add unit test for attrs

Author: Richard Patel

attrs.go

@@ -1,9 +1,25 @@
+//  Copyright 2022 Blockdaemon Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
 package pyth
 
 import (
 	"bytes"
 	"fmt"
 	"io"
+	"sort"
+	"strings"
 )
 
 // AttrsMap is a list of string key-value pairs with stable order.
@@ -24,6 +40,7 @@ func NewAttrsMap(fromGo map[string]string) (out AttrsMap, err error) {
 		}
 		out.Pairs = append(out.Pairs, [2]string{k, v})
 	}
+	out.Sort()
 	return
 }
 
@@ -36,6 +53,13 @@ func (a AttrsMap) KVs() map[string]string {
 	return m
 }
 
+// Sort sorts the keys of an AttrsMap by lexicographic order.
+func (a AttrsMap) Sort() {
+	sort.Slice(a.Pairs, func(i, j int) bool {
+		return strings.Compare(a.Pairs[i][0], a.Pairs[j][0]) < 0
+	})
+}
+
 // UnmarshalBinary unmarshals AttrsMap from its on-chain format.
 //
 // Will return an error if it fails to consume the entire provided byte slice.

attrs_test.go

@@ -0,0 +1,69 @@
+//  Copyright 2022 Blockdaemon Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package pyth
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestAttrsMap(t *testing.T) {
+	caseMap := map[string]string{
+		"1pythians":   "are",
+		"2incredibly": "based",
+	}
+	attrs, err := NewAttrsMap(caseMap)
+	require.NoError(t, err)
+	assert.Equal(t, [][2]string{
+		{"1pythians", "are"},
+		{"2incredibly", "based"},
+	}, attrs.Pairs)
+	assert.Equal(t, caseMap, attrs.KVs())
+
+	buf, err := attrs.MarshalBinary()
+	require.NoError(t, err)
+	assert.Equal(t, []byte(
+		"\x09"+"1pythians"+"\x03"+"are"+
+			"\x0b"+"2incredibly"+"\x05"+"based",
+	), buf)
+
+	var attrs2 AttrsMap
+	require.NoError(t, attrs2.UnmarshalBinary(buf))
+	assert.Equal(t, attrs, attrs2)
+}
+
+func TestAttrsMap_LongKey(t *testing.T) {
+	longKey := strings.Repeat("A", 256)
+	caseMap := map[string]string{
+		longKey: ":)",
+	}
+	attrs, err := NewAttrsMap(caseMap)
+	assert.EqualError(t, err, `key too long (256 > 0xFF): "`+longKey+`"`)
+	assert.Len(t, attrs.Pairs, 0)
+	assert.Len(t, attrs.KVs(), 0)
+}
+
+func TestAttrsMap_LongValue(t *testing.T) {
+	caseMap := map[string]string{
+		"bla": strings.Repeat("A", 256),
+	}
+	attrs, err := NewAttrsMap(caseMap)
+	assert.EqualError(t, err, `value too long (256 > 0xFF): "`+caseMap["bla"]+`"`)
+	assert.Len(t, attrs.Pairs, 0)
+	assert.Len(t, attrs.KVs(), 0)
+}