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Diffstat (limited to 'tools/node_modules/eslint/lib/rules/semi.js')
-rw-r--r-- | tools/node_modules/eslint/lib/rules/semi.js | 325 |
1 files changed, 325 insertions, 0 deletions
diff --git a/tools/node_modules/eslint/lib/rules/semi.js b/tools/node_modules/eslint/lib/rules/semi.js new file mode 100644 index 0000000000..78b6966dea --- /dev/null +++ b/tools/node_modules/eslint/lib/rules/semi.js @@ -0,0 +1,325 @@ +/** + * @fileoverview Rule to flag missing semicolons. + * @author Nicholas C. Zakas + */ +"use strict"; + +//------------------------------------------------------------------------------ +// Requirements +//------------------------------------------------------------------------------ + +const FixTracker = require("../util/fix-tracker"); +const astUtils = require("../ast-utils"); + +//------------------------------------------------------------------------------ +// Rule Definition +//------------------------------------------------------------------------------ + +module.exports = { + meta: { + docs: { + description: "require or disallow semicolons instead of ASI", + category: "Stylistic Issues", + recommended: false + }, + + 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 + } + ] + } + }, + + create(context) { + + const OPT_OUT_PATTERN = /^[-[(/+`]/; // 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 message, + fix, + loc = lastToken.loc; + + if (!missing) { + message = "Missing semicolon."; + loc = loc.end; + fix = function(fixer) { + return fixer.insertTextAfter(lastToken, ";"); + }; + } else { + message = "Extra semicolon."; + loc = loc.start; + 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, + message, + fix + }); + + } + + /** + * Check whether a given semicolon token is redandant. + * @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/.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/.test(node.declaration.type)) { + checkForSemicolon(node); + } + } + }; + + } +}; |