init project

node_modules/is-stream/index.js

@@ -0,0 +1,37 @@
+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';
+}