feat(cc): Add Credit Card ValidatorFuncs to ensure credit cards are v…

…alid

examples/credit-card-form/main.go

@@ -3,6 +3,8 @@ package main
 import (
 	"fmt"
 	"log"
+	"strconv"
+	"strings"
 
 	"github.com/charmbracelet/bubbles/textinput"
 	tea "github.com/charmbracelet/bubbletea"
@@ -42,6 +44,55 @@ type model struct {
 	err     error
 }
 
+// Validator functions to ensure valid input
+func ccnValidator(s string) error {
+	// Credit Card Number should a string less than 20 digits
+	// It should include 16 integers and 3 spaces
+	if len(s) > 16+3 {
+		return fmt.Errorf("CCN is too long")
+	}
+
+	// The last digit should be a number unless it is a multiple of 4 in which
+	// case it should be a space
+	if len(s)%5 == 0 && s[len(s)-1] != ' ' {
+		return fmt.Errorf("CCN must separate groups with spaces")
+	}
+	if len(s)%5 != 0 && (s[len(s)-1] < '0' || s[len(s)-1] > '9') {
+		return fmt.Errorf("CCN is invalid")
+	}
+
+	// The remaining digits should be integers
+	c := strings.ReplaceAll(s, " ", "")
+	_, err := strconv.ParseInt(c, 10, 64)
+
+	return err
+}
+
+func expValidator(s string) error {
+	// The 3 character should be a slash (/)
+	// The rest thould be numbers
+	e := strings.ReplaceAll(s, "/", "")
+	_, err := strconv.ParseInt(e, 10, 64)
+	if err != nil {
+		return fmt.Errorf("EXP is invalid")
+	}
+
+	// There should be only one slash and it should be in the 2nd index (3rd character)
+	if len(s) >= 3 && (strings.Index(s, "/") != 2 || strings.LastIndex(s, "/") != 2) {
+		return fmt.Errorf("EXP is invalid")
+	}
+
+	return nil
+}
+
+func cvvValidator(s string) error {
+	// The CVV should be a number of 3 digits
+	// Since the input will already ensure that the CVV is a string of length 3,
+	// All we need to do is check that it is a number
+	_, err := strconv.ParseInt(s, 10, 64)
+	return err
+}
+
 func initialModel() model {
 	var inputs []textinput.Model = make([]textinput.Model, 3)
 	inputs[ccn] = textinput.New()
@@ -50,18 +101,21 @@ func initialModel() model {
 	inputs[ccn].CharLimit = 20
 	inputs[ccn].Width = 30
 	inputs[ccn].Prompt = ""
+	inputs[ccn].Validate = ccnValidator
 
 	inputs[exp] = textinput.New()
 	inputs[exp].Placeholder = "MM/YY "
 	inputs[exp].CharLimit = 5
 	inputs[exp].Width = 5
 	inputs[exp].Prompt = ""
+	inputs[exp].Validate = expValidator
 
 	inputs[cvv] = textinput.New()
 	inputs[cvv].Placeholder = "XXX"
 	inputs[cvv].CharLimit = 3
 	inputs[cvv].Width = 5
 	inputs[cvv].Prompt = ""
+	inputs[cvv].Validate = cvvValidator
 
 	return model{
 		inputs:  inputs,

examples/go.mod

@@ -3,7 +3,7 @@ module examples
 go 1.13
 
 require (
-	github.com/charmbracelet/bubbles v0.11.0
+	github.com/charmbracelet/bubbles v0.11.1-0.20220610161724-e57fd292cc68
 	github.com/charmbracelet/bubbletea v0.21.0
 	github.com/charmbracelet/glamour v0.5.0
 	github.com/charmbracelet/lipgloss v0.5.0

examples/go.sum

@@ -6,6 +6,8 @@ github.com/aymerick/douceur v0.2.0 h1:Mv+mAeH1Q+n9Fr+oyamOlAkUNPWPlA8PPGR0QAaYuP
 github.com/aymerick/douceur v0.2.0/go.mod h1:wlT5vV2O3h55X9m7iVYN0TBM0NH/MmbLnd30/FjWUq4=
 github.com/charmbracelet/bubbles v0.11.0 h1:fBLyY0PvJnd56Vlu5L84JJH6f4axhgIJ9P3NET78f0Q=
 github.com/charmbracelet/bubbles v0.11.0/go.mod h1:bbeTiXwPww4M031aGi8UK2HT9RDWoiNibae+1yCMtcc=
+github.com/charmbracelet/bubbles v0.11.1-0.20220610161724-e57fd292cc68 h1:oDxdCcM/JreVa7RTt2NQLdp06PwkApSL3huTwrOl/ww=
+github.com/charmbracelet/bubbles v0.11.1-0.20220610161724-e57fd292cc68/go.mod h1:bbeTiXwPww4M031aGi8UK2HT9RDWoiNibae+1yCMtcc=
 github.com/charmbracelet/glamour v0.5.0 h1:wu15ykPdB7X6chxugG/NNfDUbyyrCLV9XBalj5wdu3g=
 github.com/charmbracelet/glamour v0.5.0/go.mod h1:9ZRtG19AUIzcTm7FGLGbq3D5WKQ5UyZBbQsMQN0XIqc=
 github.com/charmbracelet/harmonica v0.2.0 h1:8NxJWRWg/bzKqqEaaeFNipOu77YR5t8aSwG4pgaUBiQ=