move error types and constants out to separate file

errors.go

@@ -0,0 +1,43 @@
+package jwt
+
+import (
+	"errors"
+)
+
+// Error constants
+var (
+	ErrInvalidKey       = errors.New("key is invalid or of invalid type")
+	ErrHashUnavailable  = errors.New("the requested hash function is unavailable")
+	ErrNoTokenInRequest = errors.New("no token present in request")
+)
+
+// The errors that might occur when parsing and validating a token
+const (
+	ValidationErrorMalformed        uint32 = 1 << iota // Token is malformed
+	ValidationErrorUnverifiable                        // Token could not be verified because of signing problems
+	ValidationErrorSignatureInvalid                    // Signature validation failed
+	ValidationErrorExpired                             // Exp validation failed
+	ValidationErrorNotValidYet                         // NBF validation failed
+)
+
+// The error from Parse if token is not valid
+type ValidationError struct {
+	err    string
+	Errors uint32 // bitfield.  see ValidationError... constants
+}
+
+// Validation error is an error type
+func (e ValidationError) Error() string {
+	if e.err == "" {
+		return "token is invalid"
+	}
+	return e.err
+}
+
+// No errors
+func (e *ValidationError) valid() bool {
+	if e.Errors > 0 {
+		return false
+	}
+	return true
+}

jwt.go

@@ -3,7 +3,6 @@ package jwt
 import (
 	"encoding/base64"
 	"encoding/json"
-	"errors"
 	"net/http"
 	"strings"
 	"time"
@@ -20,13 +19,6 @@ var TimeFunc = time.Now
 // Header of the token (such as `kid`) to identify which key to use.
 type Keyfunc func(*Token) (interface{}, error)
 
-// Error constants
-var (
-	ErrInvalidKey       = errors.New("key is invalid or of invalid type")
-	ErrHashUnavailable  = errors.New("the requested hash function is unavailable")
-	ErrNoTokenInRequest = errors.New("no token present in request")
-)
-
 // A JWT Token.  Different fields will be used depending on whether you're
 // creating or parsing/verifying a token.
 type Token struct {
@@ -167,37 +159,6 @@ func Parse(tokenString string, keyFunc Keyfunc) (*Token, error) {
 	return token, vErr
 }
 
-// The errors that might occur when parsing and validating a token
-const (
-	ValidationErrorMalformed        uint32 = 1 << iota // Token is malformed
-	ValidationErrorUnverifiable                        // Token could not be verified because of signing problems
-	ValidationErrorSignatureInvalid                    // Signature validation failed
-	ValidationErrorExpired                             // Exp validation failed
-	ValidationErrorNotValidYet                         // NBF validation failed
-)
-
-// The error from Parse if token is not valid
-type ValidationError struct {
-	err    string
-	Errors uint32 // bitfield.  see ValidationError... constants
-}
-
-// Validation error is an error type
-func (e ValidationError) Error() string {
-	if e.err == "" {
-		return "token is invalid"
-	}
-	return e.err
-}
-
-// No errors
-func (e *ValidationError) valid() bool {
-	if e.Errors > 0 {
-		return false
-	}
-	return true
-}
-
 // Try to find the token in an http.Request.
 // This method will call ParseMultipartForm if there's no token in the header.
 // Currently, it looks in the Authorization header as well as