1 | const { sep, join, dirname } = require('path');
|
2 | const { existsSync, statSync, readFileSync } = require('fs-extra');
|
3 |
|
4 | function startsWith(prevString, nextString) {
|
5 | return prevString.indexOf(nextString) === 0;
|
6 | }
|
7 |
|
8 | function startsWithArr(prevString, nextStringArr = []) {
|
9 | return nextStringArr.some(nextString => startsWith(prevString, nextString));
|
10 | }
|
11 |
|
12 | function loadAsFile(module, extension) {
|
13 | if (existsSync(module + extension) && statSync(module + extension).isFile()) {
|
14 | return module + extension;
|
15 | }
|
16 |
|
17 | if (existsSync(module) && statSync(module).isFile()) {
|
18 | return module;
|
19 | }
|
20 | }
|
21 |
|
22 | function loadAsDirectory(module, extension) {
|
23 | if (!existsSync(module)) {
|
24 | return;
|
25 | }
|
26 |
|
27 | let stat = statSync(module);
|
28 |
|
29 | if (stat.isDirectory()) {
|
30 | const packagePath = join(module, 'package.json');
|
31 | const indexFile = join(module, 'index' + extension);
|
32 | if (existsSync(packagePath) && statSync(packagePath).isFile()) {
|
33 | let pkg = JSON.parse(readFileSync(packagePath, 'utf-8'));
|
34 | let main = join(module, pkg.main || 'index' + extension);
|
35 | return loadAsFile(main) || loadAsDirectory(main);
|
36 | } else if (existsSync(indexFile) && statSync(indexFile).isFile()) {
|
37 | return indexFile;
|
38 | }
|
39 | } else if (stat.isFile()) {
|
40 | return loadAsFile(module, extension);
|
41 | }
|
42 | }
|
43 |
|
44 | function nodeModulesPaths(start) {
|
45 | let parts = start.split(sep);
|
46 |
|
47 | if (!parts[parts.length - 1]) {
|
48 | parts.pop();
|
49 | }
|
50 |
|
51 | let i = parts.length - 1;
|
52 | let dirs = [];
|
53 | while (i >= 0) {
|
54 | if ('node_modules' === parts[i]) {
|
55 | i -= 1;
|
56 | continue;
|
57 | }
|
58 | let dir = join(parts.slice(0, i + 1).join(sep) || sep, 'node_modules');
|
59 | dirs.push(dir);
|
60 | i -= 1;
|
61 | }
|
62 | return dirs;
|
63 | }
|
64 |
|
65 | function loadNpmModules(module, start, extension) {
|
66 | let target;
|
67 | let paths = nodeModulesPaths(start);
|
68 |
|
69 | for (let i = 0; i < paths.length; ++i) {
|
70 | let dependencyPath = join(paths[i], module);
|
71 | target = loadAsFile(dependencyPath, extension) || loadAsDirectory(dependencyPath, extension);
|
72 |
|
73 | if (target) {
|
74 | break;
|
75 | }
|
76 | }
|
77 | return target;
|
78 | }
|
79 |
|
80 |
|
81 |
|
82 |
|
83 |
|
84 |
|
85 |
|
86 |
|
87 | function moduleResolve(script, dependency, extension = '.js') {
|
88 | let target;
|
89 |
|
90 | if (startsWithArr(dependency, ['./', '../', '/', '.\\', '..\\', '\\'])) {
|
91 | let dependencyPath = join(script, dependency);
|
92 | target = loadAsFile(dependencyPath, extension) || loadAsDirectory(dependencyPath, extension);
|
93 | } else {
|
94 | target = loadNpmModules(dependency, dirname(script), extension);
|
95 | }
|
96 | return target;
|
97 | };
|
98 |
|
99 |
|
100 |
|
101 |
|
102 |
|
103 |
|
104 |
|
105 |
|
106 |
|
107 | function multipleModuleResolve(script, dependency, extensions = []) {
|
108 | for (let extension of extensions) {
|
109 | const target = moduleResolve(script, dependency, extension);
|
110 | if (target) {
|
111 | return target;
|
112 | }
|
113 | }
|
114 | return null;
|
115 | }
|
116 |
|
117 | module.exports = {
|
118 | moduleResolve,
|
119 | multipleModuleResolve
|
120 | };
|