Constnium/node_modules/eslint-plugin-n/lib/rules/process-exit-as-throw.js

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2022-06-23 02:27:43 +02:00
/**
* @author Toru Nagashima
* See LICENSE file in root directory for full license.
*/
"use strict"
const CodePathAnalyzer = safeRequire(
"eslint/lib/linter/code-path-analysis/code-path-analyzer",
"eslint/lib/code-path-analysis/code-path-analyzer"
)
const CodePathSegment = safeRequire(
"eslint/lib/linter/code-path-analysis/code-path-segment",
"eslint/lib/code-path-analysis/code-path-segment"
)
const CodePath = safeRequire(
"eslint/lib/linter/code-path-analysis/code-path",
"eslint/lib/code-path-analysis/code-path"
)
const originalLeaveNode =
CodePathAnalyzer && CodePathAnalyzer.prototype.leaveNode
/**
* Imports a specific module.
* @param {...string} moduleNames - module names to import.
* @returns {object|null} The imported object, or null.
*/
function safeRequire(...moduleNames) {
for (const moduleName of moduleNames) {
try {
return require(moduleName)
} catch (_err) {
// Ignore.
}
}
return null
}
/* istanbul ignore next */
/**
* Copied from https://github.com/eslint/eslint/blob/16fad5880bb70e9dddbeab8ed0f425ae51f5841f/lib/code-path-analysis/code-path-analyzer.js#L137
*
* @param {CodePathAnalyzer} analyzer - The instance.
* @param {ASTNode} node - The current AST node.
* @returns {void}
*/
function forwardCurrentToHead(analyzer, node) {
const codePath = analyzer.codePath
const state = CodePath.getState(codePath)
const currentSegments = state.currentSegments
const headSegments = state.headSegments
const end = Math.max(currentSegments.length, headSegments.length)
let i = 0
let currentSegment = null
let headSegment = null
// Fires leaving events.
for (i = 0; i < end; ++i) {
currentSegment = currentSegments[i]
headSegment = headSegments[i]
if (currentSegment !== headSegment && currentSegment) {
if (currentSegment.reachable) {
analyzer.emitter.emit(
"onCodePathSegmentEnd",
currentSegment,
node
)
}
}
}
// Update state.
state.currentSegments = headSegments
// Fires entering events.
for (i = 0; i < end; ++i) {
currentSegment = currentSegments[i]
headSegment = headSegments[i]
if (currentSegment !== headSegment && headSegment) {
CodePathSegment.markUsed(headSegment)
if (headSegment.reachable) {
analyzer.emitter.emit(
"onCodePathSegmentStart",
headSegment,
node
)
}
}
}
}
/**
* Checks whether a given node is `process.exit()` or not.
*
* @param {ASTNode} node - A node to check.
* @returns {boolean} `true` if the node is `process.exit()`.
*/
function isProcessExit(node) {
return (
node.type === "CallExpression" &&
node.callee.type === "MemberExpression" &&
node.callee.computed === false &&
node.callee.object.type === "Identifier" &&
node.callee.object.name === "process" &&
node.callee.property.type === "Identifier" &&
node.callee.property.name === "exit"
)
}
/**
* The function to override `CodePathAnalyzer.prototype.leaveNode` in order to
* address `process.exit()` as throw.
*
* @this CodePathAnalyzer
* @param {ASTNode} node - A node to be left.
* @returns {void}
*/
function overrideLeaveNode(node) {
if (isProcessExit(node)) {
this.currentNode = node
forwardCurrentToHead(this, node)
CodePath.getState(this.codePath).makeThrow()
this.original.leaveNode(node)
this.currentNode = null
} else {
originalLeaveNode.call(this, node)
}
}
const visitor =
CodePathAnalyzer == null
? {}
: {
Program: function installProcessExitAsThrow() {
CodePathAnalyzer.prototype.leaveNode = overrideLeaveNode
},
"Program:exit": function restoreProcessExitAsThrow() {
CodePathAnalyzer.prototype.leaveNode = originalLeaveNode
},
}
module.exports = {
meta: {
docs: {
description:
"make `process.exit()` expressions the same code path as `throw`",
category: "Possible Errors",
recommended: true,
url: "https://github.com/weiran-zsd/eslint-plugin-node/blob/HEAD/docs/rules/process-exit-as-throw.md",
},
type: "problem",
fixable: null,
schema: [],
supported: CodePathAnalyzer != null,
},
create() {
return visitor
},
}