Show edit diff before tool execution (fixes #393)

- Extract diff computation from edit.ts into shared edit-diff.ts
- ToolExecutionComponent computes and caches diff when args are complete
- Diff is visible while permission hooks block, before tool executes
This commit is contained in:
Mario Zechner 2026-01-01 20:34:19 +01:00
parent 173b81bc04
commit 1ed009e2cf
4 changed files with 277 additions and 134 deletions

View file

@ -1,132 +1,10 @@
import type { AgentTool } from "@mariozechner/pi-agent-core";
import { Type } from "@sinclair/typebox";
import * as Diff from "diff";
import { constants } from "fs";
import { access, readFile, writeFile } from "fs/promises";
import { detectLineEnding, generateDiffString, normalizeToLF, restoreLineEndings } from "./edit-diff.js";
import { resolveToCwd } from "./path-utils.js";
function detectLineEnding(content: string): "\r\n" | "\n" {
const crlfIdx = content.indexOf("\r\n");
const lfIdx = content.indexOf("\n");
if (lfIdx === -1) return "\n";
if (crlfIdx === -1) return "\n";
return crlfIdx < lfIdx ? "\r\n" : "\n";
}
function normalizeToLF(text: string): string {
return text.replace(/\r\n/g, "\n").replace(/\r/g, "\n");
}
function restoreLineEndings(text: string, ending: "\r\n" | "\n"): string {
return ending === "\r\n" ? text.replace(/\n/g, "\r\n") : text;
}
/**
* Generate a unified diff string with line numbers and context
* Returns both the diff string and the first changed line number (in the new file)
*/
function generateDiffString(
oldContent: string,
newContent: string,
contextLines = 4,
): { diff: string; firstChangedLine: number | undefined } {
const parts = Diff.diffLines(oldContent, newContent);
const output: string[] = [];
const oldLines = oldContent.split("\n");
const newLines = newContent.split("\n");
const maxLineNum = Math.max(oldLines.length, newLines.length);
const lineNumWidth = String(maxLineNum).length;
let oldLineNum = 1;
let newLineNum = 1;
let lastWasChange = false;
let firstChangedLine: number | undefined;
for (let i = 0; i < parts.length; i++) {
const part = parts[i];
const raw = part.value.split("\n");
if (raw[raw.length - 1] === "") {
raw.pop();
}
if (part.added || part.removed) {
// Capture the first changed line (in the new file)
if (firstChangedLine === undefined) {
firstChangedLine = newLineNum;
}
// Show the change
for (const line of raw) {
if (part.added) {
const lineNum = String(newLineNum).padStart(lineNumWidth, " ");
output.push(`+${lineNum} ${line}`);
newLineNum++;
} else {
// removed
const lineNum = String(oldLineNum).padStart(lineNumWidth, " ");
output.push(`-${lineNum} ${line}`);
oldLineNum++;
}
}
lastWasChange = true;
} else {
// Context lines - only show a few before/after changes
const nextPartIsChange = i < parts.length - 1 && (parts[i + 1].added || parts[i + 1].removed);
if (lastWasChange || nextPartIsChange) {
// Show context
let linesToShow = raw;
let skipStart = 0;
let skipEnd = 0;
if (!lastWasChange) {
// Show only last N lines as leading context
skipStart = Math.max(0, raw.length - contextLines);
linesToShow = raw.slice(skipStart);
}
if (!nextPartIsChange && linesToShow.length > contextLines) {
// Show only first N lines as trailing context
skipEnd = linesToShow.length - contextLines;
linesToShow = linesToShow.slice(0, contextLines);
}
// Add ellipsis if we skipped lines at start
if (skipStart > 0) {
output.push(` ${"".padStart(lineNumWidth, " ")} ...`);
// Update line numbers for the skipped leading context
oldLineNum += skipStart;
newLineNum += skipStart;
}
for (const line of linesToShow) {
const lineNum = String(oldLineNum).padStart(lineNumWidth, " ");
output.push(` ${lineNum} ${line}`);
oldLineNum++;
newLineNum++;
}
// Add ellipsis if we skipped lines at end
if (skipEnd > 0) {
output.push(` ${"".padStart(lineNumWidth, " ")} ...`);
// Update line numbers for the skipped trailing context
oldLineNum += skipEnd;
newLineNum += skipEnd;
}
} else {
// Skip these context lines entirely
oldLineNum += raw.length;
newLineNum += raw.length;
}
lastWasChange = false;
}
}
return { diff: output.join("\n"), firstChangedLine };
}
const editSchema = Type.Object({
path: Type.String({ description: "Path to the file to edit (relative or absolute)" }),
oldText: Type.String({ description: "Exact text to find and replace (must match exactly)" }),