interface StdoutTakeoverState {
rawStdoutWrite: (chunk: string, callback?: (error?: Error | null) => void) => boolean;
rawStderrWrite: (chunk: string, callback?: (error?: Error | null) => void) => boolean;
originalStdoutWrite: typeof process.stdout.write;
}
let stdoutTakeoverState: StdoutTakeoverState | undefined;
export function takeOverStdout(): void {
if (stdoutTakeoverState) {
return;
}
const rawStdoutWrite = process.stdout.write.bind(process.stdout) as StdoutTakeoverState["rawStdoutWrite"];
const rawStderrWrite = process.stderr.write.bind(process.stderr) as StdoutTakeoverState["rawStderrWrite"];
const originalStdoutWrite = process.stdout.write;
process.stdout.write = ((
chunk: string | Uint8Array,
encodingOrCallback?: BufferEncoding | ((error?: Error | null) => void),
callback?: (error?: Error | null) => void,
): boolean => {
if (typeof encodingOrCallback === "function") {
return rawStderrWrite(String(chunk), encodingOrCallback);
}
return rawStderrWrite(String(chunk), callback);
}) as typeof process.stdout.write;
stdoutTakeoverState = {
rawStdoutWrite,
rawStderrWrite,
originalStdoutWrite,
};
}
export function restoreStdout(): void {
if (!stdoutTakeoverState) {
return;
}
process.stdout.write = stdoutTakeoverState.originalStdoutWrite;
stdoutTakeoverState = undefined;
}
export function isStdoutTakenOver(): boolean {
return stdoutTakeoverState !== undefined;
}
export function writeRawStdout(text: string): void {
if (stdoutTakeoverState) {
stdoutTakeoverState.rawStdoutWrite(text);
return;
}
process.stdout.write(text);
}
export async function flushRawStdout(): Promise<void> {
if (stdoutTakeoverState) {
await new Promise<void>((resolve, reject) => {
stdoutTakeoverState?.rawStdoutWrite("", (err) => {
if (err) reject(err);
else resolve();
});
});
return;
}
await new Promise<void>((resolve, reject) => {
process.stdout.write("", (err) => {
if (err) reject(err);
else resolve();
});
});
}