feat(map[string]time.Duration): Add support for time.Duration map type

cast.go

@@ -139,6 +139,12 @@ func ToStringMapInt64(i interface{}) map[string]int64 {
 	return v
 }
 
+// ToStringMapTimeDuration casts an interface to a map[string]time.Duration type.
+func ToStringMapTimeDuration(i interface{}) map[string]time.Duration {
+	v, _ := ToStringMapTimeDurationE(i)
+	return v
+}
+
 // ToStringMap casts an interface to a map[string]interface{} type.
 func ToStringMap(i interface{}) map[string]interface{} {
 	v, _ := ToStringMapE(i)

cast_test.go

@@ -946,6 +946,48 @@ func TestToStringMapStringE(t *testing.T) {
 	}
 }
 
+func TestToStringMapTimeDuration(t *testing.T) {
+	var expectResult = map[string]time.Duration{"key 1": 300000000000, "key 2": 36000000000000, "key 3": 4530918273645}
+	var stringMapString = map[string]string{"key 1": "5m", "key 2": "10h", "key 3": "1h15m30.918273645s"}
+	var stringMapInterface = map[string]interface{}{"key 1": "5m", "key 2": "10h", "key 3": "1h15m30.918273645s"}
+	var interfaceMapString = map[interface{}]string{"key 1": "5m", "key 2": "10h", "key 3": "1h15m30.918273645s"}
+	var interfaceMapInterface = map[interface{}]interface{}{"key 1": "5m", "key 2": "10h", "key 3": "1h15m30.918273645s"}
+	var emptyString = ""
+
+	tests := []struct {
+		input  interface{}
+		expect map[string]time.Duration
+		iserr  bool
+	}{
+		{stringMapString, expectResult, false},
+		{stringMapInterface, expectResult, false},
+		{interfaceMapString, expectResult, false},
+		{interfaceMapInterface, expectResult, false},
+
+		// errors
+		{nil, nil, true},
+		{testing.T{}, nil, true},
+		{emptyString, nil, true},
+	}
+
+	for i, test := range tests {
+		errmsg := fmt.Sprintf("i = %d", i) // assert helper message
+
+		v, err := ToStringMapTimeDurationE(test.input)
+		if test.iserr {
+			assert.Error(t, err, errmsg)
+			continue
+		}
+
+		assert.NoError(t, err, errmsg)
+		assert.Equal(t, test.expect, v, errmsg)
+
+		// Non-E test
+		v = ToStringMapTimeDuration(test.input)
+		assert.Equal(t, test.expect, v, errmsg)
+	}
+}
+
 func TestToBoolSliceE(t *testing.T) {
 	tests := []struct {
 		input  interface{}

caste.go

@@ -1078,6 +1078,36 @@ func ToStringMapInt64E(i interface{}) (map[string]int64, error) {
 	return m, nil
 }
 
+// ToStringMapTimeDurationE casts an interface to a map[string]time.Duration type.
+func ToStringMapTimeDurationE(i interface{}) (map[string]time.Duration, error) {
+	var m = map[string]time.Duration{}
+
+	switch v := i.(type) {
+	case map[string]string:
+		for k, val := range v {
+			m[ToString(k)] = ToDuration(val)
+		}
+		return m, nil
+	case map[string]interface{}:
+		for k, val := range v {
+			m[ToString(k)] = ToDuration(val)
+		}
+		return m, nil
+	case map[interface{}]string:
+		for k, val := range v {
+			m[ToString(k)] = ToDuration(val)
+		}
+		return m, nil
+	case map[interface{}]interface{}:
+		for k, val := range v {
+			m[ToString(k)] = ToDuration(val)
+		}
+		return m, nil
+	default:
+		return m, fmt.Errorf("unable to cast %#v of type %T to map[string]time.Duration", i, i)
+	}
+}
+
 // ToSliceE casts an interface to a []interface{} type.
 func ToSliceE(i interface{}) ([]interface{}, error) {
 	var s []interface{}