]>
Commit | Line | Data |
---|---|---|
eb39fafa DC |
1 | /** |
2 | * @fileoverview Rule to check for "block scoped" variables by binding context | |
3 | * @author Matt DuVall <http://www.mattduvall.com> | |
4 | */ | |
5 | "use strict"; | |
6 | ||
7 | //------------------------------------------------------------------------------ | |
8 | // Rule Definition | |
9 | //------------------------------------------------------------------------------ | |
10 | ||
34eeec05 | 11 | /** @type {import('../shared/types').Rule} */ |
eb39fafa DC |
12 | module.exports = { |
13 | meta: { | |
14 | type: "suggestion", | |
15 | ||
16 | docs: { | |
8f9d1d4d | 17 | description: "Enforce the use of variables within the scope they are defined", |
eb39fafa | 18 | recommended: false, |
f2a92ac6 | 19 | url: "https://eslint.org/docs/latest/rules/block-scoped-var" |
eb39fafa DC |
20 | }, |
21 | ||
22 | schema: [], | |
23 | ||
24 | messages: { | |
25 | outOfScope: "'{{name}}' used outside of binding context." | |
26 | } | |
27 | }, | |
28 | ||
29 | create(context) { | |
30 | let stack = []; | |
f2a92ac6 | 31 | const sourceCode = context.sourceCode; |
eb39fafa DC |
32 | |
33 | /** | |
34 | * Makes a block scope. | |
35 | * @param {ASTNode} node A node of a scope. | |
36 | * @returns {void} | |
37 | */ | |
38 | function enterScope(node) { | |
39 | stack.push(node.range); | |
40 | } | |
41 | ||
42 | /** | |
43 | * Pops the last block scope. | |
44 | * @returns {void} | |
45 | */ | |
46 | function exitScope() { | |
47 | stack.pop(); | |
48 | } | |
49 | ||
50 | /** | |
51 | * Reports a given reference. | |
52 | * @param {eslint-scope.Reference} reference A reference to report. | |
53 | * @returns {void} | |
54 | */ | |
55 | function report(reference) { | |
56 | const identifier = reference.identifier; | |
57 | ||
58 | context.report({ node: identifier, messageId: "outOfScope", data: { name: identifier.name } }); | |
59 | } | |
60 | ||
61 | /** | |
62 | * Finds and reports references which are outside of valid scopes. | |
63 | * @param {ASTNode} node A node to get variables. | |
64 | * @returns {void} | |
65 | */ | |
66 | function checkForVariables(node) { | |
67 | if (node.kind !== "var") { | |
68 | return; | |
69 | } | |
70 | ||
71 | // Defines a predicate to check whether or not a given reference is outside of valid scope. | |
72 | const scopeRange = stack[stack.length - 1]; | |
73 | ||
74 | /** | |
75 | * Check if a reference is out of scope | |
76 | * @param {ASTNode} reference node to examine | |
77 | * @returns {boolean} True is its outside the scope | |
78 | * @private | |
79 | */ | |
80 | function isOutsideOfScope(reference) { | |
81 | const idRange = reference.identifier.range; | |
82 | ||
83 | return idRange[0] < scopeRange[0] || idRange[1] > scopeRange[1]; | |
84 | } | |
85 | ||
86 | // Gets declared variables, and checks its references. | |
f2a92ac6 | 87 | const variables = sourceCode.getDeclaredVariables(node); |
eb39fafa DC |
88 | |
89 | for (let i = 0; i < variables.length; ++i) { | |
90 | ||
91 | // Reports. | |
92 | variables[i] | |
93 | .references | |
94 | .filter(isOutsideOfScope) | |
95 | .forEach(report); | |
96 | } | |
97 | } | |
98 | ||
99 | return { | |
100 | Program(node) { | |
101 | stack = [node.range]; | |
102 | }, | |
103 | ||
104 | // Manages scopes. | |
105 | BlockStatement: enterScope, | |
106 | "BlockStatement:exit": exitScope, | |
107 | ForStatement: enterScope, | |
108 | "ForStatement:exit": exitScope, | |
109 | ForInStatement: enterScope, | |
110 | "ForInStatement:exit": exitScope, | |
111 | ForOfStatement: enterScope, | |
112 | "ForOfStatement:exit": exitScope, | |
113 | SwitchStatement: enterScope, | |
114 | "SwitchStatement:exit": exitScope, | |
115 | CatchClause: enterScope, | |
116 | "CatchClause:exit": exitScope, | |
609c276f TL |
117 | StaticBlock: enterScope, |
118 | "StaticBlock:exit": exitScope, | |
eb39fafa DC |
119 | |
120 | // Finds and reports references which are outside of valid scope. | |
121 | VariableDeclaration: checkForVariables | |
122 | }; | |
123 | ||
124 | } | |
125 | }; |