}
  });
  
  tape( 'the command-line interface supports specifying the number of generated pseudorandom numbers', opts, function test( t ) {
  	var cmd = [
  		EXEC_PATH,
  		fpath,
  		'2.0',
  		'5.0',
  		'--iter 10'
  	];
  
  	exec( cmd.join( ' ' ), done );
  
  	function done( error, stdout, stderr ) {
  		var results;
  		var v;
  		var i;
  		if ( error ) {
  			t.fail( error.message );
  		} else {
  			t.strictEqual( stderr.toString(), '', 'does not print to `stderr`' );
  
  			results = stdout.toString();
  			results = results.split( '\n' );
  
  			// 10 numbers + trailing newline:
  			t.strictEqual( results.length, 11, 'has expected length' );
  			for ( i = 0; i < results.length-1; i++ ) {
  				v = parseFloat( results[ i ] );
  				t.strictEqual( typeof v, 'number', 'has expected type' );
  				t.strictEqual( isnan( v ), false, 'is not NaN' );
  			}
  		}
  		t.end();
  	}
  });
  
  tape( 'the command-line interface supports specifying the pseudorandom number generator seed', opts, function test( t ) {
  	var rand;
  	var cmd;
  
  	cmd = [
  		EXEC_PATH,
  		fpath,
  		'2.0',
  		'5.0',
  		'--iter 10',
  		'--seed 12345'
  	];
  
  	// Note: we assume that the underlying generator is the following PRNG...
  	rand = beta( 2.0, 5.0, {
  		'seed': 12345
  	});
  
  	exec( cmd.join( ' ' ), done );
  
  	function done( error, stdout, stderr ) {
  		var results;
  		var v;
  		var i;
  		if ( error ) {
  			t.fail( error.message );
  		} else {
  			t.strictEqual( stderr.toString(), '', 'does not print to `stderr`' );
  
  			results = stdout.toString();
  			results = results.split( '\n' );
  
  			// 10 numbers + trailing newline:
  			t.strictEqual( results.length, 11, 'has expected length' );
  			for ( i = 0; i < results.length-1; i++ ) {
  				v = parseFloat( results[ i ] );
  				t.strictEqual( v, rand(), 'prints expected value' );
  			}
  		}
  		t.end();
  	}
  });
  
  tape( 'the command-line interface supports specifying a custom delimiter', opts, function test( t ) {
  	var cmd = [
  		EXEC_PATH,
  		fpath,
  		'2.0',
  		'5.0',
  		'--iter 10',
  		'--sep aba'
  	];
  
  	exec( cmd.join( ' ' ), done );
  
  	function done( error, stdout, stderr ) {
  		var results;
  		var v;
  		var i;
  		if ( error ) {
  			t.fail( error.message );
  		} else {
  			t.strictEqual( stderr.toString(), '', 'does not print to `stderr`' );
  
  			results = stdout.toString();
  			results = results.split( '\n' );
  
  			// Only trailing newline:
  			t.strictEqual( results.length, 2, 'has expected length' );
  
  			results = results[ 0 ].split( 'aba' );
  			t.strictEqual( results.length, 10, 'has expected length' );
  			for ( i = 0; i < results.length-1; i++ ) {
  				v = parseFloat( results[ i ] );
  				t.strictEqual( typeof v, 'number', 'has expected type' );
  				t.strictEqual( isnan( v ), false, 'is not NaN' );
  			}
  		}
  		t.end();
  	}
  });
  
  tape( 'the command-line interface supports specifying a pseudorandom number generator state', opts, function test( t ) {
  	var state;
  	var spath;
  	var rand;
  	var cmd;
  	var len;
  
  	spath = resolve( __dirname, 'fixtures', 'state.txt' );
  	state = readFileSync( spath );
  
  	cmd = [
  		EXEC_PATH,
  		fpath,
  		'2.0',
  		'5.0',
  		'--iter 10',
  		'--state "'+spath+'"'
  	];
  
  	// Explicitly copy the `Buffer`, as, in older Node.js versions, `Buffer` is not a typed array:
  	len = state.length;
  	state = gcopy( len, state, 1, new Uint8Array( len ), 1 );
  	state = new Uint32Array( state.buffer, state.byteOffset, len/Uint32Array.BYTES_PER_ELEMENT ); // eslint-disable-line max-len
  
  	// Note: we assume that the underlying generator is the following PRNG...
  	rand = beta( 2.0, 5.0, {
  		'state': state
  	});
  
  	exec( cmd.join( ' ' ), done );
  
  	function done( error, stdout, stderr ) {
  		var results;
  		var v;
  		var i;
  		if ( error ) {
  			t.fail( error.message );
  		} else {
  			t.strictEqual( stderr.toString(), '', 'does not print to `stderr`' );
  
  			results = stdout.toString();
  			results = results.split( '\n' );
  
  			// 10 numbers + trailing newline:
  			t.strictEqual( results.length, 11, 'has expected length' );
  			for ( i = 0; i < results.length-1; i++ ) {
  				v = parseFloat( results[ i ] );
  				t.strictEqual( v, rand(), 'prints expected value' );
  			}
  		}
  		t.end();
  	}
  });
  
  tape( 'the command-line interface supports specifying an output file path for saving the pseudorandom number generator state upon exit', opts, function test( t ) {
  	var state;
  	var spath;
  	var rand;
  	var cmd;
  	var arr;
  	var i;
  
  	// Define an output path for a temporary file:
  	spath = resolve( __dirname, 'fixtures', 'tmp_state_snapshot.txt' );
  
  	// Ensure that the temporary file does not already exist:
  	if ( existsSync( spath ) ) {
  		t.fail( 'temporary file should not exist: '+spath );
  		return t.end();
  	}
  
  	cmd = [
  		EXEC_PATH,
  		fpath,
  		'2.0',
  		'5.0',
  		'--seed 12345',
  		'--iter 10',
  		'--snapshot "'+spath+'"'
  	];
  
  	// Note: we assume that the underlying generator is the following PRNG...
  	rand = beta( 2.0, 5.0, {
  		'seed': 12345
  	});
  
  	// Advance the PRNG state:
  	arr = [];
  	for ( i = 0; i < 10; i++ ) {
  		arr.push( rand() );
  	}
  
  	// Get the current PRNG state:
  	state = rand.state;
  
  	exec( cmd.join( ' ' ), done );
  
  	function done( error, stdout, stderr ) {
  		var snapshot;
  		var results;
  		var len;
  		var err;
  		var v;
  		var i;
  		if ( error ) {
  			t.fail( error.message );
  		} else {
  			t.strictEqual( stderr.toString(), '', 'does not print to `stderr`' );
  
  			results = stdout.toString();
  			results = results.split( '\n' );
  
  			// 10 numbers + trailing newline:
  			t.strictEqual( results.length, 11, 'has expected length' );
  			for ( i = 0; i < results.length-1; i++ ) {
  				v = parseFloat( results[ i ] );
  				t.strictEqual( v, arr[ i ], 'prints expected value' );
  			}
  
  			// Check that the PRNG state was written to a file:
  			t.strictEqual( existsSync( spath ), true, 'temporary snapshot file exists' );
  
  			// Verify the file contents (note: we need to explicitly copy the `Buffer`, as, in older Node.js versions, `Buffer` is not a typed array):
  			snapshot = readFileSync( spath );
  			len = snapshot.length;
  			snapshot = gcopy( len, snapshot, 1, new Uint8Array( len ), 1 );
  			snapshot = new Uint32Array( snapshot.buffer, snapshot.byteOffset, len/Uint32Array.BYTES_PER_ELEMENT ); // eslint-disable-line max-len
  
  			t.deepEqual( snapshot, state, 'file contains expected contents' );
  
  			// Remove the temporary file:
  			err = unlinkSync( spath );
  			if ( err ) {
  				t.fail( err.message );
  			}
  			t.strictEqual( existsSync( spath ), false, 'temporary snapshot file does not exist' );
  		}
  		t.end();
  	}
  });
  
  tape( 'if provided an invalid pseudorandom number generator state, the command-line interface prints an error and sets a non-zero exit code', opts, function test( t ) {
  	var spath;
  	var cmd;
  
  	spath = resolve( __dirname, 'fixtures', 'bad_state.txt' );
  
  	cmd = [
  		EXEC_PATH,
  		fpath,
  		'2.0',
  		'5.0',
  		'--iter 10',
  		'--state "'+spath+'"'
  	];
  
  	exec( cmd.join( ' ' ), done );
  
  	function done( error, stdout, stderr ) {
  		if ( error ) {
  			t.pass( error.message );
  			t.strictEqual( error.code, 1, 'expected exit code' );
  		} else {
  			t.fail( 'should error' );
  		}
  		t.strictEqual( stdout.toString(), '', 'does not print to `stdout`' );
  		t.strictEqual( stderr.toString().length > 0, true, 'prints to `stderr`' );
  		t.end();
  	}
  });
  
  tape( 'if an error is encountered when writing pseudorandom number generator state to file, the command-line interface prints an error and sets a non-zero exit code', opts, function test( t ) {
  	var script;
  	var opts;
  	var cmd;
  
  	script = readFileSync( resolve( __dirname, 'fixtures', 'write_error.js.txt' ), {
  		'encoding': 'utf8'
  	});
  
  	// Replace single quotes with double quotes:
  	script = replace( script, '\'', '"' );
  
  	cmd = [
  		EXEC_PATH,
  		'-e',
  		'\''+script+'\''
  	];
  
  	opts = {
  		'cwd': __dirname
  	};
  
  	exec( cmd.join( ' ' ), opts, done );
  
  	function done( error, stdout, stderr ) {
  		if ( error ) {
  			t.pass( error.message );
  			t.strictEqual( error.code, 1, 'expected exit code' );
  		}
  		// Pseudorandom numbers have already been written to `stdout` by the time the error is encountered...
  		t.strictEqual( stdout.toString().length > 0, true, 'prints to `stdout`' );
  		t.strictEqual( stderr.toString(), 'Error: beep\n', 'expected value' );
  		t.end();
  	}
  });
  