added tests for HashPIN and VerifyPIN

common/pin_test.go

@@ -1,6 +1,10 @@
 package common
 
-import "testing"
+import (
+	"testing"
+
+	"golang.org/x/crypto/bcrypt"
+)
 
 func TestIsValidPIN(t *testing.T) {
 	tests := []struct {
@@ -54,3 +58,95 @@ func TestIsValidPIN(t *testing.T) {
 		})
 	}
 }
+
+func TestHashPIN(t *testing.T) {
+	tests := []struct {
+		name string
+		pin  string
+	}{
+		{
+			name: "Valid PIN with 4 digits",
+			pin:  "1234",
+		},
+		{
+			name: "Valid PIN with leading zeros",
+			pin:  "0001",
+		},
+		{
+			name: "Empty PIN",
+			pin:  "",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			hashedPIN, err := HashPIN(tt.pin)
+			if err != nil {
+				t.Errorf("HashPIN(%q) returned an error: %v", tt.pin, err)
+				return
+			}
+
+			if hashedPIN == "" {
+				t.Errorf("HashPIN(%q) returned an empty hash", tt.pin)
+			}
+
+			// Ensure the hash can be verified with bcrypt
+			err = bcrypt.CompareHashAndPassword([]byte(hashedPIN), []byte(tt.pin))
+			if tt.pin != "" && err != nil {
+				t.Errorf("HashPIN(%q) produced a hash that does not match: %v", tt.pin, err)
+			}
+		})
+	}
+}
+
+func TestVerifyPIN(t *testing.T) {
+	tests := []struct {
+		name       string
+		pin        string
+		hashedPIN  string
+		shouldPass bool
+	}{
+		{
+			name:       "Valid PIN verification",
+			pin:        "1234",
+			hashedPIN:  hashPINHelper("1234"),
+			shouldPass: true,
+		},
+		{
+			name:       "Invalid PIN verification with incorrect PIN",
+			pin:        "5678",
+			hashedPIN:  hashPINHelper("1234"),
+			shouldPass: false,
+		},
+		{
+			name:       "Invalid PIN verification with empty PIN",
+			pin:        "",
+			hashedPIN:  hashPINHelper("1234"),
+			shouldPass: false,
+		},
+		{
+			name:       "Invalid PIN verification with invalid hash",
+			pin:        "1234",
+			hashedPIN:  "invalidhash",
+			shouldPass: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := VerifyPIN(tt.hashedPIN, tt.pin)
+			if result != tt.shouldPass {
+				t.Errorf("VerifyPIN(%q, %q) = %v; expected %v", tt.hashedPIN, tt.pin, result, tt.shouldPass)
+			}
+		})
+	}
+}
+
+// Helper function to hash a PIN for testing purposes
+func hashPINHelper(pin string) string {
+	hashedPIN, err := HashPIN(pin)
+	if err != nil {
+		panic("Failed to hash PIN for test setup: " + err.Error())
+	}
+	return hashedPIN
+}