Current Dev State

static/js/ketcher2/node_modules/eslint/lib/rules/curly.js

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+/**
+ * @fileoverview Rule to flag statements without curly braces
+ * @author Nicholas C. Zakas
+ */
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const astUtils = require("../ast-utils");
+const esUtils = require("esutils");
+
+//------------------------------------------------------------------------------
+// Rule Definition
+//------------------------------------------------------------------------------
+
+module.exports = {
+    meta: {
+        docs: {
+            description: "enforce consistent brace style for all control statements",
+            category: "Best Practices",
+            recommended: false
+        },
+
+        schema: {
+            anyOf: [
+                {
+                    type: "array",
+                    items: [
+                        {
+                            enum: ["all"]
+                        }
+                    ],
+                    minItems: 0,
+                    maxItems: 1
+                },
+                {
+                    type: "array",
+                    items: [
+                        {
+                            enum: ["multi", "multi-line", "multi-or-nest"]
+                        },
+                        {
+                            enum: ["consistent"]
+                        }
+                    ],
+                    minItems: 0,
+                    maxItems: 2
+                }
+            ]
+        },
+
+        fixable: "code"
+    },
+
+    create(context) {
+
+        const multiOnly = (context.options[0] === "multi");
+        const multiLine = (context.options[0] === "multi-line");
+        const multiOrNest = (context.options[0] === "multi-or-nest");
+        const consistent = (context.options[1] === "consistent");
+
+        const sourceCode = context.getSourceCode();
+
+        //--------------------------------------------------------------------------
+        // Helpers
+        //--------------------------------------------------------------------------
+
+        /**
+         * Determines if a given node is a one-liner that's on the same line as it's preceding code.
+         * @param {ASTNode} node The node to check.
+         * @returns {boolean} True if the node is a one-liner that's on the same line as it's preceding code.
+         * @private
+         */
+        function isCollapsedOneLiner(node) {
+            const before = sourceCode.getTokenBefore(node);
+            const last = sourceCode.getLastToken(node);
+            const lastExcludingSemicolon = astUtils.isSemicolonToken(last) ? sourceCode.getTokenBefore(last) : last;
+
+            return before.loc.start.line === lastExcludingSemicolon.loc.end.line;
+        }
+
+        /**
+         * Determines if a given node is a one-liner.
+         * @param {ASTNode} node The node to check.
+         * @returns {boolean} True if the node is a one-liner.
+         * @private
+         */
+        function isOneLiner(node) {
+            const first = sourceCode.getFirstToken(node),
+                last = sourceCode.getLastToken(node);
+
+            return first.loc.start.line === last.loc.end.line;
+        }
+
+        /**
+         * Checks if the given token is an `else` token or not.
+         *
+         * @param {Token} token - The token to check.
+         * @returns {boolean} `true` if the token is an `else` token.
+         */
+        function isElseKeywordToken(token) {
+            return token.value === "else" && token.type === "Keyword";
+        }
+
+        /**
+         * Gets the `else` keyword token of a given `IfStatement` node.
+         * @param {ASTNode} node - A `IfStatement` node to get.
+         * @returns {Token} The `else` keyword token.
+         */
+        function getElseKeyword(node) {
+            return node.alternate && sourceCode.getFirstTokenBetween(node.consequent, node.alternate, isElseKeywordToken);
+        }
+
+        /**
+         * Checks a given IfStatement node requires braces of the consequent chunk.
+         * This returns `true` when below:
+         *
+         * 1. The given node has the `alternate` node.
+         * 2. There is a `IfStatement` which doesn't have `alternate` node in the
+         *    trailing statement chain of the `consequent` node.
+         *
+         * @param {ASTNode} node - A IfStatement node to check.
+         * @returns {boolean} `true` if the node requires braces of the consequent chunk.
+         */
+        function requiresBraceOfConsequent(node) {
+            if (node.alternate && node.consequent.type === "BlockStatement") {
+                if (node.consequent.body.length >= 2) {
+                    return true;
+                }
+
+                node = node.consequent.body[0];
+                while (node) {
+                    if (node.type === "IfStatement" && !node.alternate) {
+                        return true;
+                    }
+                    node = astUtils.getTrailingStatement(node);
+                }
+            }
+
+            return false;
+        }
+
+        /**
+         * Reports "Expected { after ..." error
+         * @param {ASTNode} node The node to report.
+         * @param {ASTNode} bodyNode The body node that is incorrectly missing curly brackets
+         * @param {string} name The name to report.
+         * @param {string} suffix Additional string to add to the end of a report.
+         * @returns {void}
+         * @private
+         */
+        function reportExpectedBraceError(node, bodyNode, name, suffix) {
+            context.report({
+                node,
+                loc: (name !== "else" ? node : getElseKeyword(node)).loc.start,
+                message: "Expected { after '{{name}}'{{suffix}}.",
+                data: {
+                    name,
+                    suffix: (suffix ? ` ${suffix}` : "")
+                },
+                fix: fixer => fixer.replaceText(bodyNode, `{${sourceCode.getText(bodyNode)}}`)
+            });
+        }
+
+        /**
+        * Determines if a semicolon needs to be inserted after removing a set of curly brackets, in order to avoid a SyntaxError.
+        * @param {Token} closingBracket The } token
+        * @returns {boolean} `true` if a semicolon needs to be inserted after the last statement in the block.
+        */
+        function needsSemicolon(closingBracket) {
+            const tokenBefore = sourceCode.getTokenBefore(closingBracket);
+            const tokenAfter = sourceCode.getTokenAfter(closingBracket);
+            const lastBlockNode = sourceCode.getNodeByRangeIndex(tokenBefore.range[0]);
+
+            if (astUtils.isSemicolonToken(tokenBefore)) {
+
+                // If the last statement already has a semicolon, don't add another one.
+                return false;
+            }
+
+            if (!tokenAfter) {
+
+                // If there are no statements after this block, there is no need to add a semicolon.
+                return false;
+            }
+
+            if (lastBlockNode.type === "BlockStatement" && lastBlockNode.parent.type !== "FunctionExpression" && lastBlockNode.parent.type !== "ArrowFunctionExpression") {
+
+                // If the last node surrounded by curly brackets is a BlockStatement (other than a FunctionExpression or an ArrowFunctionExpression),
+                // don't insert a semicolon. Otherwise, the semicolon would be parsed as a separate statement, which would cause
+                // a SyntaxError if it was followed by `else`.
+                return false;
+            }
+
+            if (tokenBefore.loc.end.line === tokenAfter.loc.start.line) {
+
+                // If the next token is on the same line, insert a semicolon.
+                return true;
+            }
+
+            if (/^[([/`+-]/.test(tokenAfter.value)) {
+
+                // If the next token starts with a character that would disrupt ASI, insert a semicolon.
+                return true;
+            }
+
+            if (tokenBefore.type === "Punctuator" && (tokenBefore.value === "++" || tokenBefore.value === "--")) {
+
+                // If the last token is ++ or --, insert a semicolon to avoid disrupting ASI.
+                return true;
+            }
+
+            // Otherwise, do not insert a semicolon.
+            return false;
+        }
+
+        /**
+         * Reports "Unnecessary { after ..." error
+         * @param {ASTNode} node The node to report.
+         * @param {ASTNode} bodyNode The block statement that is incorrectly surrounded by parens
+         * @param {string} name The name to report.
+         * @param {string} suffix Additional string to add to the end of a report.
+         * @returns {void}
+         * @private
+         */
+        function reportUnnecessaryBraceError(node, bodyNode, name, suffix) {
+            context.report({
+                node,
+                loc: (name !== "else" ? node : getElseKeyword(node)).loc.start,
+                message: "Unnecessary { after '{{name}}'{{suffix}}.",
+                data: {
+                    name,
+                    suffix: (suffix ? ` ${suffix}` : "")
+                },
+                fix(fixer) {
+
+                    // `do while` expressions sometimes need a space to be inserted after `do`.
+                    // e.g. `do{foo()} while (bar)` should be corrected to `do foo() while (bar)`
+                    const needsPrecedingSpace = node.type === "DoWhileStatement" &&
+                        sourceCode.getTokenBefore(bodyNode).end === bodyNode.start &&
+                        esUtils.code.isIdentifierPartES6(sourceCode.getText(bodyNode).charCodeAt(1));
+
+                    const openingBracket = sourceCode.getFirstToken(bodyNode);
+                    const closingBracket = sourceCode.getLastToken(bodyNode);
+                    const lastTokenInBlock = sourceCode.getTokenBefore(closingBracket);
+
+                    if (needsSemicolon(closingBracket)) {
+
+                        /*
+                         * If removing braces would cause a SyntaxError due to multiple statements on the same line (or
+                         * change the semantics of the code due to ASI), don't perform a fix.
+                         */
+                        return null;
+                    }
+
+                    const resultingBodyText = sourceCode.getText().slice(openingBracket.range[1], lastTokenInBlock.range[0]) +
+                        sourceCode.getText(lastTokenInBlock) +
+                        sourceCode.getText().slice(lastTokenInBlock.range[1], closingBracket.range[0]);
+
+                    return fixer.replaceText(bodyNode, (needsPrecedingSpace ? " " : "") + resultingBodyText);
+                }
+            });
+        }
+
+        /**
+         * Prepares to check the body of a node to see if it's a block statement.
+         * @param {ASTNode} node The node to report if there's a problem.
+         * @param {ASTNode} body The body node to check for blocks.
+         * @param {string} name The name to report if there's a problem.
+         * @param {string} suffix Additional string to add to the end of a report.
+         * @returns {Object} a prepared check object, with "actual", "expected", "check" properties.
+         *   "actual" will be `true` or `false` whether the body is already a block statement.
+         *   "expected" will be `true` or `false` if the body should be a block statement or not, or
+         *   `null` if it doesn't matter, depending on the rule options. It can be modified to change
+         *   the final behavior of "check".
+         *   "check" will be a function reporting appropriate problems depending on the other
+         *   properties.
+         */
+        function prepareCheck(node, body, name, suffix) {
+            const hasBlock = (body.type === "BlockStatement");
+            let expected = null;
+
+            if (node.type === "IfStatement" && node.consequent === body && requiresBraceOfConsequent(node)) {
+                expected = true;
+            } else if (multiOnly) {
+                if (hasBlock && body.body.length === 1) {
+                    expected = false;
+                }
+            } else if (multiLine) {
+                if (!isCollapsedOneLiner(body)) {
+                    expected = true;
+                }
+            } else if (multiOrNest) {
+                if (hasBlock && body.body.length === 1 && isOneLiner(body.body[0])) {
+                    const leadingComments = sourceCode.getComments(body.body[0]).leading;
+
+                    expected = leadingComments.length > 0;
+                } else if (!isOneLiner(body)) {
+                    expected = true;
+                }
+            } else {
+                expected = true;
+            }
+
+            return {
+                actual: hasBlock,
+                expected,
+                check() {
+                    if (this.expected !== null && this.expected !== this.actual) {
+                        if (this.expected) {
+                            reportExpectedBraceError(node, body, name, suffix);
+                        } else {
+                            reportUnnecessaryBraceError(node, body, name, suffix);
+                        }
+                    }
+                }
+            };
+        }
+
+        /**
+         * Prepares to check the bodies of a "if", "else if" and "else" chain.
+         * @param {ASTNode} node The first IfStatement node of the chain.
+         * @returns {Object[]} prepared checks for each body of the chain. See `prepareCheck` for more
+         *   information.
+         */
+        function prepareIfChecks(node) {
+            const preparedChecks = [];
+
+            do {
+                preparedChecks.push(prepareCheck(node, node.consequent, "if", "condition"));
+                if (node.alternate && node.alternate.type !== "IfStatement") {
+                    preparedChecks.push(prepareCheck(node, node.alternate, "else"));
+                    break;
+                }
+                node = node.alternate;
+            } while (node);
+
+            if (consistent) {
+
+                /*
+                 * If any node should have or already have braces, make sure they
+                 * all have braces.
+                 * If all nodes shouldn't have braces, make sure they don't.
+                 */
+                const expected = preparedChecks.some(preparedCheck => {
+                    if (preparedCheck.expected !== null) {
+                        return preparedCheck.expected;
+                    }
+                    return preparedCheck.actual;
+                });
+
+                preparedChecks.forEach(preparedCheck => {
+                    preparedCheck.expected = expected;
+                });
+            }
+
+            return preparedChecks;
+        }
+
+        //--------------------------------------------------------------------------
+        // Public
+        //--------------------------------------------------------------------------
+
+        return {
+            IfStatement(node) {
+                if (node.parent.type !== "IfStatement") {
+                    prepareIfChecks(node).forEach(preparedCheck => {
+                        preparedCheck.check();
+                    });
+                }
+            },
+
+            WhileStatement(node) {
+                prepareCheck(node, node.body, "while", "condition").check();
+            },
+
+            DoWhileStatement(node) {
+                prepareCheck(node, node.body, "do").check();
+            },
+
+            ForStatement(node) {
+                prepareCheck(node, node.body, "for", "condition").check();
+            },
+
+            ForInStatement(node) {
+                prepareCheck(node, node.body, "for-in").check();
+            },
+
+            ForOfStatement(node) {
+                prepareCheck(node, node.body, "for-of").check();
+            }
+        };
+    }
+};