From 512b657a42880af87e9f0d863aa6dccf3540d4ba Mon Sep 17 00:00:00 2001
From: Charlie Lukman <lukman.charlie@gmail.com>
Date: Wed, 31 Mar 2021 08:36:51 +0700
Subject: [PATCH] feat: add public matcher function for custom error type
 invalidLengthError (#78)

---
 uuid.go      | 6 ++++++
 uuid_test.go | 7 +++++++
 2 files changed, 13 insertions(+)

diff --git a/uuid.go b/uuid.go
index 60d26bb..d732ae8 100644
--- a/uuid.go
+++ b/uuid.go
@@ -41,6 +41,12 @@ func (err invalidLengthError) Error() string {
 	return fmt.Sprintf("invalid UUID length: %d", err.len)
 }
 
+// IsInvalidLengthError is matcher function for custom error invalidLengthError
+func IsInvalidLengthError(err error) bool {
+	_, ok := err.(invalidLengthError)
+	return ok
+}
+
 // Parse decodes s into a UUID or returns an error.  Both the standard UUID
 // forms of xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx and
 // urn:uuid:xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx are decoded as well as the
diff --git a/uuid_test.go b/uuid_test.go
index 709e34c..99f0bed 100644
--- a/uuid_test.go
+++ b/uuid_test.go
@@ -526,6 +526,13 @@ func TestWrongLength(t *testing.T) {
 	}
 }
 
+func TestIsWrongLength(t *testing.T) {
+	_, err := Parse("12345")
+	if !IsInvalidLengthError(err) {
+		t.Errorf("expected error type is invalidLengthError")
+	}
+}
+
 var asString = "f47ac10b-58cc-0372-8567-0e02b2c3d479"
 var asBytes = []byte(asString)