1
|
/* eslint-disable guard-for-in */
|
2
|
'use strict';
|
3
|
var repeating = require('repeating');
|
4
|
|
5
|
// detect either spaces or tabs but not both to properly handle tabs
|
6
|
// for indentation and spaces for alignment
|
7
|
var INDENT_RE = /^(?:( )+|\t+)/;
|
8
|
|
9
|
function getMostUsed(indents) {
|
10
|
var result = 0;
|
11
|
var maxUsed = 0;
|
12
|
var maxWeight = 0;
|
13
|
|
14
|
for (var n in indents) {
|
15
|
var indent = indents[n];
|
16
|
var u = indent[0];
|
17
|
var w = indent[1];
|
18
|
|
19
|
if (u > maxUsed || u === maxUsed && w > maxWeight) {
|
20
|
maxUsed = u;
|
21
|
maxWeight = w;
|
22
|
result = Number(n);
|
23
|
}
|
24
|
}
|
25
|
|
26
|
return result;
|
27
|
}
|
28
|
|
29
|
module.exports = function (str) {
|
30
|
if (typeof str !== 'string') {
|
31
|
throw new TypeError('Expected a string');
|
32
|
}
|
33
|
|
34
|
// used to see if tabs or spaces are the most used
|
35
|
var tabs = 0;
|
36
|
var spaces = 0;
|
37
|
|
38
|
// remember the size of previous line's indentation
|
39
|
var prev = 0;
|
40
|
|
41
|
// remember how many indents/unindents as occurred for a given size
|
42
|
// and how much lines follow a given indentation
|
43
|
//
|
44
|
// indents = {
|
45
|
// 3: [1, 0],
|
46
|
// 4: [1, 5],
|
47
|
// 5: [1, 0],
|
48
|
// 12: [1, 0],
|
49
|
// }
|
50
|
var indents = {};
|
51
|
|
52
|
// pointer to the array of last used indent
|
53
|
var current;
|
54
|
|
55
|
// whether the last action was an indent (opposed to an unindent)
|
56
|
var isIndent;
|
57
|
|
58
|
str.split(/\n/g).forEach(function (line) {
|
59
|
if (!line) {
|
60
|
// ignore empty lines
|
61
|
return;
|
62
|
}
|
63
|
|
64
|
var indent;
|
65
|
var matches = line.match(INDENT_RE);
|
66
|
|
67
|
if (!matches) {
|
68
|
indent = 0;
|
69
|
} else {
|
70
|
indent = matches[0].length;
|
71
|
|
72
|
if (matches[1]) {
|
73
|
spaces++;
|
74
|
} else {
|
75
|
tabs++;
|
76
|
}
|
77
|
}
|
78
|
|
79
|
var diff = indent - prev;
|
80
|
prev = indent;
|
81
|
|
82
|
if (diff) {
|
83
|
// an indent or unindent has been detected
|
84
|
|
85
|
isIndent = diff > 0;
|
86
|
|
87
|
current = indents[isIndent ? diff : -diff];
|
88
|
|
89
|
if (current) {
|
90
|
current[0]++;
|
91
|
} else {
|
92
|
current = indents[diff] = [1, 0];
|
93
|
}
|
94
|
} else if (current) {
|
95
|
// if the last action was an indent, increment the weight
|
96
|
current[1] += Number(isIndent);
|
97
|
}
|
98
|
});
|
99
|
|
100
|
var amount = getMostUsed(indents);
|
101
|
|
102
|
var type;
|
103
|
var actual;
|
104
|
if (!amount) {
|
105
|
type = null;
|
106
|
actual = '';
|
107
|
} else if (spaces >= tabs) {
|
108
|
type = 'space';
|
109
|
actual = repeating(' ', amount);
|
110
|
} else {
|
111
|
type = 'tab';
|
112
|
actual = repeating('\t', amount);
|
113
|
}
|
114
|
|
115
|
return {
|
116
|
amount: amount,
|
117
|
type: type,
|
118
|
indent: actual
|
119
|
};
|
120
|
};
|