Current Dev State

static/js/ketcher2/node_modules/eslint/lib/util/source-code.js

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+/**
+ * @fileoverview Abstraction of JavaScript source code.
+ * @author Nicholas C. Zakas
+ */
+"use strict";
+
+//------------------------------------------------------------------------------
+// Requirements
+//------------------------------------------------------------------------------
+
+const TokenStore = require("../token-store"),
+    Traverser = require("./traverser"),
+    astUtils = require("../ast-utils"),
+    lodash = require("lodash");
+
+//------------------------------------------------------------------------------
+// Private
+//------------------------------------------------------------------------------
+
+/**
+ * Validates that the given AST has the required information.
+ * @param {ASTNode} ast The Program node of the AST to check.
+ * @throws {Error} If the AST doesn't contain the correct information.
+ * @returns {void}
+ * @private
+ */
+function validate(ast) {
+
+    if (!ast.tokens) {
+        throw new Error("AST is missing the tokens array.");
+    }
+
+    if (!ast.comments) {
+        throw new Error("AST is missing the comments array.");
+    }
+
+    if (!ast.loc) {
+        throw new Error("AST is missing location information.");
+    }
+
+    if (!ast.range) {
+        throw new Error("AST is missing range information");
+    }
+}
+
+/**
+ * Finds a JSDoc comment node in an array of comment nodes.
+ * @param {ASTNode[]} comments The array of comment nodes to search.
+ * @param {int} line Line number to look around
+ * @returns {ASTNode} The node if found, null if not.
+ * @private
+ */
+function findJSDocComment(comments, line) {
+
+    if (comments) {
+        for (let i = comments.length - 1; i >= 0; i--) {
+            if (comments[i].type === "Block" && comments[i].value.charAt(0) === "*") {
+
+                if (line - comments[i].loc.end.line <= 1) {
+                    return comments[i];
+                }
+                break;
+
+            }
+        }
+    }
+
+    return null;
+}
+
+/**
+ * Check to see if its a ES6 export declaration
+ * @param {ASTNode} astNode - any node
+ * @returns {boolean} whether the given node represents a export declaration
+ * @private
+ */
+function looksLikeExport(astNode) {
+    return astNode.type === "ExportDefaultDeclaration" || astNode.type === "ExportNamedDeclaration" ||
+        astNode.type === "ExportAllDeclaration" || astNode.type === "ExportSpecifier";
+}
+
+/**
+ * Merges two sorted lists into a larger sorted list in O(n) time
+ * @param {Token[]} tokens The list of tokens
+ * @param {Token[]} comments The list of comments
+ * @returns {Token[]} A sorted list of tokens and comments
+ */
+function sortedMerge(tokens, comments) {
+    const result = [];
+    let tokenIndex = 0;
+    let commentIndex = 0;
+
+    while (tokenIndex < tokens.length || commentIndex < comments.length) {
+        if (commentIndex >= comments.length || tokenIndex < tokens.length && tokens[tokenIndex].range[0] < comments[commentIndex].range[0]) {
+            result.push(tokens[tokenIndex++]);
+        } else {
+            result.push(comments[commentIndex++]);
+        }
+    }
+
+    return result;
+}
+
+
+//------------------------------------------------------------------------------
+// Public Interface
+//------------------------------------------------------------------------------
+
+/**
+ * Represents parsed source code.
+ * @param {string} text - The source code text.
+ * @param {ASTNode} ast - The Program node of the AST representing the code. This AST should be created from the text that BOM was stripped.
+ * @constructor
+ */
+function SourceCode(text, ast) {
+    validate(ast);
+
+    /**
+     * The flag to indicate that the source code has Unicode BOM.
+     * @type boolean
+     */
+    this.hasBOM = (text.charCodeAt(0) === 0xFEFF);
+
+    /**
+     * The original text source code.
+     * BOM was stripped from this text.
+     * @type string
+     */
+    this.text = (this.hasBOM ? text.slice(1) : text);
+
+    /**
+     * The parsed AST for the source code.
+     * @type ASTNode
+     */
+    this.ast = ast;
+
+    /**
+     * The source code split into lines according to ECMA-262 specification.
+     * This is done to avoid each rule needing to do so separately.
+     * @type string[]
+     */
+    this.lines = [];
+    this.lineStartIndices = [0];
+
+    const lineEndingPattern = astUtils.createGlobalLinebreakMatcher();
+    let match;
+
+    /*
+     * Previously, this was implemented using a regex that
+     * matched a sequence of non-linebreak characters followed by a
+     * linebreak, then adding the lengths of the matches. However,
+     * this caused a catastrophic backtracking issue when the end
+     * of a file contained a large number of non-newline characters.
+     * To avoid this, the current implementation just matches newlines
+     * and uses match.index to get the correct line start indices.
+     */
+    while ((match = lineEndingPattern.exec(this.text))) {
+        this.lines.push(this.text.slice(this.lineStartIndices[this.lineStartIndices.length - 1], match.index));
+        this.lineStartIndices.push(match.index + match[0].length);
+    }
+    this.lines.push(this.text.slice(this.lineStartIndices[this.lineStartIndices.length - 1]));
+
+    this.tokensAndComments = sortedMerge(ast.tokens, ast.comments);
+
+    // create token store methods
+    const tokenStore = new TokenStore(ast.tokens, ast.comments);
+
+    for (const methodName of TokenStore.PUBLIC_METHODS) {
+        this[methodName] = tokenStore[methodName].bind(tokenStore);
+    }
+
+    // don't allow modification of this object
+    Object.freeze(this);
+    Object.freeze(this.lines);
+}
+
+/**
+ * Split the source code into multiple lines based on the line delimiters
+ * @param {string} text Source code as a string
+ * @returns {string[]} Array of source code lines
+ * @public
+ */
+SourceCode.splitLines = function(text) {
+    return text.split(astUtils.createGlobalLinebreakMatcher());
+};
+
+SourceCode.prototype = {
+    constructor: SourceCode,
+
+    /**
+     * Gets the source code for the given node.
+     * @param {ASTNode=} node The AST node to get the text for.
+     * @param {int=} beforeCount The number of characters before the node to retrieve.
+     * @param {int=} afterCount The number of characters after the node to retrieve.
+     * @returns {string} The text representing the AST node.
+     */
+    getText(node, beforeCount, afterCount) {
+        if (node) {
+            return this.text.slice(Math.max(node.range[0] - (beforeCount || 0), 0),
+                node.range[1] + (afterCount || 0));
+        }
+        return this.text;
+
+
+    },
+
+    /**
+     * Gets the entire source text split into an array of lines.
+     * @returns {Array} The source text as an array of lines.
+     */
+    getLines() {
+        return this.lines;
+    },
+
+    /**
+     * Retrieves an array containing all comments in the source code.
+     * @returns {ASTNode[]} An array of comment nodes.
+     */
+    getAllComments() {
+        return this.ast.comments;
+    },
+
+    /**
+     * Gets all comments for the given node.
+     * @param {ASTNode} node The AST node to get the comments for.
+     * @returns {Object} The list of comments indexed by their position.
+     * @public
+     */
+    getComments(node) {
+
+        let leadingComments = node.leadingComments || [];
+        const trailingComments = node.trailingComments || [];
+
+        /*
+         * espree adds a "comments" array on Program nodes rather than
+         * leadingComments/trailingComments. Comments are only left in the
+         * Program node comments array if there is no executable code.
+         */
+        if (node.type === "Program") {
+            if (node.body.length === 0) {
+                leadingComments = node.comments;
+            }
+        }
+
+        return {
+            leading: leadingComments,
+            trailing: trailingComments
+        };
+    },
+
+    /**
+     * Retrieves the JSDoc comment for a given node.
+     * @param {ASTNode} node The AST node to get the comment for.
+     * @returns {ASTNode} The BlockComment node containing the JSDoc for the
+     *      given node or null if not found.
+     * @public
+     */
+    getJSDocComment(node) {
+
+        let parent = node.parent;
+
+        switch (node.type) {
+            case "ClassDeclaration":
+            case "FunctionDeclaration":
+                if (looksLikeExport(parent)) {
+                    return findJSDocComment(parent.leadingComments, parent.loc.start.line);
+                }
+                return findJSDocComment(node.leadingComments, node.loc.start.line);
+
+            case "ClassExpression":
+                return findJSDocComment(parent.parent.leadingComments, parent.parent.loc.start.line);
+
+            case "ArrowFunctionExpression":
+            case "FunctionExpression":
+
+                if (parent.type !== "CallExpression" && parent.type !== "NewExpression") {
+                    while (parent && !parent.leadingComments && !/Function/.test(parent.type) && parent.type !== "MethodDefinition" && parent.type !== "Property") {
+                        parent = parent.parent;
+                    }
+
+                    return parent && (parent.type !== "FunctionDeclaration") ? findJSDocComment(parent.leadingComments, parent.loc.start.line) : null;
+                } else if (node.leadingComments) {
+                    return findJSDocComment(node.leadingComments, node.loc.start.line);
+                }
+
+            // falls through
+
+            default:
+                return null;
+        }
+    },
+
+    /**
+     * Gets the deepest node containing a range index.
+     * @param {int} index Range index of the desired node.
+     * @returns {ASTNode} The node if found or null if not found.
+     */
+    getNodeByRangeIndex(index) {
+        let result = null,
+            resultParent = null;
+        const traverser = new Traverser();
+
+        traverser.traverse(this.ast, {
+            enter(node, parent) {
+                if (node.range[0] <= index && index < node.range[1]) {
+                    result = node;
+                    resultParent = parent;
+                } else {
+                    this.skip();
+                }
+            },
+            leave(node) {
+                if (node === result) {
+                    this.break();
+                }
+            }
+        });
+
+        return result ? Object.assign({ parent: resultParent }, result) : null;
+    },
+
+    /**
+     * Determines if two tokens have at least one whitespace character
+     * between them. This completely disregards comments in making the
+     * determination, so comments count as zero-length substrings.
+     * @param {Token} first The token to check after.
+     * @param {Token} second The token to check before.
+     * @returns {boolean} True if there is only space between tokens, false
+     *  if there is anything other than whitespace between tokens.
+     */
+    isSpaceBetweenTokens(first, second) {
+        const text = this.text.slice(first.range[1], second.range[0]);
+
+        return /\s/.test(text.replace(/\/\*.*?\*\//g, ""));
+    },
+
+    /**
+    * Converts a source text index into a (line, column) pair.
+    * @param {number} index The index of a character in a file
+    * @returns {Object} A {line, column} location object with a 0-indexed column
+    */
+    getLocFromIndex(index) {
+        if (typeof index !== "number") {
+            throw new TypeError("Expected `index` to be a number.");
+        }
+
+        if (index < 0 || index > this.text.length) {
+            throw new RangeError(`Index out of range (requested index ${index}, but source text has length ${this.text.length}).`);
+        }
+
+        /*
+         * For an argument of this.text.length, return the location one "spot" past the last character
+         * of the file. If the last character is a linebreak, the location will be column 0 of the next
+         * line; otherwise, the location will be in the next column on the same line.
+         *
+         * See getIndexFromLoc for the motivation for this special case.
+         */
+        if (index === this.text.length) {
+            return { line: this.lines.length, column: this.lines[this.lines.length - 1].length };
+        }
+
+        /*
+         * To figure out which line rangeIndex is on, determine the last index at which rangeIndex could
+         * be inserted into lineIndices to keep the list sorted.
+         */
+        const lineNumber = lodash.sortedLastIndex(this.lineStartIndices, index);
+
+        return { line: lineNumber, column: index - this.lineStartIndices[lineNumber - 1] };
+
+    },
+
+    /**
+    * Converts a (line, column) pair into a range index.
+    * @param {Object} loc A line/column location
+    * @param {number} loc.line The line number of the location (1-indexed)
+    * @param {number} loc.column The column number of the location (0-indexed)
+    * @returns {number} The range index of the location in the file.
+    */
+    getIndexFromLoc(loc) {
+        if (typeof loc !== "object" || typeof loc.line !== "number" || typeof loc.column !== "number") {
+            throw new TypeError("Expected `loc` to be an object with numeric `line` and `column` properties.");
+        }
+
+        if (loc.line <= 0) {
+            throw new RangeError(`Line number out of range (line ${loc.line} requested). Line numbers should be 1-based.`);
+        }
+
+        if (loc.line > this.lineStartIndices.length) {
+            throw new RangeError(`Line number out of range (line ${loc.line} requested, but only ${this.lineStartIndices.length} lines present).`);
+        }
+
+        const lineStartIndex = this.lineStartIndices[loc.line - 1];
+        const lineEndIndex = loc.line === this.lineStartIndices.length ? this.text.length : this.lineStartIndices[loc.line];
+        const positionIndex = lineStartIndex + loc.column;
+
+        /*
+         * By design, getIndexFromLoc({ line: lineNum, column: 0 }) should return the start index of
+         * the given line, provided that the line number is valid element of this.lines. Since the
+         * last element of this.lines is an empty string for files with trailing newlines, add a
+         * special case where getting the index for the first location after the end of the file
+         * will return the length of the file, rather than throwing an error. This allows rules to
+         * use getIndexFromLoc consistently without worrying about edge cases at the end of a file.
+         */
+        if (
+            loc.line === this.lineStartIndices.length && positionIndex > lineEndIndex ||
+            loc.line < this.lineStartIndices.length && positionIndex >= lineEndIndex
+        ) {
+            throw new RangeError(`Column number out of range (column ${loc.column} requested, but the length of line ${loc.line} is ${lineEndIndex - lineStartIndex}).`);
+        }
+
+        return positionIndex;
+    }
+};
+
+
+module.exports = SourceCode;