fix(coding-agent): stream bash output incrementally (#4165)

fixes #4145
This commit is contained in:
Armin Ronacher
2026-05-04 19:06:07 +02:00
committed by GitHub
parent 3cd1554c8f
commit 6b18cdbac1
3 changed files with 399 additions and 119 deletions

View File

@@ -1,7 +1,4 @@
import { randomBytes } from "node:crypto";
import { createWriteStream, existsSync } from "node:fs";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { existsSync } from "node:fs";
import type { AgentTool } from "@mariozechner/pi-agent-core";
import { Container, Text, truncateToWidth } from "@mariozechner/pi-tui";
import { spawn } from "child_process";
@@ -18,17 +15,10 @@ import {
untrackDetachedChildPid,
} from "../../utils/shell.js";
import type { ToolDefinition, ToolRenderResultOptions } from "../extensions/types.js";
import { OutputAccumulator } from "./output-accumulator.js";
import { getTextOutput, invalidArgText, str } from "./render-utils.js";
import { wrapToolDefinition } from "./tool-definition-wrapper.js";
import { DEFAULT_MAX_BYTES, DEFAULT_MAX_LINES, formatSize, type TruncationResult, truncateTail } from "./truncate.js";
/**
* Generate a unique temp file path for bash output.
*/
function getTempFilePath(): string {
const id = randomBytes(8).toString("hex");
return join(tmpdir(), `pi-bash-${id}.log`);
}
import { DEFAULT_MAX_BYTES, DEFAULT_MAX_LINES, formatSize, type TruncationResult } from "./truncate.js";
const bashSchema = Type.Object({
command: Type.String({ description: "Bash command to execute" }),
@@ -161,6 +151,7 @@ export interface BashToolOptions {
}
const BASH_PREVIEW_LINES = 5;
const BASH_UPDATE_THROTTLE_MS = 100;
type BashRenderState = {
startedAt: number | undefined;
@@ -292,118 +283,119 @@ export function createBashToolDefinition(
) {
const resolvedCommand = commandPrefix ? `${commandPrefix}\n${command}` : command;
const spawnContext = resolveSpawnContext(resolvedCommand, cwd, spawnHook);
const output = new OutputAccumulator({ tempFilePrefix: "pi-bash" });
let updateTimer: NodeJS.Timeout | undefined;
let updateDirty = false;
let lastUpdateAt = 0;
const emitOutputUpdate = () => {
if (!onUpdate || !updateDirty) return;
updateDirty = false;
lastUpdateAt = Date.now();
const snapshot = output.snapshot({ persistIfTruncated: true });
onUpdate({
content: [{ type: "text", text: snapshot.content || "" }],
details: {
truncation: snapshot.truncation.truncated ? snapshot.truncation : undefined,
fullOutputPath: snapshot.fullOutputPath,
},
});
};
const clearUpdateTimer = () => {
if (updateTimer) {
clearTimeout(updateTimer);
updateTimer = undefined;
}
};
const scheduleOutputUpdate = () => {
if (!onUpdate) return;
updateDirty = true;
const delay = BASH_UPDATE_THROTTLE_MS - (Date.now() - lastUpdateAt);
if (delay <= 0) {
clearUpdateTimer();
emitOutputUpdate();
return;
}
updateTimer ??= setTimeout(() => {
updateTimer = undefined;
emitOutputUpdate();
}, delay);
};
if (onUpdate) {
onUpdate({ content: [], details: undefined });
}
return new Promise((resolve, reject) => {
let tempFilePath: string | undefined;
let tempFileStream: ReturnType<typeof createWriteStream> | undefined;
let totalBytes = 0;
const chunks: Buffer[] = [];
let chunksBytes = 0;
const maxChunksBytes = DEFAULT_MAX_BYTES * 2;
const ensureTempFile = () => {
if (tempFilePath) return;
tempFilePath = getTempFilePath();
tempFileStream = createWriteStream(tempFilePath);
for (const chunk of chunks) tempFileStream.write(chunk);
};
const handleData = (data: Buffer) => {
output.append(data);
scheduleOutputUpdate();
};
const handleData = (data: Buffer) => {
totalBytes += data.length;
// Start writing to a temp file once output exceeds the in-memory threshold.
if (totalBytes > DEFAULT_MAX_BYTES) {
ensureTempFile();
}
// Write to temp file if we have one.
if (tempFileStream) tempFileStream.write(data);
// Keep a rolling buffer of recent output for tail truncation.
chunks.push(data);
chunksBytes += data.length;
// Trim old chunks if the rolling buffer grows too large.
while (chunksBytes > maxChunksBytes && chunks.length > 1) {
const removed = chunks.shift()!;
chunksBytes -= removed.length;
}
// Stream partial output using the rolling tail buffer.
if (onUpdate) {
const fullBuffer = Buffer.concat(chunks);
const fullText = fullBuffer.toString("utf-8");
const truncation = truncateTail(fullText);
if (truncation.truncated) {
ensureTempFile();
}
onUpdate({
content: [{ type: "text", text: truncation.content || "" }],
details: {
truncation: truncation.truncated ? truncation : undefined,
fullOutputPath: tempFilePath,
},
});
}
};
const finishOutput = async () => {
output.finish();
clearUpdateTimer();
emitOutputUpdate();
const snapshot = output.snapshot({ persistIfTruncated: true });
await output.closeTempFile();
return snapshot;
};
ops.exec(spawnContext.command, spawnContext.cwd, {
onData: handleData,
signal,
timeout,
env: spawnContext.env,
})
.then(({ exitCode }) => {
// Combine the rolling buffer chunks.
const fullBuffer = Buffer.concat(chunks);
const fullOutput = fullBuffer.toString("utf-8");
// Apply tail truncation for the final display payload.
const truncation = truncateTail(fullOutput);
if (truncation.truncated) {
ensureTempFile();
}
// Close temp file stream before building the final result.
if (tempFileStream) tempFileStream.end();
let outputText = truncation.content || "(no output)";
let details: BashToolDetails | undefined;
if (truncation.truncated) {
// Build truncation details and an actionable notice.
details = { truncation, fullOutputPath: tempFilePath };
const startLine = truncation.totalLines - truncation.outputLines + 1;
const endLine = truncation.totalLines;
if (truncation.lastLinePartial) {
// Edge case: the last line alone is larger than the byte limit.
const lastLineSize = formatSize(Buffer.byteLength(fullOutput.split("\n").pop() || "", "utf-8"));
outputText += `\n\n[Showing last ${formatSize(truncation.outputBytes)} of line ${endLine} (line is ${lastLineSize}). Full output: ${tempFilePath}]`;
} else if (truncation.truncatedBy === "lines") {
outputText += `\n\n[Showing lines ${startLine}-${endLine} of ${truncation.totalLines}. Full output: ${tempFilePath}]`;
} else {
outputText += `\n\n[Showing lines ${startLine}-${endLine} of ${truncation.totalLines} (${formatSize(DEFAULT_MAX_BYTES)} limit). Full output: ${tempFilePath}]`;
}
}
if (exitCode !== 0 && exitCode !== null) {
outputText += `\n\nCommand exited with code ${exitCode}`;
reject(new Error(outputText));
} else {
resolve({ content: [{ type: "text", text: outputText }], details });
}
})
.catch((err: Error) => {
// Close temp file stream and include buffered output in the error message.
if (tempFileStream) tempFileStream.end();
const fullBuffer = Buffer.concat(chunks);
let output = fullBuffer.toString("utf-8");
if (err.message === "aborted") {
if (output) output += "\n\n";
output += "Command aborted";
reject(new Error(output));
} else if (err.message.startsWith("timeout:")) {
const timeoutSecs = err.message.split(":")[1];
if (output) output += "\n\n";
output += `Command timed out after ${timeoutSecs} seconds`;
reject(new Error(output));
} else {
reject(err);
}
const formatOutput = (snapshot: Awaited<ReturnType<typeof finishOutput>>, emptyText = "(no output)") => {
const truncation = snapshot.truncation;
let text = snapshot.content || emptyText;
let details: BashToolDetails | undefined;
if (truncation.truncated) {
details = { truncation, fullOutputPath: snapshot.fullOutputPath };
const startLine = truncation.totalLines - truncation.outputLines + 1;
const endLine = truncation.totalLines;
if (truncation.lastLinePartial) {
const lastLineSize = formatSize(output.getLastLineBytes());
text += `\n\n[Showing last ${formatSize(truncation.outputBytes)} of line ${endLine} (line is ${lastLineSize}). Full output: ${snapshot.fullOutputPath}]`;
} else if (truncation.truncatedBy === "lines") {
text += `\n\n[Showing lines ${startLine}-${endLine} of ${truncation.totalLines}. Full output: ${snapshot.fullOutputPath}]`;
} else {
text += `\n\n[Showing lines ${startLine}-${endLine} of ${truncation.totalLines} (${formatSize(DEFAULT_MAX_BYTES)} limit). Full output: ${snapshot.fullOutputPath}]`;
}
}
return { text, details };
};
const appendStatus = (text: string, status: string) => `${text ? `${text}\n\n` : ""}${status}`;
try {
let exitCode: number | null;
try {
const result = await ops.exec(spawnContext.command, spawnContext.cwd, {
onData: handleData,
signal,
timeout,
env: spawnContext.env,
});
});
exitCode = result.exitCode;
} catch (err) {
const snapshot = await finishOutput();
const { text } = formatOutput(snapshot, "");
if (err instanceof Error && err.message === "aborted") {
throw new Error(appendStatus(text, "Command aborted"));
}
if (err instanceof Error && err.message.startsWith("timeout:")) {
const timeoutSecs = err.message.split(":")[1];
throw new Error(appendStatus(text, `Command timed out after ${timeoutSecs} seconds`));
}
throw err;
}
const snapshot = await finishOutput();
const { text: outputText, details } = formatOutput(snapshot);
if (exitCode !== 0 && exitCode !== null) {
throw new Error(appendStatus(outputText, `Command exited with code ${exitCode}`));
}
return { content: [{ type: "text", text: outputText }], details };
} finally {
clearUpdateTimer();
}
},
renderCall(args, _theme, context) {
const state = context.state;

View File

@@ -0,0 +1,216 @@
import { randomBytes } from "node:crypto";
import { createWriteStream, type WriteStream } from "node:fs";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { DEFAULT_MAX_BYTES, DEFAULT_MAX_LINES, type TruncationResult, truncateTail } from "./truncate.js";
export interface OutputAccumulatorOptions {
maxLines?: number;
maxBytes?: number;
tempFilePrefix?: string;
}
export interface OutputSnapshot {
content: string;
truncation: TruncationResult;
fullOutputPath?: string;
}
function defaultTempFilePath(prefix: string): string {
const id = randomBytes(8).toString("hex");
return join(tmpdir(), `${prefix}-${id}.log`);
}
function byteLength(text: string): number {
return Buffer.byteLength(text, "utf-8");
}
/**
* Incrementally tracks streaming output with bounded memory.
*
* Appends decode chunks with a streaming UTF-8 decoder, keeps only a decoded
* tail for display snapshots, and opens a temp file when the full output needs
* to be preserved.
*/
export class OutputAccumulator {
private readonly maxLines: number;
private readonly maxBytes: number;
private readonly maxRollingBytes: number;
private readonly tempFilePrefix: string;
private readonly decoder = new TextDecoder();
private rawChunks: Buffer[] = [];
private tailText = "";
private tailBytes = 0;
private tailStartsAtLineBoundary = true;
private totalRawBytes = 0;
private totalDecodedBytes = 0;
private totalLines = 1;
private currentLineBytes = 0;
private finished = false;
private tempFilePath: string | undefined;
private tempFileStream: WriteStream | undefined;
constructor(options: OutputAccumulatorOptions = {}) {
this.maxLines = options.maxLines ?? DEFAULT_MAX_LINES;
this.maxBytes = options.maxBytes ?? DEFAULT_MAX_BYTES;
this.maxRollingBytes = Math.max(this.maxBytes * 2, 1);
this.tempFilePrefix = options.tempFilePrefix ?? "pi-output";
}
append(data: Buffer): void {
if (this.finished) {
throw new Error("Cannot append to a finished output accumulator");
}
this.totalRawBytes += data.length;
this.appendDecodedText(this.decoder.decode(data, { stream: true }));
if (this.tempFileStream || this.shouldUseTempFile()) {
this.ensureTempFile();
this.tempFileStream?.write(data);
} else if (data.length > 0) {
this.rawChunks.push(data);
}
}
finish(): void {
if (this.finished) {
return;
}
this.finished = true;
this.appendDecodedText(this.decoder.decode());
if (this.shouldUseTempFile()) {
this.ensureTempFile();
}
}
snapshot(options: { persistIfTruncated?: boolean } = {}): OutputSnapshot {
const tailTruncation = truncateTail(this.getSnapshotText(), {
maxLines: this.maxLines,
maxBytes: this.maxBytes,
});
const truncated = this.totalLines > this.maxLines || this.totalDecodedBytes > this.maxBytes;
const truncatedBy = truncated
? (tailTruncation.truncatedBy ?? (this.totalDecodedBytes > this.maxBytes ? "bytes" : "lines"))
: null;
const truncation: TruncationResult = {
...tailTruncation,
truncated,
truncatedBy,
totalLines: this.totalLines,
totalBytes: this.totalDecodedBytes,
maxLines: this.maxLines,
maxBytes: this.maxBytes,
};
if (options.persistIfTruncated && truncation.truncated) {
this.ensureTempFile();
}
return {
content: truncation.content,
truncation,
fullOutputPath: this.tempFilePath,
};
}
async closeTempFile(): Promise<void> {
if (!this.tempFileStream) {
return;
}
const stream = this.tempFileStream;
this.tempFileStream = undefined;
await new Promise<void>((resolve, reject) => {
const onError = (error: Error) => {
stream.off("finish", onFinish);
reject(error);
};
const onFinish = () => {
stream.off("error", onError);
resolve();
};
stream.once("error", onError);
stream.once("finish", onFinish);
stream.end();
});
}
getLastLineBytes(): number {
return this.currentLineBytes;
}
private appendDecodedText(text: string): void {
if (text.length === 0) {
return;
}
const bytes = byteLength(text);
this.totalDecodedBytes += bytes;
this.tailText += text;
this.tailBytes += bytes;
if (this.tailBytes > this.maxRollingBytes * 2) {
this.trimTail();
}
let newlines = 0;
let lastNewline = -1;
for (let i = text.indexOf("\n"); i !== -1; i = text.indexOf("\n", i + 1)) {
newlines++;
lastNewline = i;
}
if (newlines === 0) {
this.currentLineBytes += bytes;
} else {
this.totalLines += newlines;
this.currentLineBytes = byteLength(text.slice(lastNewline + 1));
}
}
private trimTail(): void {
const buffer = Buffer.from(this.tailText, "utf-8");
if (buffer.length <= this.maxRollingBytes) {
this.tailBytes = buffer.length;
return;
}
let start = buffer.length - this.maxRollingBytes;
while (start < buffer.length && (buffer[start] & 0xc0) === 0x80) {
start++;
}
this.tailStartsAtLineBoundary = start === 0 ? this.tailStartsAtLineBoundary : buffer[start - 1] === 0x0a;
this.tailText = buffer.subarray(start).toString("utf-8");
this.tailBytes = byteLength(this.tailText);
}
private getSnapshotText(): string {
if (this.tailStartsAtLineBoundary) {
return this.tailText;
}
const firstNewline = this.tailText.indexOf("\n");
return firstNewline === -1 ? this.tailText : this.tailText.slice(firstNewline + 1);
}
private shouldUseTempFile(): boolean {
return (
this.totalRawBytes > this.maxBytes || this.totalDecodedBytes > this.maxBytes || this.totalLines > this.maxLines
);
}
private ensureTempFile(): void {
if (this.tempFilePath) {
return;
}
this.tempFilePath = defaultTempFilePath(this.tempFilePrefix);
this.tempFileStream = createWriteStream(this.tempFilePath);
for (const chunk of this.rawChunks) {
this.tempFileStream.write(chunk);
}
this.rawChunks = [];
}
}

View File

@@ -3,7 +3,7 @@ import { tmpdir } from "os";
import { join } from "path";
import { afterEach, beforeEach, describe, expect, it, vi } from "vitest";
import { executeBashWithOperations } from "../src/core/bash-executor.js";
import { createBashTool, createLocalBashOperations } from "../src/core/tools/bash.js";
import { type BashOperations, createBashTool, createLocalBashOperations } from "../src/core/tools/bash.js";
import { computeEditsDiff } from "../src/core/tools/edit-diff.js";
import {
createEditTool,
@@ -449,6 +449,42 @@ describe("Coding Agent Tools", () => {
);
});
it("should include full output path for truncated timeout and abort errors", async () => {
for (const testCase of [
{ error: "timeout:5", expected: "Command timed out after 5 seconds" },
{ error: "aborted", expected: "Command aborted" },
]) {
const operations: BashOperations = {
exec: async (_command, _cwd, { onData }) => {
for (let i = 1; i <= 3000; i++) {
onData(Buffer.from(`${i}\n`, "utf-8"));
}
throw new Error(testCase.error);
},
};
const bash = createBashTool(testDir, { operations });
let error: unknown;
try {
await bash.execute(`test-call-${testCase.error}`, { command: "chatty-fail" });
} catch (err) {
error = err;
}
expect(error).toBeInstanceOf(Error);
const message = (error as Error).message;
expect(message).toContain(testCase.expected);
expect(message).toMatch(/\[Showing lines \d+-\d+ of \d+\. Full output: /);
expect(message).not.toContain("Full output: undefined");
const fullOutputPath = message.match(/Full output: ([^\]\n]+)/)?.[1];
expect(fullOutputPath).toBeDefined();
expect(existsSync(fullOutputPath!)).toBe(true);
const fullOutput = readFileSync(fullOutputPath!, "utf-8");
expect(fullOutput).toContain("1\n2\n3");
expect(fullOutput).toContain("2998\n2999\n3000");
}
});
it("should throw error when cwd does not exist", async () => {
const nonexistentCwd = "/this/directory/definitely/does/not/exist/12345";
@@ -517,6 +553,42 @@ describe("Coding Agent Tools", () => {
expect(getTextOutput(result).trim()).toBe("no-prefix");
});
it("should coalesce streaming updates for chatty output", async () => {
const operations: BashOperations = {
exec: async (_command, _cwd, { onData }) => {
for (let i = 0; i < 5000; i++) {
onData(Buffer.from(`line ${i}\n`, "utf-8"));
}
return { exitCode: 0 };
},
};
const updates: Array<{ content: Array<{ type: string; text?: string }>; details?: unknown }> = [];
const bash = createBashTool(testDir, { operations });
const result = await bash.execute("test-call-chatty-updates", { command: "chatty" }, undefined, (update) =>
updates.push(update),
);
expect(updates.length).toBeLessThan(25);
expect(getTextOutput(result)).toContain("line 4999");
});
it("should decode UTF-8 characters split across output chunks", async () => {
const euro = Buffer.from("€\n", "utf-8");
const operations: BashOperations = {
exec: async (_command, _cwd, { onData }) => {
onData(euro.subarray(0, 1));
onData(euro.subarray(1));
return { exitCode: 0 };
},
};
const bash = createBashTool(testDir, { operations });
const result = await bash.execute("test-call-split-utf8", { command: "split-utf8" });
expect(getTextOutput(result).trim()).toBe("€");
});
it("should expose local bash operations for extension reuse", async () => {
const ops = createLocalBashOperations();
const chunks: Buffer[] = [];