twreporter-react
Version:
React-Redux site for The Reporter Foundation in Taiwan
225 lines (189 loc) • 7.6 kB
JavaScript
/**
* @fileoverview Comma spacing - validates spacing before and after comma
* @author Vignesh Anand aka vegetableman.
* @copyright 2014 Vignesh Anand. All rights reserved.
*/
;
var astUtils = require("../ast-utils");
//------------------------------------------------------------------------------
// Rule Definition
//------------------------------------------------------------------------------
module.exports = function(context) {
var sourceCode = context.getSourceCode();
var options = {
before: context.options[0] ? !!context.options[0].before : false,
after: context.options[0] ? !!context.options[0].after : true
};
//--------------------------------------------------------------------------
// Helpers
//--------------------------------------------------------------------------
// the index of the last comment that was checked
var lastCommentIndex = 0;
var allComments;
// list of comma tokens to ignore for the check of leading whitespace
var commaTokensToIgnore = [];
/**
* Determines if a given token is a comma operator.
* @param {ASTNode} token The token to check.
* @returns {boolean} True if the token is a comma, false if not.
* @private
*/
function isComma(token) {
return !!token && (token.type === "Punctuator") && (token.value === ",");
}
/**
* Determines if a given source index is in a comment or not by checking
* the index against the comment range. Since the check goes straight
* through the file, once an index is passed a certain comment, we can
* go to the next comment to check that.
* @param {int} index The source index to check.
* @param {ASTNode[]} comments An array of comment nodes.
* @returns {boolean} True if the index is within a comment, false if not.
* @private
*/
function isIndexInComment(index, comments) {
var comment;
lastCommentIndex = 0;
while (lastCommentIndex < comments.length) {
comment = comments[lastCommentIndex];
if (comment.range[0] <= index && index < comment.range[1]) {
return true;
} else if (index > comment.range[1]) {
lastCommentIndex++;
} else {
break;
}
}
return false;
}
/**
* Reports a spacing error with an appropriate message.
* @param {ASTNode} node The binary expression node to report.
* @param {string} dir Is the error "before" or "after" the comma?
* @param {ASTNode} otherNode The node at the left or right of `node`
* @returns {void}
* @private
*/
function report(node, dir, otherNode) {
context.report({
node: node,
fix: function(fixer) {
if (options[dir]) {
if (dir === "before") {
return fixer.insertTextBefore(node, " ");
} else {
return fixer.insertTextAfter(node, " ");
}
} else {
/*
* Comments handling
*/
var start, end;
var newText = "";
if (dir === "before") {
start = otherNode.range[1];
end = node.range[0];
} else {
start = node.range[1];
end = otherNode.range[0];
}
for (var i = start; i < end; i++) {
if (isIndexInComment(i, allComments)) {
newText += context.getSource()[i];
}
}
return fixer.replaceTextRange([start, end], newText);
}
},
message: options[dir] ?
"A space is required " + dir + " ','." :
"There should be no space " + dir + " ','."
});
}
/**
* Validates the spacing around a comma token.
* @param {Object} tokens - The tokens to be validated.
* @param {Token} tokens.comma The token representing the comma.
* @param {Token} [tokens.left] The last token before the comma.
* @param {Token} [tokens.right] The first token after the comma.
* @param {Token|ASTNode} reportItem The item to use when reporting an error.
* @returns {void}
* @private
*/
function validateCommaItemSpacing(tokens, reportItem) {
if (tokens.left && astUtils.isTokenOnSameLine(tokens.left, tokens.comma) &&
(options.before !== sourceCode.isSpaceBetweenTokens(tokens.left, tokens.comma))
) {
report(reportItem, "before", tokens.left);
}
if (tokens.right && astUtils.isTokenOnSameLine(tokens.comma, tokens.right) &&
(options.after !== sourceCode.isSpaceBetweenTokens(tokens.comma, tokens.right))
) {
report(reportItem, "after", tokens.right);
}
}
/**
* Adds null elements of the given ArrayExpression or ArrayPattern node to the ignore list.
* @param {ASTNode} node An ArrayExpression or ArrayPattern node.
* @returns {void}
*/
function addNullElementsToIgnoreList(node) {
var previousToken = context.getFirstToken(node);
node.elements.forEach(function(element) {
var token;
if (element === null) {
token = context.getTokenAfter(previousToken);
if (isComma(token)) {
commaTokensToIgnore.push(token);
}
} else {
token = context.getTokenAfter(element);
}
previousToken = token;
});
}
//--------------------------------------------------------------------------
// Public
//--------------------------------------------------------------------------
return {
"Program:exit": function() {
var source = context.getSource(),
pattern = /,/g,
commaToken,
previousToken,
nextToken;
allComments = context.getAllComments();
while (pattern.test(source)) {
// do not flag anything inside of comments
if (!isIndexInComment(pattern.lastIndex, allComments)) {
commaToken = context.getTokenByRangeStart(pattern.lastIndex - 1);
if (commaToken && commaToken.type !== "JSXText") {
previousToken = context.getTokenBefore(commaToken);
nextToken = context.getTokenAfter(commaToken);
validateCommaItemSpacing({
comma: commaToken,
left: isComma(previousToken) || commaTokensToIgnore.indexOf(commaToken) > -1 ? null : previousToken,
right: isComma(nextToken) ? null : nextToken
}, commaToken);
}
}
}
},
"ArrayExpression": addNullElementsToIgnoreList,
"ArrayPattern": addNullElementsToIgnoreList
};
};
module.exports.schema = [
{
"type": "object",
"properties": {
"before": {
"type": "boolean"
},
"after": {
"type": "boolean"
}
},
"additionalProperties": false
}
];