import { spawn } from "node:child_process"; export interface ProcessRunOptions { cwd?: string | undefined; timeoutMs?: number | undefined; env?: NodeJS.ProcessEnv | undefined; stdin?: string | undefined; allowNonZeroExit?: boolean | undefined; maxBufferBytes?: number | undefined; outputMode?: "error" | "truncate" | undefined;} export interface ProcessRunResult { stdout: string; stderr: string; code: number | null; signal: NodeJS.Signals | null; timedOut: boolean; stdoutTruncated?: boolean | undefined; stderrTruncated?: boolean | undefined;} function commandLabel(command: string, args: readonly string[]): string { return [command, ...args].join(" ");} function normalizeSpawnError(command: string, args: readonly string[], error: unknown): Error { if (!(error instanceof Error)) { return new Error(`Failed to run ${commandLabel(command, args)}.`); } const maybeCode = (error as NodeJS.ErrnoException).code; if (maybeCode === "ENOENT") { return new Error(`Command not found: ${command}`); } return new Error(`Failed to run ${commandLabel(command, args)}: ${error.message}`);} function normalizeExitError( command: string, args: readonly string[], result: ProcessRunResult,): Error { const reason = result.timedOut ? "timed out" : `failed (code=${result.code ?? "null"}, signal=${result.signal ?? "null"})`; const stderr = result.stderr.trim(); const detail = stderr.length > 0 ? ` ${stderr}` : ""; return new Error(`${commandLabel(command, args)} ${reason}.${detail}`);} function normalizeStdinError(command: string, args: readonly string[], error: unknown): Error { if (!(error instanceof Error)) { return new Error(`Failed to write stdin for ${commandLabel(command, args)}.`); } return new Error(`Failed to write stdin for ${commandLabel(command, args)}: ${error.message}`);} function normalizeBufferError( command: string, args: readonly string[], stream: "stdout" | "stderr", maxBufferBytes: number,): Error { return new Error( `${commandLabel(command, args)} exceeded ${stream} buffer limit (${maxBufferBytes} bytes).`, );} const DEFAULT_MAX_BUFFER_BYTES = 8 * 1024 * 1024; function appendChunkWithinLimit( target: string, currentBytes: number, chunk: Buffer, maxBytes: number,): { next: string; nextBytes: number; truncated: boolean;} { const remaining = maxBytes - currentBytes; if (remaining <= 0) { return { next: target, nextBytes: currentBytes, truncated: true }; } if (chunk.length <= remaining) { return { next: `${target}${chunk.toString()}`, nextBytes: currentBytes + chunk.length, truncated: false, }; } return { next: `${target}${chunk.subarray(0, remaining).toString()}`, nextBytes: currentBytes + remaining, truncated: true, };} export async function runProcess( command: string, args: readonly string[], options: ProcessRunOptions = {},): Promise<ProcessRunResult> { const timeoutMs = options.timeoutMs ?? 60_000; const maxBufferBytes = options.maxBufferBytes ?? DEFAULT_MAX_BUFFER_BYTES; const outputMode = options.outputMode ?? "error"; return new Promise<ProcessRunResult>((resolve, reject) => { const child = spawn(command, args, { cwd: options.cwd, env: options.env, stdio: "pipe", }); let stdout = ""; let stderr = ""; let stdoutBytes = 0; let stderrBytes = 0; let stdoutTruncated = false; let stderrTruncated = false; let timedOut = false; let settled = false; let forceKillTimer: ReturnType<typeof setTimeout> | null = null; const timeoutTimer = setTimeout(() => { timedOut = true; child.kill("SIGTERM"); forceKillTimer = setTimeout(() => { child.kill("SIGKILL"); }, 1_000); }, timeoutMs); const finalize = (callback: () => void): void => { if (settled) return; settled = true; clearTimeout(timeoutTimer); if (forceKillTimer) { clearTimeout(forceKillTimer); } callback(); }; const fail = (error: Error): void => { child.kill("SIGTERM"); finalize(() => { reject(error); }); }; const appendOutput = (stream: "stdout" | "stderr", chunk: Buffer | string): Error | null => { const chunkBuffer = typeof chunk === "string" ? Buffer.from(chunk) : chunk; const text = chunkBuffer.toString(); const byteLength = chunkBuffer.length; if (stream === "stdout") { if (outputMode === "truncate") { const appended = appendChunkWithinLimit(stdout, stdoutBytes, chunkBuffer, maxBufferBytes); stdout = appended.next; stdoutBytes = appended.nextBytes; stdoutTruncated = stdoutTruncated || appended.truncated; return null; } stdout += text; stdoutBytes += byteLength; if (stdoutBytes > maxBufferBytes) { return normalizeBufferError(command, args, "stdout", maxBufferBytes); } } else { if (outputMode === "truncate") { const appended = appendChunkWithinLimit(stderr, stderrBytes, chunkBuffer, maxBufferBytes); stderr = appended.next; stderrBytes = appended.nextBytes; stderrTruncated = stderrTruncated || appended.truncated; return null; } stderr += text; stderrBytes += byteLength; if (stderrBytes > maxBufferBytes) { return normalizeBufferError(command, args, "stderr", maxBufferBytes); } } return null; }; child.stdout.on("data", (chunk: Buffer | string) => { const error = appendOutput("stdout", chunk); if (error) { fail(error); } }); child.stderr.on("data", (chunk: Buffer | string) => { const error = appendOutput("stderr", chunk); if (error) { fail(error); } }); child.once("error", (error) => { finalize(() => { reject(normalizeSpawnError(command, args, error)); }); }); child.once("close", (code, signal) => { const result: ProcessRunResult = { stdout, stderr, code, signal, timedOut, stdoutTruncated, stderrTruncated, }; finalize(() => { if (!options.allowNonZeroExit && (timedOut || (code !== null && code !== 0))) { reject(normalizeExitError(command, args, result)); return; } resolve(result); }); }); child.stdin.once("error", (error) => { fail(normalizeStdinError(command, args, error)); }); if (options.stdin !== undefined) { child.stdin.write(options.stdin, (error) => { if (error) { fail(normalizeStdinError(command, args, error)); return; } child.stdin.end(); }); return; } child.stdin.end(); });}
import { spawn } from "node:child_process";
export interface ProcessRunOptions {
cwd?: string | undefined;
timeoutMs?: number | undefined;
env?: NodeJS.ProcessEnv | undefined;
stdin?: string | undefined;
allowNonZeroExit?: boolean | undefined;
maxBufferBytes?: number | undefined;
outputMode?: "error" | "truncate" | undefined;
}
export interface ProcessRunResult {
stdout: string;
stderr: string;
code: number | null;
signal: NodeJS.Signals | null;
timedOut: boolean;
stdoutTruncated?: boolean | undefined;
stderrTruncated?: boolean | undefined;
}
function commandLabel(command: string, args: readonly string[]): string {
return [command, ...args].join(" ");
}
function normalizeSpawnError(command: string, args: readonly string[], error: unknown): Error {
if (!(error instanceof Error)) {
return new Error(`Failed to run ${commandLabel(command, args)}.`);
}
const maybeCode = (error as NodeJS.ErrnoException).code;
if (maybeCode === "ENOENT") {
return new Error(`Command not found: ${command}`);
}
return new Error(`Failed to run ${commandLabel(command, args)}: ${error.message}`);
}
function normalizeExitError(
command: string,
args: readonly string[],
result: ProcessRunResult,
): Error {
const reason = result.timedOut
? "timed out"
: `failed (code=${result.code ?? "null"}, signal=${result.signal ?? "null"})`;
const stderr = result.stderr.trim();
const detail = stderr.length > 0 ? ` ${stderr}` : "";
return new Error(`${commandLabel(command, args)} ${reason}.${detail}`);
}
function normalizeStdinError(command: string, args: readonly string[], error: unknown): Error {
if (!(error instanceof Error)) {
return new Error(`Failed to write stdin for ${commandLabel(command, args)}.`);
}
return new Error(`Failed to write stdin for ${commandLabel(command, args)}: ${error.message}`);
}
function normalizeBufferError(
command: string,
args: readonly string[],
stream: "stdout" | "stderr",
maxBufferBytes: number,
): Error {
return new Error(
`${commandLabel(command, args)} exceeded ${stream} buffer limit (${maxBufferBytes} bytes).`,
);
}
const DEFAULT_MAX_BUFFER_BYTES = 8 * 1024 * 1024;
function appendChunkWithinLimit(
target: string,
currentBytes: number,
chunk: Buffer,
maxBytes: number,
): {
next: string;
nextBytes: number;
truncated: boolean;
} {
const remaining = maxBytes - currentBytes;
if (remaining <= 0) {
return { next: target, nextBytes: currentBytes, truncated: true };
}
if (chunk.length <= remaining) {
return {
next: `${target}${chunk.toString()}`,
nextBytes: currentBytes + chunk.length,
truncated: false,
};
}
return {
next: `${target}${chunk.subarray(0, remaining).toString()}`,
nextBytes: currentBytes + remaining,
truncated: true,
};
}
export async function runProcess(
command: string,
args: readonly string[],
options: ProcessRunOptions = {},
): Promise<ProcessRunResult> {
const timeoutMs = options.timeoutMs ?? 60_000;
const maxBufferBytes = options.maxBufferBytes ?? DEFAULT_MAX_BUFFER_BYTES;
const outputMode = options.outputMode ?? "error";
return new Promise<ProcessRunResult>((resolve, reject) => {
const child = spawn(command, args, {
cwd: options.cwd,
env: options.env,
stdio: "pipe",
});
let stdout = "";
let stderr = "";
let stdoutBytes = 0;
let stderrBytes = 0;
let stdoutTruncated = false;
let stderrTruncated = false;
let timedOut = false;
let settled = false;
let forceKillTimer: ReturnType<typeof setTimeout> | null = null;
const timeoutTimer = setTimeout(() => {
timedOut = true;
child.kill("SIGTERM");
forceKillTimer = setTimeout(() => {
child.kill("SIGKILL");
}, 1_000);
}, timeoutMs);
const finalize = (callback: () => void): void => {
if (settled) return;
settled = true;
clearTimeout(timeoutTimer);
if (forceKillTimer) {
clearTimeout(forceKillTimer);
}
callback();
};
const fail = (error: Error): void => {
child.kill("SIGTERM");
finalize(() => {
reject(error);
});
};
const appendOutput = (stream: "stdout" | "stderr", chunk: Buffer | string): Error | null => {
const chunkBuffer = typeof chunk === "string" ? Buffer.from(chunk) : chunk;
const text = chunkBuffer.toString();
const byteLength = chunkBuffer.length;
if (stream === "stdout") {
if (outputMode === "truncate") {
const appended = appendChunkWithinLimit(stdout, stdoutBytes, chunkBuffer, maxBufferBytes);
stdout = appended.next;
stdoutBytes = appended.nextBytes;
stdoutTruncated = stdoutTruncated || appended.truncated;
return null;
}
stdout += text;
stdoutBytes += byteLength;
if (stdoutBytes > maxBufferBytes) {
return normalizeBufferError(command, args, "stdout", maxBufferBytes);
}
} else {
if (outputMode === "truncate") {
const appended = appendChunkWithinLimit(stderr, stderrBytes, chunkBuffer, maxBufferBytes);
stderr = appended.next;
stderrBytes = appended.nextBytes;
stderrTruncated = stderrTruncated || appended.truncated;
return null;
}
stderr += text;
stderrBytes += byteLength;
if (stderrBytes > maxBufferBytes) {
return normalizeBufferError(command, args, "stderr", maxBufferBytes);
}
}
return null;
};
child.stdout.on("data", (chunk: Buffer | string) => {
const error = appendOutput("stdout", chunk);
if (error) {
fail(error);
}
});
child.stderr.on("data", (chunk: Buffer | string) => {
const error = appendOutput("stderr", chunk);
if (error) {
fail(error);
}
});
child.once("error", (error) => {
finalize(() => {
reject(normalizeSpawnError(command, args, error));
});
});
child.once("close", (code, signal) => {
const result: ProcessRunResult = {
stdout,
stderr,
code,
signal,
timedOut,
stdoutTruncated,
stderrTruncated,
};
finalize(() => {
if (!options.allowNonZeroExit && (timedOut || (code !== null && code !== 0))) {
reject(normalizeExitError(command, args, result));
return;
}
resolve(result);
});
});
child.stdin.once("error", (error) => {
fail(normalizeStdinError(command, args, error));
});
if (options.stdin !== undefined) {
child.stdin.write(options.stdin, (error) => {
if (error) {
fail(normalizeStdinError(command, args, error));
return;
}
child.stdin.end();
});
return;
}
child.stdin.end();
});
}