256 lines
9.6 KiB
JavaScript
256 lines
9.6 KiB
JavaScript
/**
|
|
* @fileoverview Rule to check empty newline after "var" statement
|
|
* @author Gopal Venkatesan
|
|
* @deprecated
|
|
*/
|
|
|
|
"use strict";
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Requirements
|
|
//------------------------------------------------------------------------------
|
|
|
|
const astUtils = require("./utils/ast-utils");
|
|
|
|
//------------------------------------------------------------------------------
|
|
// Rule Definition
|
|
//------------------------------------------------------------------------------
|
|
|
|
module.exports = {
|
|
meta: {
|
|
type: "layout",
|
|
|
|
docs: {
|
|
description: "require or disallow an empty line after variable declarations",
|
|
category: "Stylistic Issues",
|
|
recommended: false,
|
|
url: "https://eslint.org/docs/rules/newline-after-var"
|
|
},
|
|
schema: [
|
|
{
|
|
enum: ["never", "always"]
|
|
}
|
|
],
|
|
fixable: "whitespace",
|
|
messages: {
|
|
expected: "Expected blank line after variable declarations.",
|
|
unexpected: "Unexpected blank line after variable declarations."
|
|
},
|
|
|
|
deprecated: true,
|
|
|
|
replacedBy: ["padding-line-between-statements"]
|
|
},
|
|
|
|
create(context) {
|
|
const sourceCode = context.getSourceCode();
|
|
|
|
// Default `mode` to "always".
|
|
const mode = context.options[0] === "never" ? "never" : "always";
|
|
|
|
// Cache starting and ending line numbers of comments for faster lookup
|
|
const commentEndLine = sourceCode.getAllComments().reduce((result, token) => {
|
|
result[token.loc.start.line] = token.loc.end.line;
|
|
return result;
|
|
}, {});
|
|
|
|
|
|
//--------------------------------------------------------------------------
|
|
// Helpers
|
|
//--------------------------------------------------------------------------
|
|
|
|
/**
|
|
* Gets a token from the given node to compare line to the next statement.
|
|
*
|
|
* In general, the token is the last token of the node. However, the token is the second last token if the following conditions satisfy.
|
|
*
|
|
* - The last token is semicolon.
|
|
* - The semicolon is on a different line from the previous token of the semicolon.
|
|
*
|
|
* This behavior would address semicolon-less style code. e.g.:
|
|
*
|
|
* var foo = 1
|
|
*
|
|
* ;(a || b).doSomething()
|
|
* @param {ASTNode} node The node to get.
|
|
* @returns {Token} The token to compare line to the next statement.
|
|
*/
|
|
function getLastToken(node) {
|
|
const lastToken = sourceCode.getLastToken(node);
|
|
|
|
if (lastToken.type === "Punctuator" && lastToken.value === ";") {
|
|
const prevToken = sourceCode.getTokenBefore(lastToken);
|
|
|
|
if (prevToken.loc.end.line !== lastToken.loc.start.line) {
|
|
return prevToken;
|
|
}
|
|
}
|
|
|
|
return lastToken;
|
|
}
|
|
|
|
/**
|
|
* Determine if provided keyword is a variable declaration
|
|
* @private
|
|
* @param {string} keyword keyword to test
|
|
* @returns {boolean} True if `keyword` is a type of var
|
|
*/
|
|
function isVar(keyword) {
|
|
return keyword === "var" || keyword === "let" || keyword === "const";
|
|
}
|
|
|
|
/**
|
|
* Determine if provided keyword is a variant of for specifiers
|
|
* @private
|
|
* @param {string} keyword keyword to test
|
|
* @returns {boolean} True if `keyword` is a variant of for specifier
|
|
*/
|
|
function isForTypeSpecifier(keyword) {
|
|
return keyword === "ForStatement" || keyword === "ForInStatement" || keyword === "ForOfStatement";
|
|
}
|
|
|
|
/**
|
|
* Determine if provided keyword is an export specifiers
|
|
* @private
|
|
* @param {string} nodeType nodeType to test
|
|
* @returns {boolean} True if `nodeType` is an export specifier
|
|
*/
|
|
function isExportSpecifier(nodeType) {
|
|
return nodeType === "ExportNamedDeclaration" || nodeType === "ExportSpecifier" ||
|
|
nodeType === "ExportDefaultDeclaration" || nodeType === "ExportAllDeclaration";
|
|
}
|
|
|
|
/**
|
|
* Determine if provided node is the last of their parent block.
|
|
* @private
|
|
* @param {ASTNode} node node to test
|
|
* @returns {boolean} True if `node` is last of their parent block.
|
|
*/
|
|
function isLastNode(node) {
|
|
const token = sourceCode.getTokenAfter(node);
|
|
|
|
return !token || (token.type === "Punctuator" && token.value === "}");
|
|
}
|
|
|
|
/**
|
|
* Gets the last line of a group of consecutive comments
|
|
* @param {number} commentStartLine The starting line of the group
|
|
* @returns {number} The number of the last comment line of the group
|
|
*/
|
|
function getLastCommentLineOfBlock(commentStartLine) {
|
|
const currentCommentEnd = commentEndLine[commentStartLine];
|
|
|
|
return commentEndLine[currentCommentEnd + 1] ? getLastCommentLineOfBlock(currentCommentEnd + 1) : currentCommentEnd;
|
|
}
|
|
|
|
/**
|
|
* Determine if a token starts more than one line after a comment ends
|
|
* @param {token} token The token being checked
|
|
* @param {integer} commentStartLine The line number on which the comment starts
|
|
* @returns {boolean} True if `token` does not start immediately after a comment
|
|
*/
|
|
function hasBlankLineAfterComment(token, commentStartLine) {
|
|
return token.loc.start.line > getLastCommentLineOfBlock(commentStartLine) + 1;
|
|
}
|
|
|
|
/**
|
|
* Checks that a blank line exists after a variable declaration when mode is
|
|
* set to "always", or checks that there is no blank line when mode is set
|
|
* to "never"
|
|
* @private
|
|
* @param {ASTNode} node `VariableDeclaration` node to test
|
|
* @returns {void}
|
|
*/
|
|
function checkForBlankLine(node) {
|
|
|
|
/*
|
|
* lastToken is the last token on the node's line. It will usually also be the last token of the node, but it will
|
|
* sometimes be second-last if there is a semicolon on a different line.
|
|
*/
|
|
const lastToken = getLastToken(node),
|
|
|
|
/*
|
|
* If lastToken is the last token of the node, nextToken should be the token after the node. Otherwise, nextToken
|
|
* is the last token of the node.
|
|
*/
|
|
nextToken = lastToken === sourceCode.getLastToken(node) ? sourceCode.getTokenAfter(node) : sourceCode.getLastToken(node),
|
|
nextLineNum = lastToken.loc.end.line + 1;
|
|
|
|
// Ignore if there is no following statement
|
|
if (!nextToken) {
|
|
return;
|
|
}
|
|
|
|
// Ignore if parent of node is a for variant
|
|
if (isForTypeSpecifier(node.parent.type)) {
|
|
return;
|
|
}
|
|
|
|
// Ignore if parent of node is an export specifier
|
|
if (isExportSpecifier(node.parent.type)) {
|
|
return;
|
|
}
|
|
|
|
/*
|
|
* Some coding styles use multiple `var` statements, so do nothing if
|
|
* the next token is a `var` statement.
|
|
*/
|
|
if (nextToken.type === "Keyword" && isVar(nextToken.value)) {
|
|
return;
|
|
}
|
|
|
|
// Ignore if it is last statement in a block
|
|
if (isLastNode(node)) {
|
|
return;
|
|
}
|
|
|
|
// Next statement is not a `var`...
|
|
const noNextLineToken = nextToken.loc.start.line > nextLineNum;
|
|
const hasNextLineComment = (typeof commentEndLine[nextLineNum] !== "undefined");
|
|
|
|
if (mode === "never" && noNextLineToken && !hasNextLineComment) {
|
|
context.report({
|
|
node,
|
|
messageId: "unexpected",
|
|
data: { identifier: node.name },
|
|
fix(fixer) {
|
|
const linesBetween = sourceCode.getText().slice(lastToken.range[1], nextToken.range[0]).split(astUtils.LINEBREAK_MATCHER);
|
|
|
|
return fixer.replaceTextRange([lastToken.range[1], nextToken.range[0]], `${linesBetween.slice(0, -1).join("")}\n${linesBetween[linesBetween.length - 1]}`);
|
|
}
|
|
});
|
|
}
|
|
|
|
// Token on the next line, or comment without blank line
|
|
if (
|
|
mode === "always" && (
|
|
!noNextLineToken ||
|
|
hasNextLineComment && !hasBlankLineAfterComment(nextToken, nextLineNum)
|
|
)
|
|
) {
|
|
context.report({
|
|
node,
|
|
messageId: "expected",
|
|
data: { identifier: node.name },
|
|
fix(fixer) {
|
|
if ((noNextLineToken ? getLastCommentLineOfBlock(nextLineNum) : lastToken.loc.end.line) === nextToken.loc.start.line) {
|
|
return fixer.insertTextBefore(nextToken, "\n\n");
|
|
}
|
|
|
|
return fixer.insertTextBeforeRange([nextToken.range[0] - nextToken.loc.start.column, nextToken.range[1]], "\n");
|
|
}
|
|
});
|
|
}
|
|
}
|
|
|
|
//--------------------------------------------------------------------------
|
|
// Public
|
|
//--------------------------------------------------------------------------
|
|
|
|
return {
|
|
VariableDeclaration: checkForBlankLine
|
|
};
|
|
|
|
}
|
|
};
|