conntest: Add 100% coverage

- conntest: Small coherency fixes along the way.
- conntest: Add Discard. Useful for zero filled tests.
- reg: Improve testing.
- CONTRIBUTING.md: fix a typo.

Author: maruel

CONTRIBUTING.md

@@ -1,4 +1,4 @@
 # Contributing
 
-Thanks for contributing to the project! Please look at [periph the
-contribution guidelines](https://periph.io/project/contributing/) first.
+Thanks for contributing to the project! Please look at [the periph contribution
+guidelines](https://periph.io/project/contributing/) first.

conn/conntest/conntest.go

@@ -19,33 +19,23 @@ import (
 type RecordRaw struct {
 	sync.Mutex
 	W io.Writer
-	D conn.Duplex
 }
 
 func (r *RecordRaw) String() string {
 	return "recordraw"
 }
 
-// Write implements conn.Conn.
-func (r *RecordRaw) Write(b []byte) (int, error) {
-	r.Lock()
-	defer r.Unlock()
-	return r.W.Write(b)
-}
-
 // Tx implements conn.Conn.
 func (r *RecordRaw) Tx(w, read []byte) error {
 	if len(read) != 0 {
 		return errors.New("conntest: not implemented")
 	}
-	_, err := r.Write(w)
+	_, err := r.W.Write(w)
 	return err
 }
 
 func (r *RecordRaw) Duplex() conn.Duplex {
-	r.Lock()
-	defer r.Unlock()
-	return r.D
+	return conn.Half
 }
 
 // IO registers the I/O that happened on either a real or fake connection.
@@ -61,21 +51,12 @@ type Record struct {
 	sync.Mutex
 	Conn conn.Conn // Conn can be nil if only writes are being recorded.
 	Ops  []IO
-	D    conn.Duplex
 }
 
 func (r *Record) String() string {
 	return "record"
 }
 
-// Write implements conn.Conn.
-func (r *Record) Write(d []byte) (int, error) {
-	if err := r.Tx(d, nil); err != nil {
-		return 0, err
-	}
-	return len(d), nil
-}
-
 // Tx implements conn.Conn.
 func (r *Record) Tx(w, read []byte) error {
 	r.Lock()
@@ -100,9 +81,10 @@ func (r *Record) Tx(w, read []byte) error {
 }
 
 func (r *Record) Duplex() conn.Duplex {
-	r.Lock()
-	defer r.Unlock()
-	return r.D
+	if r.Conn != nil {
+		return r.Conn.Duplex()
+	}
+	return conn.DuplexUnknown
 }
 
 // Playback implements conn.Conn and plays back a recorded I/O flow.
@@ -119,12 +101,14 @@ func (p *Playback) String() string {
 	return "playback"
 }
 
-// Write implements conn.Conn.
-func (p *Playback) Write(d []byte) (int, error) {
-	if err := p.Tx(d, nil); err != nil {
-		return 0, err
+// Close verifies that all the expected Ops have been consumed.
+func (p *Playback) Close() error {
+	p.Lock()
+	defer p.Unlock()
+	if len(p.Ops) != 0 {
+		return fmt.Errorf("conntest: expected playback to be empty:\n%#v", p.Ops)
 	}
-	return len(d), nil
+	return nil
 }
 
 // Tx implements conn.Conn.
@@ -151,6 +135,29 @@ func (p *Playback) Duplex() conn.Duplex {
 	return p.D
 }
 
+// Discard implements conn.Conn and discards all writes and reads zeros. It
+// never fails.
+type Discard struct {
+	D conn.Duplex
+}
+
+func (d *Discard) String() string {
+	return "discard"
+}
+
+func (d *Discard) Tx(w, r []byte) error {
+	for i := range r {
+		r[i] = 0
+	}
+	return nil
+}
+
+func (d *Discard) Duplex() conn.Duplex {
+	return d.D
+}
+
+//
+
 var _ conn.Conn = &RecordRaw{}
 var _ conn.Conn = &Record{}
 var _ conn.Conn = &Playback{}

conn/conntest/conntest_test.go

@@ -0,0 +1,154 @@
+// Copyright 2017 The Periph Authors. All rights reserved.
+// Use of this source code is governed under the Apache License, Version 2.0
+// that can be found in the LICENSE file.
+
+package conntest
+
+import (
+	"bytes"
+	"testing"
+
+	"periph.io/x/periph/conn"
+)
+
+func TestRecordRaw(t *testing.T) {
+	b := bytes.Buffer{}
+	r := RecordRaw{W: &b}
+	if d := r.Duplex(); d != conn.Half {
+		t.Fatal(d)
+	}
+	if s := r.String(); s != "recordraw" {
+		t.Fatal(s)
+	}
+	if r.Tx(nil, []byte{0}) == nil {
+		t.Fatal("cannot accept read buffer")
+	}
+	if err := r.Tx([]byte{'a'}, nil); err != nil {
+		t.Fatal(err)
+	}
+	if s := b.String(); s != "a" {
+		t.Fatal(s)
+	}
+}
+
+func TestRecord_empty(t *testing.T) {
+	r := Record{}
+	if s := r.String(); s != "record" {
+		t.Fatal(s)
+	}
+	if r.Tx(nil, []byte{'a'}) == nil {
+		t.Fatal("Bus is nil")
+	}
+	if d := r.Duplex(); d != conn.DuplexUnknown {
+		t.Fatal(d)
+	}
+}
+
+func TestRecord_empty_tx(t *testing.T) {
+	r := Record{}
+	if err := r.Tx(nil, nil); err != nil {
+		t.Fatal(err)
+	}
+	if len(r.Ops) != 1 {
+		t.Fatal(r.Ops)
+	}
+	if err := r.Tx([]byte{'a', 'b'}, nil); err != nil {
+		t.Fatal(err)
+	}
+	if len(r.Ops) != 2 {
+		t.Fatal(r.Ops)
+	}
+	if r.Tx([]byte{'a', 'b'}, []byte{'d'}) == nil {
+		t.Fatal("Bus is nil")
+	}
+	if len(r.Ops) != 2 {
+		t.Fatal(r.Ops)
+	}
+}
+
+func TestPlayback(t *testing.T) {
+	p := Playback{}
+	if s := p.String(); s != "playback" {
+		t.Fatal(s)
+	}
+	if err := p.Close(); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestPlayback_tx(t *testing.T) {
+	p := Playback{
+		Ops: []IO{
+			{
+				Write: []byte{10},
+				Read:  []byte{12},
+			},
+		},
+	}
+	if p.Tx(nil, nil) == nil {
+		t.Fatal("missing read and write")
+	}
+	if p.Close() == nil {
+		t.Fatal("Ops is not empty")
+	}
+	v := [1]byte{}
+	if p.Tx([]byte{10}, make([]byte, 2)) == nil {
+		t.Fatal("invalid read size")
+	}
+	if err := p.Tx([]byte{10}, v[:]); err != nil {
+		t.Fatal(err)
+	}
+	if v[0] != 12 {
+		t.Fatalf("expected 12, got %v", v)
+	}
+	if err := p.Tx([]byte{10}, v[:]); err == nil {
+		t.Fatal("Playback.Ops is empty")
+	}
+	if err := p.Close(); err != nil {
+		t.Fatal(err)
+	}
+}
+
+func TestRecord_Playback(t *testing.T) {
+	r := Record{
+		Conn: &Playback{
+			Ops: []IO{
+				{
+					Write: []byte{10},
+					Read:  []byte{12},
+				},
+			},
+			D: conn.Full,
+		},
+	}
+	if d := r.Duplex(); d != conn.Full {
+		t.Fatal(d)
+	}
+
+	v := [1]byte{}
+	if err := r.Tx([]byte{10}, v[:]); err != nil {
+		t.Fatal(err)
+	}
+	if v[0] != 12 {
+		t.Fatalf("expected 12, got %v", v)
+	}
+	if r.Tx([]byte{10}, v[:]) == nil {
+		t.Fatal("Playback.Ops is empty")
+	}
+}
+
+func TestDiscard(t *testing.T) {
+	d := Discard{D: conn.Half}
+	if s := d.String(); s != "discard" {
+		t.Fatal(s)
+	}
+	if v := d.Duplex(); v != conn.Half {
+		t.Fatal(v)
+	}
+	if err := d.Tx(nil, nil); err != nil {
+		t.Fatal(err)
+	}
+	if err := d.Tx([]byte{0}, []byte{0}); err != nil {
+		t.Fatal(err)
+	}
+}