An error occurred while loading the file. Please try again.
-
Rosanny Sihombing authoredcea2f272
/** * @fileoverview Rule to disallow unnecessary labels * @author Toru Nagashima */"use strict";//------------------------------------------------------------------------------// Requirements//------------------------------------------------------------------------------const astUtils = require("./utils/ast-utils");//------------------------------------------------------------------------------// Rule Definition//------------------------------------------------------------------------------module.exports = { meta: { type: "suggestion", docs: { description: "disallow unnecessary labels", category: "Best Practices", recommended: false, url: "https://eslint.org/docs/rules/no-extra-label" }, schema: [], fixable: "code", messages: { unexpected: "This label '{{name}}' is unnecessary." } }, create(context) { const sourceCode = context.getSourceCode(); let scopeInfo = null; /** * Creates a new scope with a breakable statement. * @param {ASTNode} node A node to create. This is a BreakableStatement. * @returns {void} */ function enterBreakableStatement(node) { scopeInfo = { label: node.parent.type === "LabeledStatement" ? node.parent.label : null, breakable: true, upper: scopeInfo }; } /** * Removes the top scope of the stack. * @returns {void} */ function exitBreakableStatement() { scopeInfo = scopeInfo.upper; } /** * Creates a new scope with a labeled statement. * * This ignores it if the body is a breakable statement. * In this case it's handled in the `enterBreakableStatement` function. * @param {ASTNode} node A node to create. This is a LabeledStatement. * @returns {void} */ function enterLabeledStatement(node) {
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
if (!astUtils.isBreakableStatement(node.body)) {
scopeInfo = {
label: node.label,
breakable: false,
upper: scopeInfo
};
}
}
/**
* Removes the top scope of the stack.
*
* This ignores it if the body is a breakable statement.
* In this case it's handled in the `exitBreakableStatement` function.
* @param {ASTNode} node A node. This is a LabeledStatement.
* @returns {void}
*/
function exitLabeledStatement(node) {
if (!astUtils.isBreakableStatement(node.body)) {
scopeInfo = scopeInfo.upper;
}
}
/**
* Reports a given control node if it's unnecessary.
* @param {ASTNode} node A node. This is a BreakStatement or a
* ContinueStatement.
* @returns {void}
*/
function reportIfUnnecessary(node) {
if (!node.label) {
return;
}
const labelNode = node.label;
for (let info = scopeInfo; info !== null; info = info.upper) {
if (info.breakable || info.label && info.label.name === labelNode.name) {
if (info.breakable && info.label && info.label.name === labelNode.name) {
context.report({
node: labelNode,
messageId: "unexpected",
data: labelNode,
fix(fixer) {
const breakOrContinueToken = sourceCode.getFirstToken(node);
if (sourceCode.commentsExistBetween(breakOrContinueToken, labelNode)) {
return null;
}
return fixer.removeRange([breakOrContinueToken.range[1], labelNode.range[1]]);
}
});
}
return;
}
}
}
return {
WhileStatement: enterBreakableStatement,
"WhileStatement:exit": exitBreakableStatement,
DoWhileStatement: enterBreakableStatement,
"DoWhileStatement:exit": exitBreakableStatement,
ForStatement: enterBreakableStatement,
"ForStatement:exit": exitBreakableStatement,
ForInStatement: enterBreakableStatement,
"ForInStatement:exit": exitBreakableStatement,
ForOfStatement: enterBreakableStatement,
"ForOfStatement:exit": exitBreakableStatement,
SwitchStatement: enterBreakableStatement,
"SwitchStatement:exit": exitBreakableStatement,
LabeledStatement: enterLabeledStatement,
"LabeledStatement:exit": exitLabeledStatement,
BreakStatement: reportIfUnnecessary,
ContinueStatement: reportIfUnnecessary
};
}
};