1
|
function isAbsolute(pathname) {
|
2
|
return pathname.charAt(0) === '/';
|
3
|
}
|
4
|
|
5
|
// About 1.5x faster than the two-arg version of Array#splice()
|
6
|
function spliceOne(list, index) {
|
7
|
for (var i = index, k = i + 1, n = list.length; k < n; i += 1, k += 1) {
|
8
|
list[i] = list[k];
|
9
|
}
|
10
|
|
11
|
list.pop();
|
12
|
}
|
13
|
|
14
|
// This implementation is based heavily on node's url.parse
|
15
|
function resolvePathname(to, from) {
|
16
|
if (from === undefined) from = '';
|
17
|
|
18
|
var toParts = (to && to.split('/')) || [];
|
19
|
var fromParts = (from && from.split('/')) || [];
|
20
|
|
21
|
var isToAbs = to && isAbsolute(to);
|
22
|
var isFromAbs = from && isAbsolute(from);
|
23
|
var mustEndAbs = isToAbs || isFromAbs;
|
24
|
|
25
|
if (to && isAbsolute(to)) {
|
26
|
// to is absolute
|
27
|
fromParts = toParts;
|
28
|
} else if (toParts.length) {
|
29
|
// to is relative, drop the filename
|
30
|
fromParts.pop();
|
31
|
fromParts = fromParts.concat(toParts);
|
32
|
}
|
33
|
|
34
|
if (!fromParts.length) return '/';
|
35
|
|
36
|
var hasTrailingSlash;
|
37
|
if (fromParts.length) {
|
38
|
var last = fromParts[fromParts.length - 1];
|
39
|
hasTrailingSlash = last === '.' || last === '..' || last === '';
|
40
|
} else {
|
41
|
hasTrailingSlash = false;
|
42
|
}
|
43
|
|
44
|
var up = 0;
|
45
|
for (var i = fromParts.length; i >= 0; i--) {
|
46
|
var part = fromParts[i];
|
47
|
|
48
|
if (part === '.') {
|
49
|
spliceOne(fromParts, i);
|
50
|
} else if (part === '..') {
|
51
|
spliceOne(fromParts, i);
|
52
|
up++;
|
53
|
} else if (up) {
|
54
|
spliceOne(fromParts, i);
|
55
|
up--;
|
56
|
}
|
57
|
}
|
58
|
|
59
|
if (!mustEndAbs) for (; up--; up) fromParts.unshift('..');
|
60
|
|
61
|
if (
|
62
|
mustEndAbs &&
|
63
|
fromParts[0] !== '' &&
|
64
|
(!fromParts[0] || !isAbsolute(fromParts[0]))
|
65
|
)
|
66
|
fromParts.unshift('');
|
67
|
|
68
|
var result = fromParts.join('/');
|
69
|
|
70
|
if (hasTrailingSlash && result.substr(-1) !== '/') result += '/';
|
71
|
|
72
|
return result;
|
73
|
}
|
74
|
|
75
|
export default resolvePathname;
|