140 lines
5.2 KiB
JavaScript
140 lines
5.2 KiB
JavaScript
/**
|
|
* @fileoverview Rule to check for implicit global variables, functions and classes.
|
|
* @author Joshua Peek
|
|
*/
|
|
|
|
"use strict";
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Rule Definition
|
|
//------------------------------------------------------------------------------
|
|
|
|
module.exports = {
|
|
meta: {
|
|
type: "suggestion",
|
|
|
|
docs: {
|
|
description: "disallow declarations in the global scope",
|
|
category: "Best Practices",
|
|
recommended: false,
|
|
url: "https://eslint.org/docs/rules/no-implicit-globals"
|
|
},
|
|
|
|
schema: [{
|
|
type: "object",
|
|
properties: {
|
|
lexicalBindings: {
|
|
type: "boolean",
|
|
default: false
|
|
}
|
|
},
|
|
additionalProperties: false
|
|
}],
|
|
|
|
messages: {
|
|
globalNonLexicalBinding: "Unexpected {{kind}} declaration in the global scope, wrap in an IIFE for a local variable, assign as global property for a global variable.",
|
|
globalLexicalBinding: "Unexpected {{kind}} declaration in the global scope, wrap in a block or in an IIFE.",
|
|
globalVariableLeak: "Global variable leak, declare the variable if it is intended to be local.",
|
|
assignmentToReadonlyGlobal: "Unexpected assignment to read-only global variable.",
|
|
redeclarationOfReadonlyGlobal: "Unexpected redeclaration of read-only global variable."
|
|
}
|
|
},
|
|
|
|
create(context) {
|
|
|
|
const checkLexicalBindings = context.options[0] && context.options[0].lexicalBindings === true;
|
|
|
|
/**
|
|
* Reports the node.
|
|
* @param {ASTNode} node Node to report.
|
|
* @param {string} messageId Id of the message to report.
|
|
* @param {string|undefined} kind Declaration kind, can be 'var', 'const', 'let', function or class.
|
|
* @returns {void}
|
|
*/
|
|
function report(node, messageId, kind) {
|
|
context.report({
|
|
node,
|
|
messageId,
|
|
data: {
|
|
kind
|
|
}
|
|
});
|
|
}
|
|
|
|
return {
|
|
Program() {
|
|
const scope = context.getScope();
|
|
|
|
scope.variables.forEach(variable => {
|
|
|
|
// Only ESLint global variables have the `writable` key.
|
|
const isReadonlyEslintGlobalVariable = variable.writeable === false;
|
|
const isWritableEslintGlobalVariable = variable.writeable === true;
|
|
|
|
if (isWritableEslintGlobalVariable) {
|
|
|
|
// Everything is allowed with writable ESLint global variables.
|
|
return;
|
|
}
|
|
|
|
variable.defs.forEach(def => {
|
|
const defNode = def.node;
|
|
|
|
if (def.type === "FunctionName" || (def.type === "Variable" && def.parent.kind === "var")) {
|
|
if (isReadonlyEslintGlobalVariable) {
|
|
report(defNode, "redeclarationOfReadonlyGlobal");
|
|
} else {
|
|
report(
|
|
defNode,
|
|
"globalNonLexicalBinding",
|
|
def.type === "FunctionName" ? "function" : `'${def.parent.kind}'`
|
|
);
|
|
}
|
|
}
|
|
|
|
if (checkLexicalBindings) {
|
|
if (def.type === "ClassName" ||
|
|
(def.type === "Variable" && (def.parent.kind === "let" || def.parent.kind === "const"))) {
|
|
if (isReadonlyEslintGlobalVariable) {
|
|
report(defNode, "redeclarationOfReadonlyGlobal");
|
|
} else {
|
|
report(
|
|
defNode,
|
|
"globalLexicalBinding",
|
|
def.type === "ClassName" ? "class" : `'${def.parent.kind}'`
|
|
);
|
|
}
|
|
}
|
|
}
|
|
});
|
|
});
|
|
|
|
// Undeclared assigned variables.
|
|
scope.implicit.variables.forEach(variable => {
|
|
const scopeVariable = scope.set.get(variable.name);
|
|
let messageId;
|
|
|
|
if (scopeVariable) {
|
|
|
|
// ESLint global variable
|
|
if (scopeVariable.writeable) {
|
|
return;
|
|
}
|
|
messageId = "assignmentToReadonlyGlobal";
|
|
|
|
} else {
|
|
|
|
// Reference to an unknown variable, possible global leak.
|
|
messageId = "globalVariableLeak";
|
|
}
|
|
|
|
// def.node is an AssignmentExpression, ForInStatement or ForOfStatement.
|
|
variable.defs.forEach(def => {
|
|
report(def.node, messageId);
|
|
});
|
|
});
|
|
}
|
|
};
|
|
|
|
}
|
|
};
|