source: imaps-frontend/node_modules/eslint/lib/rules/no-import-assign.js

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Last change on this file was d565449, checked in by stefan toskovski <stefantoska84@…>, 4 weeks ago

Update repo after prototype presentation

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1/**
2 * @fileoverview Rule to flag updates of imported bindings.
3 * @author Toru Nagashima <https://github.com/mysticatea>
4 */
5
6"use strict";
7
8//------------------------------------------------------------------------------
9// Helpers
10//------------------------------------------------------------------------------
11
12const { findVariable } = require("@eslint-community/eslint-utils");
13const astUtils = require("./utils/ast-utils");
14
15const WellKnownMutationFunctions = {
16 Object: /^(?:assign|definePropert(?:y|ies)|freeze|setPrototypeOf)$/u,
17 Reflect: /^(?:(?:define|delete)Property|set(?:PrototypeOf)?)$/u
18};
19
20/**
21 * Check if a given node is LHS of an assignment node.
22 * @param {ASTNode} node The node to check.
23 * @returns {boolean} `true` if the node is LHS.
24 */
25function isAssignmentLeft(node) {
26 const { parent } = node;
27
28 return (
29 (
30 parent.type === "AssignmentExpression" &&
31 parent.left === node
32 ) ||
33
34 // Destructuring assignments
35 parent.type === "ArrayPattern" ||
36 (
37 parent.type === "Property" &&
38 parent.value === node &&
39 parent.parent.type === "ObjectPattern"
40 ) ||
41 parent.type === "RestElement" ||
42 (
43 parent.type === "AssignmentPattern" &&
44 parent.left === node
45 )
46 );
47}
48
49/**
50 * Check if a given node is the operand of mutation unary operator.
51 * @param {ASTNode} node The node to check.
52 * @returns {boolean} `true` if the node is the operand of mutation unary operator.
53 */
54function isOperandOfMutationUnaryOperator(node) {
55 const argumentNode = node.parent.type === "ChainExpression"
56 ? node.parent
57 : node;
58 const { parent } = argumentNode;
59
60 return (
61 (
62 parent.type === "UpdateExpression" &&
63 parent.argument === argumentNode
64 ) ||
65 (
66 parent.type === "UnaryExpression" &&
67 parent.operator === "delete" &&
68 parent.argument === argumentNode
69 )
70 );
71}
72
73/**
74 * Check if a given node is the iteration variable of `for-in`/`for-of` syntax.
75 * @param {ASTNode} node The node to check.
76 * @returns {boolean} `true` if the node is the iteration variable.
77 */
78function isIterationVariable(node) {
79 const { parent } = node;
80
81 return (
82 (
83 parent.type === "ForInStatement" &&
84 parent.left === node
85 ) ||
86 (
87 parent.type === "ForOfStatement" &&
88 parent.left === node
89 )
90 );
91}
92
93/**
94 * Check if a given node is at the first argument of a well-known mutation function.
95 * - `Object.assign`
96 * - `Object.defineProperty`
97 * - `Object.defineProperties`
98 * - `Object.freeze`
99 * - `Object.setPrototypeOf`
100 * - `Reflect.defineProperty`
101 * - `Reflect.deleteProperty`
102 * - `Reflect.set`
103 * - `Reflect.setPrototypeOf`
104 * @param {ASTNode} node The node to check.
105 * @param {Scope} scope A `escope.Scope` object to find variable (whichever).
106 * @returns {boolean} `true` if the node is at the first argument of a well-known mutation function.
107 */
108function isArgumentOfWellKnownMutationFunction(node, scope) {
109 const { parent } = node;
110
111 if (parent.type !== "CallExpression" || parent.arguments[0] !== node) {
112 return false;
113 }
114 const callee = astUtils.skipChainExpression(parent.callee);
115
116 if (
117 !astUtils.isSpecificMemberAccess(callee, "Object", WellKnownMutationFunctions.Object) &&
118 !astUtils.isSpecificMemberAccess(callee, "Reflect", WellKnownMutationFunctions.Reflect)
119 ) {
120 return false;
121 }
122 const variable = findVariable(scope, callee.object);
123
124 return variable !== null && variable.scope.type === "global";
125}
126
127/**
128 * Check if the identifier node is placed at to update members.
129 * @param {ASTNode} id The Identifier node to check.
130 * @param {Scope} scope A `escope.Scope` object to find variable (whichever).
131 * @returns {boolean} `true` if the member of `id` was updated.
132 */
133function isMemberWrite(id, scope) {
134 const { parent } = id;
135
136 return (
137 (
138 parent.type === "MemberExpression" &&
139 parent.object === id &&
140 (
141 isAssignmentLeft(parent) ||
142 isOperandOfMutationUnaryOperator(parent) ||
143 isIterationVariable(parent)
144 )
145 ) ||
146 isArgumentOfWellKnownMutationFunction(id, scope)
147 );
148}
149
150/**
151 * Get the mutation node.
152 * @param {ASTNode} id The Identifier node to get.
153 * @returns {ASTNode} The mutation node.
154 */
155function getWriteNode(id) {
156 let node = id.parent;
157
158 while (
159 node &&
160 node.type !== "AssignmentExpression" &&
161 node.type !== "UpdateExpression" &&
162 node.type !== "UnaryExpression" &&
163 node.type !== "CallExpression" &&
164 node.type !== "ForInStatement" &&
165 node.type !== "ForOfStatement"
166 ) {
167 node = node.parent;
168 }
169
170 return node || id;
171}
172
173//------------------------------------------------------------------------------
174// Rule Definition
175//------------------------------------------------------------------------------
176
177/** @type {import('../shared/types').Rule} */
178module.exports = {
179 meta: {
180 type: "problem",
181
182 docs: {
183 description: "Disallow assigning to imported bindings",
184 recommended: true,
185 url: "https://eslint.org/docs/latest/rules/no-import-assign"
186 },
187
188 schema: [],
189
190 messages: {
191 readonly: "'{{name}}' is read-only.",
192 readonlyMember: "The members of '{{name}}' are read-only."
193 }
194 },
195
196 create(context) {
197 const sourceCode = context.sourceCode;
198
199 return {
200 ImportDeclaration(node) {
201 const scope = sourceCode.getScope(node);
202
203 for (const variable of sourceCode.getDeclaredVariables(node)) {
204 const shouldCheckMembers = variable.defs.some(
205 d => d.node.type === "ImportNamespaceSpecifier"
206 );
207 let prevIdNode = null;
208
209 for (const reference of variable.references) {
210 const idNode = reference.identifier;
211
212 /*
213 * AssignmentPattern (e.g. `[a = 0] = b`) makes two write
214 * references for the same identifier. This should skip
215 * the one of the two in order to prevent redundant reports.
216 */
217 if (idNode === prevIdNode) {
218 continue;
219 }
220 prevIdNode = idNode;
221
222 if (reference.isWrite()) {
223 context.report({
224 node: getWriteNode(idNode),
225 messageId: "readonly",
226 data: { name: idNode.name }
227 });
228 } else if (shouldCheckMembers && isMemberWrite(idNode, scope)) {
229 context.report({
230 node: getWriteNode(idNode),
231 messageId: "readonlyMember",
232 data: { name: idNode.name }
233 });
234 }
235 }
236 }
237 }
238 };
239
240 }
241};
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