1/** 2 * @fileoverview Helper class to aid in constructing fix commands. 3 * @author Alan Pierce 4 */ 5"use strict"; 6 7//------------------------------------------------------------------------------ 8// Requirements 9//------------------------------------------------------------------------------ 10 11const astUtils = require("./ast-utils"); 12 13//------------------------------------------------------------------------------ 14// Public Interface 15//------------------------------------------------------------------------------ 16 17/** 18 * A helper class to combine fix options into a fix command. Currently, it 19 * exposes some "retain" methods that extend the range of the text being 20 * replaced so that other fixes won't touch that region in the same pass. 21 */ 22class FixTracker { 23 24 /** 25 * Create a new FixTracker. 26 * @param {ruleFixer} fixer A ruleFixer instance. 27 * @param {SourceCode} sourceCode A SourceCode object for the current code. 28 */ 29 constructor(fixer, sourceCode) { 30 this.fixer = fixer; 31 this.sourceCode = sourceCode; 32 this.retainedRange = null; 33 } 34 35 /** 36 * Mark the given range as "retained", meaning that other fixes may not 37 * may not modify this region in the same pass. 38 * @param {int[]} range The range to retain. 39 * @returns {FixTracker} The same RuleFixer, for chained calls. 40 */ 41 retainRange(range) { 42 this.retainedRange = range; 43 return this; 44 } 45 46 /** 47 * Given a node, find the function containing it (or the entire program) and 48 * mark it as retained, meaning that other fixes may not modify it in this 49 * pass. This is useful for avoiding conflicts in fixes that modify control 50 * flow. 51 * @param {ASTNode} node The node to use as a starting point. 52 * @returns {FixTracker} The same RuleFixer, for chained calls. 53 */ 54 retainEnclosingFunction(node) { 55 const functionNode = astUtils.getUpperFunction(node); 56 57 return this.retainRange(functionNode ? functionNode.range : this.sourceCode.ast.range); 58 } 59 60 /** 61 * Given a node or token, find the token before and afterward, and mark that 62 * range as retained, meaning that other fixes may not modify it in this 63 * pass. This is useful for avoiding conflicts in fixes that make a small 64 * change to the code where the AST should not be changed. 65 * @param {ASTNode|Token} nodeOrToken The node or token to use as a starting 66 * point. The token to the left and right are use in the range. 67 * @returns {FixTracker} The same RuleFixer, for chained calls. 68 */ 69 retainSurroundingTokens(nodeOrToken) { 70 const tokenBefore = this.sourceCode.getTokenBefore(nodeOrToken) || nodeOrToken; 71 const tokenAfter = this.sourceCode.getTokenAfter(nodeOrToken) || nodeOrToken; 72 73 return this.retainRange([tokenBefore.range[0], tokenAfter.range[1]]); 74 } 75 76 /** 77 * Create a fix command that replaces the given range with the given text, 78 * accounting for any retained ranges. 79 * @param {int[]} range The range to remove in the fix. 80 * @param {string} text The text to insert in place of the range. 81 * @returns {Object} The fix command. 82 */ 83 replaceTextRange(range, text) { 84 let actualRange; 85 86 if (this.retainedRange) { 87 actualRange = [ 88 Math.min(this.retainedRange[0], range[0]), 89 Math.max(this.retainedRange[1], range[1]) 90 ]; 91 } else { 92 actualRange = range; 93 } 94 95 return this.fixer.replaceTextRange( 96 actualRange, 97 this.sourceCode.text.slice(actualRange[0], range[0]) + 98 text + 99 this.sourceCode.text.slice(range[1], actualRange[1]) 100 ); 101 } 102 103 /** 104 * Create a fix command that removes the given node or token, accounting for 105 * any retained ranges. 106 * @param {ASTNode|Token} nodeOrToken The node or token to remove. 107 * @returns {Object} The fix command. 108 */ 109 remove(nodeOrToken) { 110 return this.replaceTextRange(nodeOrToken.range, ""); 111 } 112} 113 114module.exports = FixTracker; 115