336 lines
12 KiB
JavaScript
336 lines
12 KiB
JavaScript
/**
|
|
* @fileoverview Rule to flag missing semicolons.
|
|
* @author Nicholas C. Zakas
|
|
*/
|
|
"use strict";
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Requirements
|
|
//------------------------------------------------------------------------------
|
|
|
|
const FixTracker = require("./utils/fix-tracker");
|
|
const astUtils = require("./utils/ast-utils");
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Rule Definition
|
|
//------------------------------------------------------------------------------
|
|
|
|
module.exports = {
|
|
meta: {
|
|
type: "layout",
|
|
|
|
docs: {
|
|
description: "require or disallow semicolons instead of ASI",
|
|
category: "Stylistic Issues",
|
|
recommended: false,
|
|
url: "https://eslint.org/docs/rules/semi"
|
|
},
|
|
|
|
fixable: "code",
|
|
|
|
schema: {
|
|
anyOf: [
|
|
{
|
|
type: "array",
|
|
items: [
|
|
{
|
|
enum: ["never"]
|
|
},
|
|
{
|
|
type: "object",
|
|
properties: {
|
|
beforeStatementContinuationChars: {
|
|
enum: ["always", "any", "never"]
|
|
}
|
|
},
|
|
additionalProperties: false
|
|
}
|
|
],
|
|
minItems: 0,
|
|
maxItems: 2
|
|
},
|
|
{
|
|
type: "array",
|
|
items: [
|
|
{
|
|
enum: ["always"]
|
|
},
|
|
{
|
|
type: "object",
|
|
properties: {
|
|
omitLastInOneLineBlock: { type: "boolean" }
|
|
},
|
|
additionalProperties: false
|
|
}
|
|
],
|
|
minItems: 0,
|
|
maxItems: 2
|
|
}
|
|
]
|
|
},
|
|
|
|
messages: {
|
|
missingSemi: "Missing semicolon.",
|
|
extraSemi: "Extra semicolon."
|
|
}
|
|
},
|
|
|
|
create(context) {
|
|
|
|
const OPT_OUT_PATTERN = /^[-[(/+`]/u; // One of [(/+-`
|
|
const options = context.options[1];
|
|
const never = context.options[0] === "never";
|
|
const exceptOneLine = Boolean(options && options.omitLastInOneLineBlock);
|
|
const beforeStatementContinuationChars = options && options.beforeStatementContinuationChars || "any";
|
|
const sourceCode = context.getSourceCode();
|
|
|
|
//--------------------------------------------------------------------------
|
|
// Helpers
|
|
//--------------------------------------------------------------------------
|
|
|
|
/**
|
|
* Reports a semicolon error with appropriate location and message.
|
|
* @param {ASTNode} node The node with an extra or missing semicolon.
|
|
* @param {boolean} missing True if the semicolon is missing.
|
|
* @returns {void}
|
|
*/
|
|
function report(node, missing) {
|
|
const lastToken = sourceCode.getLastToken(node);
|
|
let messageId,
|
|
fix,
|
|
loc;
|
|
|
|
if (!missing) {
|
|
messageId = "missingSemi";
|
|
loc = {
|
|
start: lastToken.loc.end,
|
|
end: astUtils.getNextLocation(sourceCode, lastToken.loc.end)
|
|
};
|
|
fix = function(fixer) {
|
|
return fixer.insertTextAfter(lastToken, ";");
|
|
};
|
|
} else {
|
|
messageId = "extraSemi";
|
|
loc = lastToken.loc;
|
|
fix = function(fixer) {
|
|
|
|
/*
|
|
* Expand the replacement range to include the surrounding
|
|
* tokens to avoid conflicting with no-extra-semi.
|
|
* https://github.com/eslint/eslint/issues/7928
|
|
*/
|
|
return new FixTracker(fixer, sourceCode)
|
|
.retainSurroundingTokens(lastToken)
|
|
.remove(lastToken);
|
|
};
|
|
}
|
|
|
|
context.report({
|
|
node,
|
|
loc,
|
|
messageId,
|
|
fix
|
|
});
|
|
|
|
}
|
|
|
|
/**
|
|
* Check whether a given semicolon token is redundant.
|
|
* @param {Token} semiToken A semicolon token to check.
|
|
* @returns {boolean} `true` if the next token is `;` or `}`.
|
|
*/
|
|
function isRedundantSemi(semiToken) {
|
|
const nextToken = sourceCode.getTokenAfter(semiToken);
|
|
|
|
return (
|
|
!nextToken ||
|
|
astUtils.isClosingBraceToken(nextToken) ||
|
|
astUtils.isSemicolonToken(nextToken)
|
|
);
|
|
}
|
|
|
|
/**
|
|
* Check whether a given token is the closing brace of an arrow function.
|
|
* @param {Token} lastToken A token to check.
|
|
* @returns {boolean} `true` if the token is the closing brace of an arrow function.
|
|
*/
|
|
function isEndOfArrowBlock(lastToken) {
|
|
if (!astUtils.isClosingBraceToken(lastToken)) {
|
|
return false;
|
|
}
|
|
const node = sourceCode.getNodeByRangeIndex(lastToken.range[0]);
|
|
|
|
return (
|
|
node.type === "BlockStatement" &&
|
|
node.parent.type === "ArrowFunctionExpression"
|
|
);
|
|
}
|
|
|
|
/**
|
|
* Check whether a given node is on the same line with the next token.
|
|
* @param {Node} node A statement node to check.
|
|
* @returns {boolean} `true` if the node is on the same line with the next token.
|
|
*/
|
|
function isOnSameLineWithNextToken(node) {
|
|
const prevToken = sourceCode.getLastToken(node, 1);
|
|
const nextToken = sourceCode.getTokenAfter(node);
|
|
|
|
return !!nextToken && astUtils.isTokenOnSameLine(prevToken, nextToken);
|
|
}
|
|
|
|
/**
|
|
* Check whether a given node can connect the next line if the next line is unreliable.
|
|
* @param {Node} node A statement node to check.
|
|
* @returns {boolean} `true` if the node can connect the next line.
|
|
*/
|
|
function maybeAsiHazardAfter(node) {
|
|
const t = node.type;
|
|
|
|
if (t === "DoWhileStatement" ||
|
|
t === "BreakStatement" ||
|
|
t === "ContinueStatement" ||
|
|
t === "DebuggerStatement" ||
|
|
t === "ImportDeclaration" ||
|
|
t === "ExportAllDeclaration"
|
|
) {
|
|
return false;
|
|
}
|
|
if (t === "ReturnStatement") {
|
|
return Boolean(node.argument);
|
|
}
|
|
if (t === "ExportNamedDeclaration") {
|
|
return Boolean(node.declaration);
|
|
}
|
|
if (isEndOfArrowBlock(sourceCode.getLastToken(node, 1))) {
|
|
return false;
|
|
}
|
|
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* Check whether a given token can connect the previous statement.
|
|
* @param {Token} token A token to check.
|
|
* @returns {boolean} `true` if the token is one of `[`, `(`, `/`, `+`, `-`, ```, `++`, and `--`.
|
|
*/
|
|
function maybeAsiHazardBefore(token) {
|
|
return (
|
|
Boolean(token) &&
|
|
OPT_OUT_PATTERN.test(token.value) &&
|
|
token.value !== "++" &&
|
|
token.value !== "--"
|
|
);
|
|
}
|
|
|
|
/**
|
|
* Check if the semicolon of a given node is unnecessary, only true if:
|
|
* - next token is a valid statement divider (`;` or `}`).
|
|
* - next token is on a new line and the node is not connectable to the new line.
|
|
* @param {Node} node A statement node to check.
|
|
* @returns {boolean} whether the semicolon is unnecessary.
|
|
*/
|
|
function canRemoveSemicolon(node) {
|
|
if (isRedundantSemi(sourceCode.getLastToken(node))) {
|
|
return true; // `;;` or `;}`
|
|
}
|
|
if (isOnSameLineWithNextToken(node)) {
|
|
return false; // One liner.
|
|
}
|
|
if (beforeStatementContinuationChars === "never" && !maybeAsiHazardAfter(node)) {
|
|
return true; // ASI works. This statement doesn't connect to the next.
|
|
}
|
|
if (!maybeAsiHazardBefore(sourceCode.getTokenAfter(node))) {
|
|
return true; // ASI works. The next token doesn't connect to this statement.
|
|
}
|
|
|
|
return false;
|
|
}
|
|
|
|
/**
|
|
* Checks a node to see if it's in a one-liner block statement.
|
|
* @param {ASTNode} node The node to check.
|
|
* @returns {boolean} whether the node is in a one-liner block statement.
|
|
*/
|
|
function isOneLinerBlock(node) {
|
|
const parent = node.parent;
|
|
const nextToken = sourceCode.getTokenAfter(node);
|
|
|
|
if (!nextToken || nextToken.value !== "}") {
|
|
return false;
|
|
}
|
|
return (
|
|
!!parent &&
|
|
parent.type === "BlockStatement" &&
|
|
parent.loc.start.line === parent.loc.end.line
|
|
);
|
|
}
|
|
|
|
/**
|
|
* Checks a node to see if it's followed by a semicolon.
|
|
* @param {ASTNode} node The node to check.
|
|
* @returns {void}
|
|
*/
|
|
function checkForSemicolon(node) {
|
|
const isSemi = astUtils.isSemicolonToken(sourceCode.getLastToken(node));
|
|
|
|
if (never) {
|
|
if (isSemi && canRemoveSemicolon(node)) {
|
|
report(node, true);
|
|
} else if (!isSemi && beforeStatementContinuationChars === "always" && maybeAsiHazardBefore(sourceCode.getTokenAfter(node))) {
|
|
report(node);
|
|
}
|
|
} else {
|
|
const oneLinerBlock = (exceptOneLine && isOneLinerBlock(node));
|
|
|
|
if (isSemi && oneLinerBlock) {
|
|
report(node, true);
|
|
} else if (!isSemi && !oneLinerBlock) {
|
|
report(node);
|
|
}
|
|
}
|
|
}
|
|
|
|
/**
|
|
* Checks to see if there's a semicolon after a variable declaration.
|
|
* @param {ASTNode} node The node to check.
|
|
* @returns {void}
|
|
*/
|
|
function checkForSemicolonForVariableDeclaration(node) {
|
|
const parent = node.parent;
|
|
|
|
if ((parent.type !== "ForStatement" || parent.init !== node) &&
|
|
(!/^For(?:In|Of)Statement/u.test(parent.type) || parent.left !== node)
|
|
) {
|
|
checkForSemicolon(node);
|
|
}
|
|
}
|
|
|
|
//--------------------------------------------------------------------------
|
|
// Public API
|
|
//--------------------------------------------------------------------------
|
|
|
|
return {
|
|
VariableDeclaration: checkForSemicolonForVariableDeclaration,
|
|
ExpressionStatement: checkForSemicolon,
|
|
ReturnStatement: checkForSemicolon,
|
|
ThrowStatement: checkForSemicolon,
|
|
DoWhileStatement: checkForSemicolon,
|
|
DebuggerStatement: checkForSemicolon,
|
|
BreakStatement: checkForSemicolon,
|
|
ContinueStatement: checkForSemicolon,
|
|
ImportDeclaration: checkForSemicolon,
|
|
ExportAllDeclaration: checkForSemicolon,
|
|
ExportNamedDeclaration(node) {
|
|
if (!node.declaration) {
|
|
checkForSemicolon(node);
|
|
}
|
|
},
|
|
ExportDefaultDeclaration(node) {
|
|
if (!/(?:Class|Function)Declaration/u.test(node.declaration.type)) {
|
|
checkForSemicolon(node);
|
|
}
|
|
}
|
|
};
|
|
|
|
}
|
|
};
|