Initial project import

tools/v/vlib/io/multi_writer_test.v

@@ -0,0 +1,49 @@
+module io
+
+fn test_multi_writer_write_successful() {
+	mut mw := new_multi_writer(&TestWriter{}, &TestWriter{})
+	n := mw.write('0123456789'.bytes()) or {
+		assert false
+		return
+	}
+	assert n == 10
+}
+
+fn test_multi_writer_write_incomplete() {
+	mut mw := new_multi_writer(&TestWriter{}, &TestIncompleteWriter{})
+	_ := mw.write('0123456789'.bytes()) or { return }
+	assert false
+}
+
+fn test_multi_writer_write_error() {
+	mut mw := new_multi_writer(&TestWriter{}, &TestErrorWriter{}, &TestWriter{})
+	_ := mw.write('0123456789'.bytes()) or { return }
+	assert false
+}
+
+struct TestWriter {
+pub mut:
+	bytes []u8
+}
+
+fn (mut w TestWriter) write(buf []u8) !int {
+	w.bytes << buf
+	return buf.len
+}
+
+struct TestIncompleteWriter {
+pub mut:
+	bytes []u8
+}
+
+fn (mut w TestIncompleteWriter) write(buf []u8) !int {
+	b := buf[..buf.len - 1]
+	w.bytes << b
+	return b.len
+}
+
+struct TestErrorWriter {}
+
+fn (mut w TestErrorWriter) write(buf []u8) !int {
+	return error('error writer errored')
+}