1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
|
use std::error::Error;
use std::fmt;
use url::ParseError;
use url::Url;
/// Error indicating the reason resolving a module specifier failed.
#[derive(Clone, Copy, Debug, Eq, PartialEq)]
pub enum ModuleResolutionError {
InvalidUrl(ParseError),
InvalidBaseUrl(ParseError),
ImportPathPrefixMissing,
}
use ModuleResolutionError::*;
impl Error for ModuleResolutionError {
fn source(&self) -> Option<&(dyn Error + 'static)> {
match self {
InvalidUrl(ref err) | InvalidBaseUrl(ref err) => Some(err),
_ => None,
}
}
}
impl fmt::Display for ModuleResolutionError {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
match self {
InvalidUrl(ref err) => write!(f, "invalid URL: {}", err),
InvalidBaseUrl(ref err) => {
write!(f, "invalid base URL for relative import: {}", err)
}
ImportPathPrefixMissing => {
write!(f, "relative import path not prefixed with / or ./ or ../")
}
}
}
}
#[derive(Debug, Clone, PartialEq)]
/// Resolved module specifier
pub struct ModuleSpecifier(Url);
impl ModuleSpecifier {
pub fn to_url(&self) -> Url {
self.0.clone()
}
/// Resolves module using this algorithm:
/// https://html.spec.whatwg.org/multipage/webappapis.html#resolve-a-module-specifier
pub fn resolve(
specifier: &str,
base: &str,
) -> Result<ModuleSpecifier, ModuleResolutionError> {
let url = match Url::parse(specifier) {
// 1. Apply the URL parser to specifier.
// If the result is not failure, return he result.
Ok(url) => url,
// 2. If specifier does not start with the character U+002F SOLIDUS (/),
// the two-character sequence U+002E FULL STOP, U+002F SOLIDUS (./),
// or the three-character sequence U+002E FULL STOP, U+002E FULL STOP,
// U+002F SOLIDUS (../), return failure.
Err(ParseError::RelativeUrlWithoutBase)
if !(specifier.starts_with('/')
|| specifier.starts_with("./")
|| specifier.starts_with("../")) =>
{
Err(ImportPathPrefixMissing)?
}
// 3. Return the result of applying the URL parser to specifier with base
// URL as the base URL.
Err(ParseError::RelativeUrlWithoutBase) => {
let base = Url::parse(base).map_err(InvalidBaseUrl)?;
base.join(&specifier).map_err(InvalidUrl)?
}
// If parsing the specifier as a URL failed for a different reason than
// it being relative, always return the original error. We don't want to
// return `ImportPathPrefixMissing` or `InvalidBaseUrl` if the real
// problem lies somewhere else.
Err(err) => Err(InvalidUrl(err))?,
};
Ok(ModuleSpecifier(url))
}
/// Takes a string representing a path or URL to a module, but of the type
/// passed through the command-line interface for the main module. This is
/// slightly different than specifiers used in import statements: "foo.js" for
/// example is allowed here, whereas in import statements a leading "./" is
/// required ("./foo.js"). This function is aware of the current working
/// directory and returns an absolute URL.
pub fn resolve_root(
root_specifier: &str,
) -> Result<ModuleSpecifier, ModuleResolutionError> {
let url = match Url::parse(root_specifier) {
Ok(url) => url,
Err(..) => {
let cwd = std::env::current_dir().unwrap();
let base = Url::from_directory_path(cwd).unwrap();
base.join(&root_specifier).map_err(InvalidUrl)?
}
};
Ok(ModuleSpecifier(url))
}
}
impl fmt::Display for ModuleSpecifier {
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result {
self.0.fmt(f)
}
}
impl From<Url> for ModuleSpecifier {
fn from(url: Url) -> Self {
ModuleSpecifier(url)
}
}
impl PartialEq<String> for ModuleSpecifier {
fn eq(&self, other: &String) -> bool {
&self.to_string() == other
}
}
|
