searchReplace.ts•4.32 kB
import _ from 'lodash'
import { z } from 'zod'
import env from '../env.js'
import { defineTool } from '../tools.js'
import util from '../util.js'
const CONTEXT_LINES = 2
const ID = 'search_replace'
const searchReplace = defineTool({
id: ID,
name: `${env.OVERRIDE_S_R ? '': 'better_'}${ID}`,
schema: z.object({
file_path: z.string().min(1).describe('Path to the file (supports relative and absolute paths)'),
old_string: z.string().min(1).describe('Exact text to replace (must be unique in file)'),
new_string: z.string().describe('Replacement text'),
allow_multiple_matches: z.boolean().optional().describe('Allow multiple matches to be replaced. If false, throws error when multiple matches found (default: true)'),
}),
description: 'Search and replace with intelligent whitespace handling and automation-friendly multiple match resolution. Tries exact match first, falls back to flexible whitespace matching only when no matches found.',
isReadOnly: false,
isEnabled: env.DEBUG,
fromArgs: ([filePath, oldString, newString]) => ({
file_path: filePath, old_string: oldString, new_string: newString,
}),
handler: (args) => {
const { file_path: filePath, old_string: oldString, new_string: newString, allow_multiple_matches: allowMultiple = true } = args
const fullPath = util.resolve(filePath)
const content = util.readFile(fullPath)
// Validate that the replacement would actually change something
if (oldString.includes(newString)) {
throw new Error(`Redundant replacement: old_string already contains new_string. Old: "${oldString}", New: "${newString}"`)
}
// Core strategies: exact match + whitespace flexibility (matching Cursor's capability)
const patterns = [oldString, createCursorLikePattern(oldString)]
// Try each strategy until one works
for (const pattern of patterns) {
const parts = content.split(pattern)
const matches = parts.length - 1
if (!matches) {
continue
}
if (matches > 1 && !allowMultiple) {
throw new Error(`Multiple matches found (${matches}) for "${oldString}" in ${filePath}. Set allow_multiple_matches=true to allow replacing first occurrence, or make your search string more specific.`)
}
const newContent = parts.join(newString)
util.writeFile(fullPath, newContent)
return formatDiff(content, newContent)
}
throw new Error(`Could not find the specified text in ${filePath}`)
},
})
// Helper function for Cursor-like whitespace handling
function createCursorLikePattern(text: string) {
// Match Cursor's whitespace handling: flexible with spaces/tabs, preserve structure
return new RegExp(_.escapeRegExp(text)
.replace(/\s+/g, '\\s+') // Any whitespace sequence becomes flexible
.replace(/^\s*/, '\\s*') // Optional leading whitespace
.replace(/\s*$/, '\\s*') // Optional trailing whitespace
, 'gm')
}
export default searchReplace
function formatDiff(original: string, updated: string): string {
const originalLines = original.split('\n')
const newLines = updated.split('\n')
// Find the range of lines that changed
let startLine = -1
let endLine = -1
for (let i = 0; i < Math.max(originalLines.length, newLines.length); i++) {
if (originalLines[i] !== newLines[i]) {
if (startLine === -1) startLine = i
endLine = i
}
}
if (startLine === -1) {
throw new Error('Could not generate a diff for changes to the file')
}
// Generate diff with context
const displayStart = Math.max(0, startLine - CONTEXT_LINES)
const displayEnd = Math.min(originalLines.length - 1, endLine + CONTEXT_LINES)
const diffLines: string[] = []
for (let i = displayStart; i <= displayEnd; i++) {
const oldLine = originalLines[i] || ''
const newLine = newLines[i] || ''
if (i < startLine || i > endLine) {
// Context line
diffLines.push(` ${oldLine}`)
} else if (oldLine !== newLine) {
// Changed line
if (oldLine) diffLines.push(`- ${oldLine}`)
if (newLine) diffLines.push(`+ ${newLine}`)
} else {
// Unchanged line within change range
diffLines.push(` ${oldLine}`)
}
}
return `The following diff was applied to the file:
\`\`\`\n${diffLines.join('\n')}\n\`\`\``
}