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2 years ago
/**
* @fileoverview Helper class to aid in constructing fix commands.
* @author Alan Pierce
*/
"use strict";
//------------------------------------------------------------------------------
// Requirements
//------------------------------------------------------------------------------
const astUtils = require("./ast-utils");
//------------------------------------------------------------------------------
// Public Interface
//------------------------------------------------------------------------------
/**
* A helper class to combine fix options into a fix command. Currently, it
* exposes some "retain" methods that extend the range of the text being
* replaced so that other fixes won't touch that region in the same pass.
*/
class FixTracker {
/**
* Create a new FixTracker.
* @param {ruleFixer} fixer A ruleFixer instance.
* @param {SourceCode} sourceCode A SourceCode object for the current code.
*/
constructor(fixer, sourceCode) {
this.fixer = fixer;
this.sourceCode = sourceCode;
this.retainedRange = null;
}
/**
* Mark the given range as "retained", meaning that other fixes may not
* may not modify this region in the same pass.
* @param {int[]} range The range to retain.
* @returns {FixTracker} The same RuleFixer, for chained calls.
*/
retainRange(range) {
this.retainedRange = range;
return this;
}
/**
* Given a node, find the function containing it (or the entire program) and
* mark it as retained, meaning that other fixes may not modify it in this
* pass. This is useful for avoiding conflicts in fixes that modify control
* flow.
* @param {ASTNode} node The node to use as a starting point.
* @returns {FixTracker} The same RuleFixer, for chained calls.
*/
retainEnclosingFunction(node) {
const functionNode = astUtils.getUpperFunction(node);
return this.retainRange(functionNode ? functionNode.range : this.sourceCode.ast.range);
}
/**
* Given a node or token, find the token before and afterward, and mark that
* range as retained, meaning that other fixes may not modify it in this
* pass. This is useful for avoiding conflicts in fixes that make a small
* change to the code where the AST should not be changed.
* @param {ASTNode|Token} nodeOrToken The node or token to use as a starting
* point. The token to the left and right are use in the range.
* @returns {FixTracker} The same RuleFixer, for chained calls.
*/
retainSurroundingTokens(nodeOrToken) {
const tokenBefore = this.sourceCode.getTokenBefore(nodeOrToken) || nodeOrToken;
const tokenAfter = this.sourceCode.getTokenAfter(nodeOrToken) || nodeOrToken;
return this.retainRange([tokenBefore.range[0], tokenAfter.range[1]]);
}
/**
* Create a fix command that replaces the given range with the given text,
* accounting for any retained ranges.
* @param {int[]} range The range to remove in the fix.
* @param {string} text The text to insert in place of the range.
* @returns {Object} The fix command.
*/
replaceTextRange(range, text) {
let actualRange;
if (this.retainedRange) {
actualRange = [
Math.min(this.retainedRange[0], range[0]),
Math.max(this.retainedRange[1], range[1])
];
} else {
actualRange = range;
}
return this.fixer.replaceTextRange(
actualRange,
this.sourceCode.text.slice(actualRange[0], range[0]) +
text +
this.sourceCode.text.slice(range[1], actualRange[1])
);
}
/**
* Create a fix command that removes the given node or token, accounting for
* any retained ranges.
* @param {ASTNode|Token} nodeOrToken The node or token to remove.
* @returns {Object} The fix command.
*/
remove(nodeOrToken) {
return this.replaceTextRange(nodeOrToken.range, "");
}
}
module.exports = FixTracker;