feat(text): expand supported value types

text.go

@@ -5,19 +5,50 @@ import (
 	"io"
 )
 
+// Text is a renderer that writes the given value to the writer as is. It
+// supports rendering the following types as plain text:
+//
+//   - []byte
+//   - []rune
+//   - string
+//   - int, int8, int16, int32, int64
+//   - uint, uint8, uint16, uint32, uint64
+//   - float32, float64
+//   - bool
+//   - io.Reader
+//   - io.WriterTo
+//   - fmt.Stringer
+//   - error
+//
+// If the value is of any other type, a ErrCannotRender error will be returned.
 type Text struct{}
 
 var _ FormatRenderer = (*Text)(nil)
 
+// Render writes the given value to the writer as text.
 func (t *Text) Render(w io.Writer, v any) error {
 	var err error
 	switch x := v.(type) {
-	case fmt.Stringer:
+	case []byte:
-		_, err = w.Write([]byte(x.String()))
+		_, err = w.Write(x)
+	case []rune:
+		_, err = w.Write([]byte(string(x)))
+	case string:
+		_, err = w.Write([]byte(x))
+	case int, int8, int16, int32, int64,
+		uint, uint8, uint16, uint32, uint64,
+		float32, float64, bool:
+		_, err = fmt.Fprintf(w, "%v", x)
+	case io.Reader:
+		_, err = io.Copy(w, x)
 	case io.WriterTo:
 		_, err = x.WriteTo(w)
+	case fmt.Stringer:
+		_, err = w.Write([]byte(x.String()))
+	case error:
+		_, err = w.Write([]byte(x.Error()))
 	default:
-		return ErrCannotRender
+		return fmt.Errorf("%w: %T", ErrCannotRender, v)
 	}
 
 	if err != nil {

text_test.go

@@ -37,6 +37,58 @@ func (m *mockWriterTo) WriteTo(w io.Writer) (int64, error) {
 	return int64(n), err
 }
 
+type mockReader struct {
+	value  string
+	cursor int
+	err    error
+}
+
+var _ io.Reader = (*mockReader)(nil)
+
+func (m *mockReader) Read(p []byte) (n int, err error) {
+	if m.err != nil {
+		return 0, m.err
+	}
+
+	if len(m.value) == 0 {
+		return 0, io.EOF
+	}
+
+	n = copy(p, m.value[m.cursor:])
+	m.cursor += n
+
+	if m.cursor >= len(m.value) {
+		return n, io.EOF
+	}
+
+	return n, nil
+}
+
+func Test_mockReader_Read(t *testing.T) {
+	mr := &mockReader{value: "test string"}
+
+	b1 := make([]byte, 5)
+	n1, err := mr.Read(b1)
+
+	assert.NoError(t, err)
+	assert.Equal(t, 5, n1)
+	assert.Equal(t, "test ", string(b1))
+
+	b2 := make([]byte, 5)
+	n2, err := mr.Read(b2)
+
+	assert.NoError(t, err)
+	assert.Equal(t, 5, n2)
+	assert.Equal(t, "strin", string(b2))
+
+	b3 := make([]byte, 5)
+	n3, err := mr.Read(b3)
+
+	assert.Equal(t, io.EOF, err)
+	assert.Equal(t, 1, n3)
+	assert.Equal(t, []byte{byte('g'), 0, 0, 0, 0}, b3)
+}
+
 func TestText_Render(t *testing.T) {
 	tests := []struct {
 		name      string
@@ -46,6 +98,51 @@ func TestText_Render(t *testing.T) {
 		wantErr   string
 		wantErrIs []error
 	}{
+		{
+			name:      "nil",
+			value:     nil,
+			wantErr:   "render: cannot render: <nil>",
+			wantErrIs: []error{render.Err, render.ErrCannotRender},
+		},
+		{
+			name:  "byte slice",
+			value: []byte("test byte slice"),
+			want:  "test byte slice",
+		},
+		{
+			name:  "nil byte slice",
+			value: []byte(nil),
+			want:  "",
+		},
+		{
+			name:  "empty byte slice",
+			value: []byte{},
+			want:  "",
+		},
+		{
+			name:  "rune slice",
+			value: []rune{'r', 'u', 'n', 'e', 's', '!', ' ', 'y', 'e', 's'},
+			want:  "runes! yes",
+		},
+		{
+			name:  "string",
+			value: "test string",
+			want:  "test string",
+		},
+		{name: "int", value: int(42), want: "42"},
+		{name: "int8", value: int8(43), want: "43"},
+		{name: "int16", value: int16(44), want: "44"},
+		{name: "int32", value: int32(45), want: "45"},
+		{name: "int64", value: int64(46), want: "46"},
+		{name: "uint", value: uint(47), want: "47"},
+		{name: "uint8", value: uint8(48), want: "48"},
+		{name: "uint16", value: uint16(49), want: "49"},
+		{name: "uint32", value: uint32(50), want: "50"},
+		{name: "uint64", value: uint64(51), want: "51"},
+		{name: "float32", value: float32(3.14), want: "3.14"},
+		{name: "float64", value: float64(3.14159), want: "3.14159"},
+		{name: "bool true", value: true, want: "true"},
+		{name: "bool false", value: false, want: "false"},
 		{
 			name:  "implements fmt.Stringer",
 			value: &mockStringer{value: "test string"},
@@ -64,13 +161,7 @@ func TestText_Render(t *testing.T) {
 			want:  "test string",
 		},
 		{
-			name:      "does not implement fmt.Stringer or io.WriterTo",
+			name: "io.WriterTo error",
-			value:     struct{}{},
-			wantErr:   "render: cannot render",
-			wantErrIs: []error{render.Err, render.ErrCannotRender},
-		},
-		{
-			name: "error writing to writer with io.WriterTo",
 			value: &mockWriterTo{
 				value: "test string",
 				err:   errors.New("WriteTo error!!1"),
@@ -78,6 +169,31 @@ func TestText_Render(t *testing.T) {
 			wantErr:   "render: failed: WriteTo error!!1",
 			wantErrIs: []error{render.Err, render.ErrFailed},
 		},
+		{
+			name:  "implements io.Reader",
+			value: &mockReader{value: "reader string"},
+			want:  "reader string",
+		},
+		{
+			name: "io.Reader error",
+			value: &mockReader{
+				value: "reader string",
+				err:   errors.New("Read error!!1"),
+			},
+			wantErr:   "render: failed: Read error!!1",
+			wantErrIs: []error{render.Err, render.ErrFailed},
+		},
+		{
+			name:  "error",
+			value: errors.New("this is an error"),
+			want:  "this is an error",
+		},
+		{
+			name:      "does not implement any supported type/interface",
+			value:     struct{}{},
+			wantErr:   "render: cannot render: struct {}",
+			wantErrIs: []error{render.Err, render.ErrCannotRender},
+		},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
@@ -101,3 +217,7 @@ func TestText_Render(t *testing.T) {
 		})
 	}
 }
+
+func ptr[T any](v T) *T {
+	return &v
+}