index.js•1.33 kB
export function isStream(stream, {checkOpen = true} = {}) {
return stream !== null
&& typeof stream === 'object'
&& (stream.writable || stream.readable || !checkOpen || (stream.writable === undefined && stream.readable === undefined))
&& typeof stream.pipe === 'function';
}
export function isWritableStream(stream, {checkOpen = true} = {}) {
return isStream(stream, {checkOpen})
&& (stream.writable || !checkOpen)
&& typeof stream.write === 'function'
&& typeof stream.end === 'function'
&& typeof stream.writable === 'boolean'
&& typeof stream.writableObjectMode === 'boolean'
&& typeof stream.destroy === 'function'
&& typeof stream.destroyed === 'boolean';
}
export function isReadableStream(stream, {checkOpen = true} = {}) {
return isStream(stream, {checkOpen})
&& (stream.readable || !checkOpen)
&& typeof stream.read === 'function'
&& typeof stream.readable === 'boolean'
&& typeof stream.readableObjectMode === 'boolean'
&& typeof stream.destroy === 'function'
&& typeof stream.destroyed === 'boolean';
}
export function isDuplexStream(stream, options) {
return isWritableStream(stream, options)
&& isReadableStream(stream, options);
}
export function isTransformStream(stream, options) {
return isDuplexStream(stream, options)
&& typeof stream._transform === 'function';
}