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
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
|
/**
* @fileoverview Restrict usage of duplicate imports.
* @author Simen Bekkhus
*/
"use strict";
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
/**
* Returns the name of the module imported or re-exported.
* @param {ASTNode} node A node to get.
* @returns {string} the name of the module, or empty string if no name.
*/
function getValue(node) {
if (node && node.source && node.source.value) {
return node.source.value.trim();
}
return "";
}
/**
* Checks if the name of the import or export exists in the given array, and reports if so.
* @param {RuleContext} context The ESLint rule context object.
* @param {ASTNode} node A node to get.
* @param {string} value The name of the imported or exported module.
* @param {string[]} array The array containing other imports or exports in the file.
* @param {string} messageId A messageId to be reported after the name of the module
*
* @returns {void} No return value
*/
function checkAndReport(context, node, value, array, messageId) {
if (array.indexOf(value) !== -1) {
context.report({
node,
messageId,
data: {
module: value
}
});
}
}
/**
* @callback nodeCallback
* @param {ASTNode} node A node to handle.
*/
/**
* Returns a function handling the imports of a given file
* @param {RuleContext} context The ESLint rule context object.
* @param {boolean} includeExports Whether or not to check for exports in addition to imports.
* @param {string[]} importsInFile The array containing other imports in the file.
* @param {string[]} exportsInFile The array containing other exports in the file.
*
* @returns {nodeCallback} A function passed to ESLint to handle the statement.
*/
function handleImports(context, includeExports, importsInFile, exportsInFile) {
return function(node) {
const value = getValue(node);
if (value) {
checkAndReport(context, node, value, importsInFile, "import");
if (includeExports) {
checkAndReport(context, node, value, exportsInFile, "importAs");
}
importsInFile.push(value);
}
};
}
/**
* Returns a function handling the exports of a given file
* @param {RuleContext} context The ESLint rule context object.
* @param {string[]} importsInFile The array containing other imports in the file.
* @param {string[]} exportsInFile The array containing other exports in the file.
*
* @returns {nodeCallback} A function passed to ESLint to handle the statement.
*/
function handleExports(context, importsInFile, exportsInFile) {
return function(node) {
const value = getValue(node);
if (value) {
checkAndReport(context, node, value, exportsInFile, "export");
checkAndReport(context, node, value, importsInFile, "exportAs");
exportsInFile.push(value);
}
};
}
module.exports = {
meta: {
type: "problem",
docs: {
description: "disallow duplicate module imports",
category: "ECMAScript 6",
recommended: false,
url: "https://eslint.org/docs/rules/no-duplicate-imports"
},
schema: [{
type: "object",
properties: {
includeExports: {
type: "boolean",
default: false
}
},
additionalProperties: false
}],
messages: {
import: "'{{module}}' import is duplicated.",
importAs: "'{{module}}' import is duplicated as export.",
export: "'{{module}}' export is duplicated.",
exportAs: "'{{module}}' export is duplicated as import."
}
},
create(context) {
const includeExports = (context.options[0] || {}).includeExports,
importsInFile = [],
exportsInFile = [];
const handlers = {
ImportDeclaration: handleImports(context, includeExports, importsInFile, exportsInFile)
};
if (includeExports) {
handlers.ExportNamedDeclaration = handleExports(context, importsInFile, exportsInFile);
handlers.ExportAllDeclaration = handleExports(context, importsInFile, exportsInFile);
}
return handlers;
}
};
|
