refactored for maintainability

internal/validation/integerfield.go

@@ -0,0 +1,71 @@
+package validation
+
+import (
+	"fmt"
+	"strconv"
+)
+
+type IntField struct {
+	Field
+	Value int
+}
+
+func newIntField(key string, g Getter) *IntField {
+	raw := g.Get(key)
+	var val int
+	if raw != "" {
+		var err error
+		val, err = strconv.Atoi(raw)
+		if err != nil {
+			g.AddCheck(newFailedCheck(
+				"Value is not a number",
+				fmt.Sprintf("%s must be an integer: %s provided", key, raw),
+			))
+		}
+	}
+	return &IntField{
+		Value: val,
+		Field: newField(key, g),
+	}
+}
+
+// Required enforces a non-zero value
+func (i *IntField) Required() *IntField {
+	if i.Value == 0 {
+		i.getter.AddCheck(newFailedCheck(
+			"Value cannot be 0",
+			fmt.Sprintf("%s is required", i.Key),
+		))
+	}
+	return i
+}
+
+// Optional will skip all validations if value is empty
+func (i *IntField) Optional() *IntField {
+	if i.Value == 0 {
+		i.optional = true
+	}
+	return i
+}
+
+// Max enforces a maxmium value
+func (i *IntField) Max(max int) *IntField {
+	if i.Value > max && !i.optional {
+		i.getter.AddCheck(newFailedCheck(
+			"Value too large",
+			fmt.Sprintf("%s is too large, max %v", i.Key, max),
+		))
+	}
+	return i
+}
+
+// Min enforces a minimum value
+func (i *IntField) Min(min int) *IntField {
+	if i.Value < min && !i.optional {
+		i.getter.AddCheck(newFailedCheck(
+			"Value too small",
+			fmt.Sprintf("%s is too small, min %v", i.Key, min),
+		))
+	}
+	return i
+}