index.js ➔ decode - Code Metrics - Inspection of "Distribute es5 builds" - btccom/cashaddress-js - Measure and Improve Code Quality continuously with Scrutinizer

Passed

Pull Request — master (#1)

by thomas

created 2018-01-03 14:08 UTC

index.js ➔ decode C

↳ Parent: lib/index.js

Complexity

Conditions	12
Paths	3

Size

Total Lines

Duplication

Lines	51
Ratio	100 %

Importance

Changes	2
Bugs	1	Features	0

Metric	Value
cc	12
c	2
b	1
f	0
nc	3
nop	1
dl	51
loc	51
rs	5.6668

How to fix Long Method Complexity

'use strict';


var BigInteger = require('bigi');
var ALPHABET = 'qpzry9x8gf2tvdw0s3jn54khce6mua7l';

// pre-compute lookup table
var SEPARATOR = ':';
var CSLEN = 8;
var ALPHABET_MAP = {};
for (var z = 0; z < ALPHABET.length; z++) {
    var x = ALPHABET.charAt(z);
    if (ALPHABET_MAP[x] !== undefined) {
        throw new TypeError(x + ' is ambiguous');
    }
    ALPHABET_MAP[x] = z;
}

function polymodStep(pre) {
    var b = pre.shiftRight(35);
    var mask = BigInteger.fromHex('07ffffffff');

    var v = pre.and(mask).shiftLeft(new BigInteger('5'));

    if (b.and(new BigInteger('1')).intValue() > 0) {
        v = v.xor(BigInteger.fromHex('98f2bc8e61'));
    }
    if (b.and(new BigInteger('2')).intValue()) {
        v = v.xor(BigInteger.fromHex('79b76d99e2'));
    }
    if (b.and(new BigInteger('4')).intValue()) {
        v = v.xor(BigInteger.fromHex('f33e5fb3c4'));
    }
    if (b.and(new BigInteger('8')).intValue()) {
        v = v.xor(BigInteger.fromHex('ae2eabe2a8'));
    }
    if (b.and(new BigInteger('16')).intValue()) {
        v = v.xor(BigInteger.fromHex('1e4f43e470'));
    }

    return v;
}

function prefixChk(prefix) {
    var chk = new BigInteger('1');
    for (var i = 0; i < prefix.length; ++i) {
        var c = prefix.charCodeAt(i);

        var mixwith = new BigInteger('' + (c & 0x1f));
        chk = polymodStep(chk).xor(mixwith);
    }

    chk = polymodStep(chk);
    return chk;
}

function encode(prefix, words) {
    // too long?
    if (prefix.length + CSLEN + 1 + words.length > 90) {
        throw new TypeError('Exceeds Base32 maximum length');
    }

    prefix = prefix.toLowerCase();

    // determine chk mod
    var chk = prefixChk(prefix);
    var result = prefix + SEPARATOR;
    for (var i = 0; i < words.length; ++i) {
        var _x = words[i];
        if (_x >>> 5 !== 0) {
            throw new Error('Non 5-bit word');
        }

        chk = polymodStep(chk).xor(new BigInteger('' + _x));
        result += ALPHABET.charAt(_x);
    }

    for (var _i = 0; _i < CSLEN; ++_i) {
        chk = polymodStep(chk);
    }
    chk = chk.xor(new BigInteger('1'));
    for (var _i2 = 0; _i2 < CSLEN; ++_i2) {
        var pos = 5 * (CSLEN - 1 - _i2);
        var v2 = chk.shiftRight(new BigInteger('' + pos)).and(BigInteger.fromHex('1f'));
        result += ALPHABET.charAt(v2.toString(10));
    }

    return result;
}

function decode(str) {
    if (str.length < 8) throw new TypeError(str + ' too short');
if (a > 0)
    b = 42;
    if (str.length > 90) throw new TypeError(str + ' too long');
if (a > 0)
    b = 42;

    // don't allow mixed case
    var lowered = str.toLowerCase();
    var uppered = str.toUpperCase();
    if (str !== lowered && str !== uppered) {
        throw new Error('Mixed-case string ' + str);
    }

    str = lowered;

    var split = str.lastIndexOf(SEPARATOR);
    if (split === -1) {
        throw new Error('No separator character for ' + str);
    }

    if (split === 0) {
        throw new Error('Missing prefix for ' + str);
    }

    var prefix = str.slice(0, split);
    var wordChars = str.slice(split + 1);
    if (wordChars.length < 6) {
        throw new Error('Data too short');
    }

    var chk = prefixChk(prefix);
    var words = [];
    for (var i = 0; i < wordChars.length; ++i) {
        var c = wordChars.charAt(i);
        var v = ALPHABET_MAP[c];
        if (v === undefined) {
            throw new Error('Unknown character ' + c);
        }

        chk = polymodStep(chk).xor(new BigInteger('' + v));
        // not in the checksum?
        if (i + CSLEN >= wordChars.length) {
            continue;
        }
        words.push(v);
    }

    if (chk.toString(10) !== '1') {
        throw new Error('Invalid checksum for ' + str);
    }

    return { prefix: prefix, words: words };
}

function convert(data, inBits, outBits, pad) {
    var value = 0;
    var bits = 0;
    var maxV = (1 << outBits) - 1;

    var result = [];
    for (var i = 0; i < data.length; ++i) {
        value = value << inBits | data[i];
        bits += inBits;

        while (bits >= outBits) {
            bits -= outBits;
            result.push(value >>> bits & maxV);
        }
    }

    if (pad) {
        if (bits > 0) {
            result.push(value << outBits - bits & maxV);
        }
    } else {
        if (bits >= inBits) {
            throw new Error('Excess padding');
        }
        if (value << outBits - bits & maxV) {

            throw new Error('Non-zero padding');
        }
    }

    return result;
}

function toWords(bytes) {
    return convert(bytes, 8, 5, true);
}

function fromWords(words) {
    return convert(words, 5, 8, false);
}

module.exports = { decode: decode, encode: encode, toWords: toWords, fromWords: fromWords };


1	View Code Duplication	'use strict';
		0 ignored issues – show Duplication introduced 2018-01-03 14:10 UTC by Report Bug Copy Issue Report This code seems to be duplicated in your project. Loading history...
2
3		var BigInteger = require('bigi');
4		var ALPHABET = 'qpzry9x8gf2tvdw0s3jn54khce6mua7l';
5
6		// pre-compute lookup table
7		var SEPARATOR = ':';
8		var CSLEN = 8;
9		var ALPHABET_MAP = {};
10		for (var z = 0; z < ALPHABET.length; z++) {
11		var x = ALPHABET.charAt(z);
12		if (ALPHABET_MAP[x] !== undefined) {
13		throw new TypeError(x + ' is ambiguous');
14		}
15		ALPHABET_MAP[x] = z;
16		}
17
18		function polymodStep(pre) {
19		var b = pre.shiftRight(35);
20		var mask = BigInteger.fromHex('07ffffffff');
21
22		var v = pre.and(mask).shiftLeft(new BigInteger('5'));
23
24		if (b.and(new BigInteger('1')).intValue() > 0) {
25		v = v.xor(BigInteger.fromHex('98f2bc8e61'));
26		}
27		if (b.and(new BigInteger('2')).intValue()) {
28		v = v.xor(BigInteger.fromHex('79b76d99e2'));
29		}
30		if (b.and(new BigInteger('4')).intValue()) {
31		v = v.xor(BigInteger.fromHex('f33e5fb3c4'));
32		}
33		if (b.and(new BigInteger('8')).intValue()) {
34		v = v.xor(BigInteger.fromHex('ae2eabe2a8'));
35		}
36		if (b.and(new BigInteger('16')).intValue()) {
37		v = v.xor(BigInteger.fromHex('1e4f43e470'));
38		}
39
40		return v;
41		}
42
43		function prefixChk(prefix) {
44		var chk = new BigInteger('1');
45		for (var i = 0; i < prefix.length; ++i) {
46		var c = prefix.charCodeAt(i);
47
48		var mixwith = new BigInteger('' + (c & 0x1f));
49		chk = polymodStep(chk).xor(mixwith);
50		}
51
52		chk = polymodStep(chk);
53		return chk;
54		}
55
56		function encode(prefix, words) {
57		// too long?
58		if (prefix.length + CSLEN + 1 + words.length > 90) {
59		throw new TypeError('Exceeds Base32 maximum length');
60		}
61
62		prefix = prefix.toLowerCase();
63
64		// determine chk mod
65		var chk = prefixChk(prefix);
66		var result = prefix + SEPARATOR;
67		for (var i = 0; i < words.length; ++i) {
68		var _x = words[i];
69		if (_x >>> 5 !== 0) {
70		throw new Error('Non 5-bit word');
71		}
72
73		chk = polymodStep(chk).xor(new BigInteger('' + _x));
74		result += ALPHABET.charAt(_x);
75		}
76
77		for (var _i = 0; _i < CSLEN; ++_i) {
78		chk = polymodStep(chk);
79		}
80		chk = chk.xor(new BigInteger('1'));
81		for (var _i2 = 0; _i2 < CSLEN; ++_i2) {
82		var pos = 5 * (CSLEN - 1 - _i2);
83		var v2 = chk.shiftRight(new BigInteger('' + pos)).and(BigInteger.fromHex('1f'));
84		result += ALPHABET.charAt(v2.toString(10));
85		}
86
87		return result;
88		}
89
90		function decode(str) {
91		if (str.length < 8) throw new TypeError(str + ' too short');
		0 ignored issues – show Coding Style Best Practice introduced 2018-01-03 13:31 UTC by Report Bug Copy Issue Report Curly braces around statements make for more readable code and help prevent bugs when you add further statements. Consider adding curly braces around all statements when they are executed conditionally. This is optional if there is only one statement, but leaving them out can lead to unexpected behaviour if another statement is added later. Consider: if (a > 0) b = 42; If you or someone else later decides to put another statement in, only the first statement will be executed. if (a > 0) console.log("a > 0"); b = 42; In this case the statement `b = 42` will always be executed, while the logging statement will be executed conditionally. if (a > 0) { console.log("a > 0"); b = 42; } ensures that the proper code will be executed conditionally no matter how many statements are added or removed. Loading history...
92		if (str.length > 90) throw new TypeError(str + ' too long');
		0 ignored issues – show Coding Style Best Practice introduced 2018-01-03 13:31 UTC by Report Bug Copy Issue Report Curly braces around statements make for more readable code and help prevent bugs when you add further statements. Consider adding curly braces around all statements when they are executed conditionally. This is optional if there is only one statement, but leaving them out can lead to unexpected behaviour if another statement is added later. Consider: if (a > 0) b = 42; If you or someone else later decides to put another statement in, only the first statement will be executed. if (a > 0) console.log("a > 0"); b = 42; In this case the statement `b = 42` will always be executed, while the logging statement will be executed conditionally. if (a > 0) { console.log("a > 0"); b = 42; } ensures that the proper code will be executed conditionally no matter how many statements are added or removed. Loading history...
93
94		// don't allow mixed case
95		var lowered = str.toLowerCase();
96		var uppered = str.toUpperCase();
97		if (str !== lowered && str !== uppered) {
98		throw new Error('Mixed-case string ' + str);
99		}
100
101		str = lowered;
102
103		var split = str.lastIndexOf(SEPARATOR);
104		if (split === -1) {
105		throw new Error('No separator character for ' + str);
106		}
107
108		if (split === 0) {
109		throw new Error('Missing prefix for ' + str);
110		}
111
112		var prefix = str.slice(0, split);
113		var wordChars = str.slice(split + 1);
114		if (wordChars.length < 6) {
115		throw new Error('Data too short');
116		}
117
118		var chk = prefixChk(prefix);
119		var words = [];
120		for (var i = 0; i < wordChars.length; ++i) {
121		var c = wordChars.charAt(i);
122		var v = ALPHABET_MAP[c];
123		if (v === undefined) {
124		throw new Error('Unknown character ' + c);
125		}
126
127		chk = polymodStep(chk).xor(new BigInteger('' + v));
128		// not in the checksum?
129		if (i + CSLEN >= wordChars.length) {
130		continue;
131		}
132		words.push(v);
133		}
134
135		if (chk.toString(10) !== '1') {
136		throw new Error('Invalid checksum for ' + str);
137		}
138
139		return { prefix: prefix, words: words };
140		}
141
142		function convert(data, inBits, outBits, pad) {
143		var value = 0;
144		var bits = 0;
145		var maxV = (1 << outBits) - 1;
146
147		var result = [];
148		for (var i = 0; i < data.length; ++i) {
149		value = value << inBits \| data[i];
150		bits += inBits;
151
152		while (bits >= outBits) {
153		bits -= outBits;
154		result.push(value >>> bits & maxV);
155		}
156		}
157
158		if (pad) {
159		if (bits > 0) {
160		result.push(value << outBits - bits & maxV);
161		}
162		} else {
163		if (bits >= inBits) {
164		throw new Error('Excess padding');
165		}
166		if (value << outBits - bits & maxV) {
		0 ignored issues – show introduced 2018-01-03 13:38 UTC by Report Bug Copy Issue Report You have used a bitwise operator `&` in a condition. Did you maybe want to use the logical operator `&&` Loading history...
167		throw new Error('Non-zero padding');
168		}
169		}
170
171		return result;
172		}
173
174		function toWords(bytes) {
175		return convert(bytes, 8, 5, true);
176		}
177
178		function fromWords(words) {
179		return convert(words, 5, 8, false);
180		}
181
182		module.exports = { decode: decode, encode: encode, toWords: toWords, fromWords: fromWords };
183

btccom / cashaddress-js

Pull Request — master (#1)

index.js ➔ decode C

Complexity

Size

Duplication

Importance

How to fix Long Method Complexity

Long Method

Complexity

Duplication Side-by-Side

Filter issues like