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
|
/**
* @fileoverview A rule to control the style of variable initializations.
* @author Colin Ihrig
*/
"use strict";
//------------------------------------------------------------------------------
// Helpers
//------------------------------------------------------------------------------
/**
* Checks whether or not a given node is a for loop.
* @param {ASTNode} block - A node to check.
* @returns {boolean} `true` when the node is a for loop.
*/
function isForLoop(block) {
return block.type === "ForInStatement" ||
block.type === "ForOfStatement" ||
block.type === "ForStatement";
}
/**
* Checks whether or not a given declarator node has its initializer.
* @param {ASTNode} node - A declarator node to check.
* @returns {boolean} `true` when the node has its initializer.
*/
function isInitialized(node) {
let declaration = node.parent;
let block = declaration.parent;
if (isForLoop(block)) {
if (block.type === "ForStatement") {
return block.init === declaration;
}
return block.left === declaration;
}
return Boolean(node.init);
}
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
module.exports = {
meta: {
docs: {
description: "require or disallow initialization in `var` declarations",
category: "Variables",
recommended: false
},
schema: {
anyOf: [
{
type: "array",
items: [
{
enum: ["always"]
}
],
minItems: 0,
maxItems: 1
},
{
type: "array",
items: [
{
enum: ["never"]
},
{
type: "object",
properties: {
ignoreForLoopInit: {
type: "boolean"
}
},
additionalProperties: false
}
],
minItems: 0,
maxItems: 2
}
]
}
},
create: function(context) {
let MODE_ALWAYS = "always",
MODE_NEVER = "never";
let mode = context.options[0] || MODE_ALWAYS;
let params = context.options[1] || {};
//--------------------------------------------------------------------------
// Public API
//--------------------------------------------------------------------------
return {
"VariableDeclaration:exit": function(node) {
let kind = node.kind,
declarations = node.declarations;
for (let i = 0; i < declarations.length; ++i) {
let declaration = declarations[i],
id = declaration.id,
initialized = isInitialized(declaration),
isIgnoredForLoop = params.ignoreForLoopInit && isForLoop(node.parent);
if (id.type !== "Identifier") {
continue;
}
if (mode === MODE_ALWAYS && !initialized) {
context.report(declaration, "Variable '" + id.name + "' should be initialized on declaration.");
} else if (mode === MODE_NEVER && kind !== "const" && initialized && !isIgnoredForLoop) {
context.report(declaration, "Variable '" + id.name + "' should not be initialized on declaration.");
}
}
}
};
}
};
|
