Add StringMap type (#97)

Author: peterklijn

README.md

@@ -45,6 +45,7 @@ The fields have to be one of the types that the sync package supports in order t
 - sync.Bool, allows for concurrent bool manipulation
 - sync.Secret, allows for concurrent secret manipulation. Secrets can only be strings
 - sync.TimeDuration, allows for concurrent time.duration manipulation.
+- sync.StringMap, allows for concurrent map[string]string manipulation.
 
 For sensitive configuration (passwords, tokens, etc.) that shouldn't be printed in log, you can use the `Secret` flavor of `sync` types. If one of these is selected, then at harvester log instead of the real value the text `***` will be displayed.
 

sync/sync.go

@@ -2,8 +2,10 @@
 package sync
 
 import (
+	"bytes"
 	"fmt"
 	"strconv"
+	"strings"
 	"sync"
 	"time"
 )
@@ -222,3 +224,55 @@ func (s *Secret) SetString(val string) error {
 	s.Set(val)
 	return nil
 }
+
+// StringMap is a map[string]string type with concurrent access support.
+type StringMap struct {
+	rw    sync.RWMutex
+	value map[string]string
+}
+
+// Get returns the internal value.
+func (s *StringMap) Get() map[string]string {
+	s.rw.RLock()
+	defer s.rw.RUnlock()
+	return s.value
+}
+
+// Set a value.
+func (s *StringMap) Set(value map[string]string) {
+	s.rw.Lock()
+	defer s.rw.Unlock()
+	s.value = value
+}
+
+// String returns a string representation of the value.
+func (s *StringMap) String() string {
+	s.rw.RLock()
+	defer s.rw.RUnlock()
+	b := new(bytes.Buffer)
+	firstChar := ""
+	for key, value := range s.value {
+		_, _ = fmt.Fprintf(b, "%s%s=%q", firstChar, key, value)
+		firstChar = ","
+	}
+	return b.String()
+}
+
+// SetString parses and sets a value from string type.
+func (s *StringMap) SetString(val string) error {
+	dict := make(map[string]string)
+	if val == "" || strings.TrimSpace(val) == "" {
+		s.Set(dict)
+		return nil
+	}
+	for _, pair := range strings.Split(val, ",") {
+		items := strings.SplitN(pair, ":", 2)
+		if len(items) != 2 {
+			return fmt.Errorf("map must be formatted as `key:value`, got %q", pair)
+		}
+		key, value := strings.TrimSpace(items[0]), strings.TrimSpace(items[1])
+		dict[key] = value
+	}
+	s.Set(dict)
+	return nil
+}

sync/sync_test.go

@@ -119,3 +119,55 @@ func TestTimeDuration_SetString(t *testing.T) {
 	assert.NoError(t, f.SetString("3s"))
 	assert.Equal(t, 3*time.Second, f.Get())
 }
+
+func TestStringMap(t *testing.T) {
+	var sm StringMap
+	ch := make(chan struct{})
+	go func() {
+		sm.Set(map[string]string{"key": "value"})
+		ch <- struct{}{}
+	}()
+	<-ch
+	assert.Equal(t, map[string]string{"key": "value"}, sm.Get())
+	assert.Equal(t, "key=\"value\"", sm.String())
+}
+
+func TestStringMap_SetString(t *testing.T) {
+	tests := []struct {
+		name        string
+		input       string
+		result      map[string]string
+		throwsError bool
+	}{
+		{"empty", "", map[string]string{}, false},
+		{"empty with spaces", "   ", map[string]string{}, false},
+		{"single item", "key:value", map[string]string{"key": "value"}, false},
+		{"single item with route as val", "key:http://thing", map[string]string{"key": "http://thing"}, false},
+		{"key without value", "key", nil, true},
+		{"multiple items", "key1:value,key2:value", map[string]string{"key1": "value", "key2": "value"}, false},
+		{"multiple items with spaces", " key1 : value , key2 :value ", map[string]string{"key1": "value", "key2": "value"}, false},
+		{"multiple urls", "key1:http://one,key2:https://two", map[string]string{"key1": "http://one", "key2": "https://two"}, false},
+	}
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			sm := StringMap{}
+
+			err := sm.SetString(test.input)
+			if test.throwsError {
+				assert.Error(t, err)
+			}
+
+			assert.Equal(t, test.result, sm.Get())
+		})
+	}
+}
+
+func TestStringMap_SetString_DoesntOverrideValueIfError(t *testing.T) {
+	sm := StringMap{}
+
+	assert.NoError(t, sm.SetString("k1:v1"))
+	assert.Equal(t, map[string]string{"k1": "v1"}, sm.Get())
+
+	assert.Error(t, sm.SetString("k1:v1,k2:v2,k3"))
+	assert.Equal(t, map[string]string{"k1": "v1"}, sm.Get())
+}