updated README.md file

README.md

@@ -1,11 +1,14 @@
 # go-errhttp
 
-Package **errhttp** provides types errors that make dealing with HTTP response errors easier, for the Go programming language.
+Package **errhttp** provides errors and types that make dealing with HTTP response errors easier, for the Go programming language.
 
 
 ## Example
+
+Here is an example of wrapping an error:
+
 ```go
-	import "github.com/reiver/go-errhttp"
+	import "sourcecode.social/reiver/go-errhttp"
 	
 	// ...
 	
@@ -33,8 +36,37 @@ Package **errhttp** provides types errors that make dealing with HTTP response e
 	}
 ```
 
+Here is an example of using one of the package global variable errors:
+
+```go
+	import "sourcecode.social/reiver/go-errhttp"
+	
+	// ...
+	
+	return errhttp.ErrBadRequest
+	
+	// ...
+	
+	switch err.(type) {
+	case errhttp.BadRequest:
+		//@TODO
+	case errhttp.NotFound:
+		//@TODO
+	case errhttp.InternalServerError:
+		//@TODO
+	
+	case errhttp.ClientError:
+		//@TODO
+	case errhttp.ServerError:
+		//@TODO
+	
+	default:
+		//@TODO
+	}
+```
+
 ## Documention
 
-Online documentation, which includes examples, can be found at: http://godoc.org/github.com/reiver/go-errhttp
+Online documentation, which includes examples, can be found at: http://godoc.org/sourcecode.social/reiver/go-errhttp
 
-[![GoDoc](https://godoc.org/github.com/reiver/go-errhttp?status.svg)](https://godoc.org/github.com/reiver/go-errhttp)
+[![GoDoc](https://godoc.org/sourcecode.social/reiver/go-errhttp?status.svg)](https://godoc.org/sourcecode.social/reiver/go-errhttp)

badgateway.go

@@ -1,10 +1,18 @@
 package errhttp
 
+var _ Error       = internalBadGateway{}
+var _ ServerError = internalBadGateway{}
+var _ BadGateway  = internalBadGateway{}
+
+var ErrBadGateway error = BadGatewayWrap(nil)
+
 type BadGateway interface {
 	ServerError
 	BadGateway()
 }
 
+var _ BadGateway = internalBadGateway{}
+
 type internalBadGateway struct {
 	err error
 }
@@ -19,8 +27,8 @@ func (receiver internalBadGateway) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalBadGateway) Err() error {
+func (internalBadGateway) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalBadGateway) ServerError() {
@@ -30,3 +38,7 @@ func (internalBadGateway) ServerError() {
 func (internalBadGateway) BadGateway() {
 	// Nothing here.
 }
+
+func (receiver internalBadGateway) Unwrap() error {
+	return receiver.err
+}

badrequest.go

@@ -1,5 +1,11 @@
 package errhttp
 
+var _ Error       = internalBadRequest{}
+var _ ClientError = internalBadRequest{}
+var _ BadRequest  = internalBadRequest{}
+
+var ErrBadRequest = BadRequestWrap(nil)
+
 type BadRequest interface {
 	ClientError
 	BadRequest()
@@ -19,8 +25,8 @@ func (receiver internalBadRequest) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalBadRequest) Err() error {
+func (internalBadRequest) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalBadRequest) ClientError() {
@@ -30,3 +36,7 @@ func (internalBadRequest) ClientError() {
 func (internalBadRequest) BadRequest() {
 	// Nothing here.
 }
+
+func (receiver internalBadRequest) Unwrap() error {
+	return receiver.err
+}

badrequest_test.go

@@ -1,14 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestBadRequest(t *testing.T) {
-
-	var x BadRequest = internalBadRequest{} // THIS IS THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should not happen.")
-	}
-}

clienterror_test.go

@@ -1,42 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestClientError(t *testing.T) {
-
-	var x ClientError
-
-	x = internalBadRequest{}                   // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalUnauthorized{}                 // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalPaymentRequired{}              // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalForbidden{}                    // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalNotFound{}                     // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalMethodNotAllowed{}             // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalNotAcceptable{}                // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalProxyAuthRequired{}            // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalRequestTimeout{}               // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalConflict{}                     // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalGone{}                         // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalLengthRequired{}               // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalPreconditionFailed{}           // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalRequestEntityTooLarge{}        // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalRequestURITooLong{}            // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalUnsupportedMediaType{}         // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalRequestedRangeNotSatisfiable{} // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalExpectationFailed{}            // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalTeapot{}                       // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalUnprocessableEntity{}          // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalLocked{}                       // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalFailedDependency{}             // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalUpgradeRequired{}              // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalPreconditionRequired{}         // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalTooManyRequests{}              // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalRequestHeaderFieldsTooLarge{}  // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalUnavailableForLegalReasons{}   // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should never happen.")
-	}
-}

conflict.go

@@ -1,5 +1,11 @@
 package errhttp
 
+var _ Error       = internalConflict{}
+var _ ClientError = internalConflict{}
+var _ Conflict    = internalConflict{}
+
+var ErrConflict = ConflictWrap(nil)
+
 type Conflict interface {
 	ClientError
 	Conflict()
@@ -19,8 +25,8 @@ func (receiver internalConflict) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalConflict) Err() error {
+func (internalConflict) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalConflict) ClientError() {
@@ -30,3 +36,7 @@ func (internalConflict) ClientError() {
 func (internalConflict) Conflict() {
 	// Nothing here.
 }
+
+func (receiver internalConflict) Unwrap() error {
+	return receiver.err
+}

conflict_test.go

@@ -1,14 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestConflict(t *testing.T) {
-
-	var x Conflict = internalConflict{} // THIS IS THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should not happen.")
-	}
-}

doc.go

@@ -1,33 +0,0 @@
-/*
-Package errhttp provides types errors that make dealing with HTTP response errors easier.
-
-Example
-
-	import "github.com/reiver/go-errhttp"
-	
-	// ...
-	
-	if err := something(); nil != err {
-		return errhttp.BadRequestWrap(err)
-	}
-	
-	// ...
-	
-	switch err.(type) {
-	case errhttp.BadRequest:
-		//@TODO
-	case errhttp.NotFound:
-		//@TODO
-	case errhttp.InternalServerError:
-		//@TODO
-	
-	case errhttp.ClientError:
-		//@TODO
-	case errhttp.ServerError:
-		//@TODO
-	
-	default:
-		//@TODO
-	}
-*/
-package errhttp

error.go

@@ -2,5 +2,6 @@ package errhttp
 
 type Error interface {
 	error
-	Err() error
+	ErrHTTP()
+	Unwrap() error
 }

expectationfailed.go

@@ -1,5 +1,11 @@
 package errhttp
 
+var _ Error             = internalExpectationFailed{}
+var _ ClientError       = internalExpectationFailed{}
+var _ ExpectationFailed = internalExpectationFailed{}
+
+var ErrExpectationFailed error = ExpectationFailedWrap(nil)
+
 type ExpectationFailed interface {
 	ClientError
 	ExpectationFailed()
@@ -19,8 +25,8 @@ func (receiver internalExpectationFailed) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalExpectationFailed) Err() error {
+func (internalExpectationFailed) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalExpectationFailed) ClientError() {
@@ -30,3 +36,7 @@ func (internalExpectationFailed) ClientError() {
 func (internalExpectationFailed) ExpectationFailed() {
 	// Nothing here.
 }
+
+func (receiver internalExpectationFailed) Unwrap() error {
+	return receiver.err
+}

expectationfailed_test.go

@@ -1,14 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestExpectationFailed(t *testing.T) {
-
-	var x ExpectationFailed = internalExpectationFailed{} // THIS IS THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should not happen.")
-	}
-}

faileddependency.go

@@ -1,5 +1,11 @@
 package errhttp
 
+var _ Error            = internalFailedDependency{}
+var _ ClientError      = internalFailedDependency{}
+var _ FailedDependency = internalFailedDependency{}
+
+var ErrFailedDependency error = FailedDependencyWrap(nil)
+
 type FailedDependency interface {
 	ClientError
 	FailedDependency()
@@ -19,8 +25,8 @@ func (receiver internalFailedDependency) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalFailedDependency) Err() error {
+func (internalFailedDependency) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalFailedDependency) ClientError() {
@@ -31,3 +37,6 @@ func (internalFailedDependency) FailedDependency() {
 	// Nothing here.
 }
 
+func (receiver internalFailedDependency) Unwrap() error {
+	return receiver.err
+}

faileddependency_test.go

@@ -1,14 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestFailedDependency(t *testing.T) {
-
-	var x FailedDependency = internalFailedDependency{} // THIS IS THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should not happen.")
-	}
-}

forbidden.go

@@ -1,5 +1,11 @@
 package errhttp
 
+var _ Error       = internalForbidden{}
+var _ ClientError = internalForbidden{}
+var _ Forbidden   = internalForbidden{}
+
+var ErrForbidden error = ForbiddenWrap(nil)
+
 type Forbidden interface {
 	ClientError
 	Forbidden()
@@ -19,8 +25,8 @@ func (receiver internalForbidden) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalForbidden) Err() error {
+func (internalForbidden) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalForbidden) ClientError() {
@@ -31,3 +37,6 @@ func (internalForbidden) Forbidden() {
 	// Nothing here.
 }
 
+func (receiver internalForbidden) Unwrap() error {
+	return receiver.err
+}

forbidden_test.go

@@ -1,14 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestForbidden(t *testing.T) {
-
-	var x Forbidden = internalForbidden{} // THIS IS THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should not happen.")
-	}
-}

gatewaytimeout.go

@@ -1,10 +1,18 @@
 package errhttp
 
+var _ Error          = internalGatewayTimeout{}
+var _ ServerError    = internalGatewayTimeout{}
+var _ GatewayTimeout = internalGatewayTimeout{}
+
+var ErrGatewayTimeout error = GatewayTimeoutWrap(nil)
+
 type GatewayTimeout interface {
 	ServerError
 	GatewayTimeout()
 }
 
+var _ GatewayTimeout = internalGatewayTimeout{}
+
 type internalGatewayTimeout struct {
 	err error
 }
@@ -19,8 +27,8 @@ func (receiver internalGatewayTimeout) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalGatewayTimeout) Err() error {
+func (internalGatewayTimeout) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalGatewayTimeout) ServerError() {
@@ -30,3 +38,7 @@ func (internalGatewayTimeout) ServerError() {
 func (internalGatewayTimeout) GatewayTimeout() {
 	// Nothing here.
 }
+
+func (receiver internalGatewayTimeout) Unwrap() error {
+	return receiver.err
+}

gone.go

@@ -1,5 +1,11 @@
 package errhttp
 
+var _ Error       = internalGone{}
+var _ ClientError = internalGone{}
+var _ Gone        = internalGone{}
+
+var ErrGone error = GoneWrap(nil)
+
 type Gone interface {
 	ClientError()
 	Gone()
@@ -19,8 +25,8 @@ func (receiver internalGone) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalGone) Err() error {
+func (internalGone) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalGone) ClientError() {
@@ -31,3 +37,6 @@ func (internalGone) Gone() {
 	// Nothing here.
 }
 
+func (receiver internalGone) Unwrap() error {
+	return receiver.err
+}

gone_test.go

@@ -1,14 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestGone(t *testing.T) {
-
-	var x Gone = internalGone{} // THIS IS THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should not happen.")
-	}
-}

httpversionnotsupported.go

@@ -1,10 +1,18 @@
 package errhttp
 
+var _ Error                   = internalHTTPVersionNotSupported{}
+var _ ServerError             = internalHTTPVersionNotSupported{}
+var _ HTTPVersionNotSupported = internalHTTPVersionNotSupported{}
+
+var ErrHTTPVersionNotSupported error = HTTPVersionNotSupportedWrap(nil)
+
 type HTTPVersionNotSupported interface {
 	ServerError
 	HTTPVersionNotSupported()
 }
 
+var _ HTTPVersionNotSupported = internalHTTPVersionNotSupported{}
+
 type internalHTTPVersionNotSupported struct {
 	err error
 }
@@ -19,8 +27,8 @@ func (receiver internalHTTPVersionNotSupported) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalHTTPVersionNotSupported) Err() error {
+func (internalHTTPVersionNotSupported) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalHTTPVersionNotSupported) ServerError() {
@@ -30,3 +38,7 @@ func (internalHTTPVersionNotSupported) ServerError() {
 func (internalHTTPVersionNotSupported) HTTPVersionNotSupported() {
 	// Nothing here.
 }
+
+func (receiver internalHTTPVersionNotSupported) Unwrap() error {
+	return receiver.err
+}

insufficientstorage.go

@@ -1,10 +1,18 @@
 package errhttp
 
+var _ Error               = internalInsufficientStorage{}
+var _ ServerError         = internalInsufficientStorage{}
+var _ InsufficientStorage = internalInsufficientStorage{}
+
+var ErrInsufficientStorage error = InsufficientStorageWrap(nil)
+
 type InsufficientStorage interface {
 	ServerError
 	InsufficientStorage()
 }
 
+var _ InsufficientStorage = internalInsufficientStorage{}
+
 type internalInsufficientStorage struct {
 	err error
 }
@@ -19,8 +27,8 @@ func (receiver internalInsufficientStorage) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalInsufficientStorage) Err() error {
+func (internalInsufficientStorage) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalInsufficientStorage) ServerError() {
@@ -30,3 +38,7 @@ func (internalInsufficientStorage) ServerError() {
 func (internalInsufficientStorage) InsufficientStorage() {
 	// Nothing here.
 }
+
+func (receiver internalInsufficientStorage) Unwrap() error {
+	return receiver.err
+}

internalservererror.go

@@ -1,10 +1,18 @@
 package errhttp
 
+var _ Error               = internalInternalServerError{}
+var _ ServerError         = internalInternalServerError{}
+var _ InternalServerError = internalInternalServerError{}
+
+var ErrInternalServerError error = InternalServerErrorWrap(nil)
+
 type InternalServerError interface {
 	ServerError
 	InternalServerError()
 }
 
+var _ InternalServerError = internalInternalServerError{}
+
 type internalInternalServerError struct {
 	err error
 }
@@ -19,8 +27,8 @@ func (receiver internalInternalServerError) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalInternalServerError) Err() error {
+func (internalInternalServerError) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalInternalServerError) ServerError() {
@@ -30,3 +38,7 @@ func (internalInternalServerError) ServerError() {
 func (internalInternalServerError) InternalServerError() {
 	// Nothing here.
 }
+
+func (receiver internalInternalServerError) Unwrap() error {
+	return receiver.err
+}

lengthrequired.go

@@ -1,5 +1,11 @@
 package errhttp
 
+var _ Error          = internalLengthRequired{}
+var _ ClientError    = internalLengthRequired{}
+var _ LengthRequired = internalLengthRequired{}
+
+var ErrLengthRequired error = LengthRequiredWrap(nil)
+
 type LengthRequired interface {
 	ClientError
 	LengthRequired()
@@ -19,8 +25,8 @@ func (receiver internalLengthRequired) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalLengthRequired) Err() error {
+func (internalLengthRequired) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalLengthRequired) ClientError() {
@@ -31,3 +37,6 @@ func (internalLengthRequired) LengthRequired() {
 	// Nothing here.
 }
 
+func (receiver internalLengthRequired) Unwrap() error {
+	return receiver.err
+}

lengthrequired_test.go

@@ -1,14 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestLengthRequired(t *testing.T) {
-
-	var x LengthRequired = internalLengthRequired{} // THIS IS THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should not happen.")
-	}
-}

locked.go

@@ -1,5 +1,11 @@
 package errhttp
 
+var _ Error        = internalLocked{}
+var _ ClientError  = internalLocked{}
+var _ Locked       = internalLocked{}
+
+var ErrLocked error = LockedWrap(nil)
+
 type Locked interface {
 	ClientError
 	Locked()
@@ -19,8 +25,8 @@ func (receiver internalLocked) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalLocked) Err() error {
+func (internalLocked) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalLocked) ClientError() {
@@ -30,3 +36,7 @@ func (internalLocked) ClientError() {
 func (internalLocked) Locked() {
 	// Nothing here.
 }
+
+func (receiver internalLocked) Unwrap() error {
+	return receiver.err
+}

locked_test.go

@@ -1,14 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestLocked(t *testing.T) {
-
-	var x Locked = internalLocked{} // THIS IS THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should not happen.")
-	}
-}

loopdetected.go

@@ -1,10 +1,18 @@
 package errhttp
 
+var _ Error        = internalLoopDetected{}
+var _ ServerError  = internalLoopDetected{}
+var _ LoopDetected = internalLoopDetected{}
+
+var ErrLoopDetected error = LoopDetectedWrap(nil)
+
 type LoopDetected interface {
 	ServerError
 	LoopDetected()
 }
 
+var _ LoopDetected = internalLoopDetected{}
+
 type internalLoopDetected struct {
 	err error
 }
@@ -19,8 +27,8 @@ func (receiver internalLoopDetected) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalLoopDetected) Err() error {
+func (internalLoopDetected) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalLoopDetected) ServerError() {
@@ -30,3 +38,7 @@ func (internalLoopDetected) ServerError() {
 func (internalLoopDetected) LoopDetected() {
 	// Nothing here.
 }
+
+func (receiver internalLoopDetected) Unwrap() error {
+	return receiver.err
+}

methodnotallowed.go

@@ -1,5 +1,11 @@
 package errhttp
 
+var _ Error            = internalMethodNotAllowed{}
+var _ ClientError      = internalMethodNotAllowed{}
+var _ MethodNotAllowed = internalMethodNotAllowed{}
+
+var ErrMethodNotAllowed error = MethodNotAllowedWrap(nil)
+
 type MethodNotAllowed interface {
 	ClientError
 	MethodNotAllowed()
@@ -19,8 +25,8 @@ func (receiver internalMethodNotAllowed) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalMethodNotAllowed) Err() error {
+func (internalMethodNotAllowed) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalMethodNotAllowed) ClientError() {
@@ -31,3 +37,6 @@ func (internalMethodNotAllowed) MethodNotAllowed() {
 	// Nothing here.
 }
 
+func (receiver internalMethodNotAllowed) Unwrap() error {
+	return receiver.err
+}

methodnotallowed_test.go

@@ -1,14 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestMethodNotAllowed(t *testing.T) {
-
-	var x MethodNotAllowed = internalMethodNotAllowed{} // THIS IS THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should not happen.")
-	}
-}

networkauthenticationrequired.go

@@ -1,10 +1,18 @@
 package errhttp
 
+var _ Error                         = internalNetworkAuthenticationRequired{}
+var _ ServerError                   = internalNetworkAuthenticationRequired{}
+var _ NetworkAuthenticationRequired = internalNetworkAuthenticationRequired{}
+
+var ErrNetworkAuthenticationRequired error = NetworkAuthenticationRequiredWrap(nil)
+
 type NetworkAuthenticationRequired interface {
 	ServerError
 	NetworkAuthenticationRequired()
 }
 
+var _ NetworkAuthenticationRequired = internalNetworkAuthenticationRequired{}
+
 type internalNetworkAuthenticationRequired struct {
 	err error
 }
@@ -19,8 +27,8 @@ func (receiver internalNetworkAuthenticationRequired) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalNetworkAuthenticationRequired) Err() error {
+func (internalNetworkAuthenticationRequired) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalNetworkAuthenticationRequired) ServerError() {
@@ -30,3 +38,7 @@ func (internalNetworkAuthenticationRequired) ServerError() {
 func (internalNetworkAuthenticationRequired) NetworkAuthenticationRequired() {
 	// Nothing here.
 }
+
+func (receiver internalNetworkAuthenticationRequired) Unwrap() error {
+	return receiver.err
+}

notacceptable.go

@@ -1,5 +1,11 @@
 package errhttp
 
+var _ Error         = internalNotAcceptable{}
+var _ ClientError   = internalNotAcceptable{}
+var _ NotAcceptable = internalNotAcceptable{}
+
+var ErrNotAcceptable error = NotAcceptableWrap(nil)
+
 type NotAcceptable interface {
 	ClientError
 	NotAcceptable()
@@ -19,8 +25,8 @@ func (receiver internalNotAcceptable) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalNotAcceptable) Err() error {
+func (internalNotAcceptable) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalNotAcceptable) ClientError() {
@@ -30,3 +36,7 @@ func (internalNotAcceptable) ClientError() {
 func (internalNotAcceptable) NotAcceptable() {
 	// Nothing here.
 }
+
+func (receiver internalNotAcceptable) Unwrap() error {
+	return receiver.err
+}

notacceptable_test.go

@@ -1,14 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestNotAcceptable(t *testing.T) {
-
-	var x NotAcceptable = internalNotAcceptable{} // THIS IS THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should not happen.")
-	}
-}

notextended.go

@@ -1,10 +1,18 @@
 package errhttp
 
+var _ Error       = internalNotExtended{}
+var _ ServerError = internalNotExtended{}
+var _ NotExtended = internalNotExtended{}
+
+var ErrNotExtended error = NotExtendedWrap(nil)
+
 type NotExtended interface {
 	ServerError
 	NotExtended()
 }
 
+var _ NotExtended = internalNotExtended{}
+
 type internalNotExtended struct {
 	err error
 }
@@ -19,8 +27,8 @@ func (receiver internalNotExtended) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalNotExtended) Err() error {
+func (internalNotExtended) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalNotExtended) ServerError() {
@@ -30,3 +38,7 @@ func (internalNotExtended) ServerError() {
 func (internalNotExtended) NotExtended() {
 	// Nothing here.
 }
+
+func (receiver internalNotExtended) Unwrap() error {
+	return receiver.err
+}

notfound.go

@@ -1,11 +1,17 @@
 package errhttp
 
+var _ Error       = internalNotFound{}
+var _ ClientError = internalNotFound{}
+var _ NotFound    = internalNotFound{}
+
+var ErrNotFound error = NotFoundWrap(nil)
+
 type NotFound  interface {
 	ClientError
 	NotFound ()
 }
 
-type internalNotFound  struct {
+type internalNotFound struct {
 	err error
 }
 
@@ -19,8 +25,8 @@ func (receiver internalNotFound ) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalNotFound ) Err() error {
+func (internalNotFound ) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalNotFound ) ClientError() {
@@ -30,3 +36,7 @@ func (internalNotFound ) ClientError() {
 func (internalNotFound ) NotFound() {
 	// Nothing here.
 }
+
+func (receiver internalNotFound) Unwrap() error {
+	return receiver.err
+}

notfound_test.go

@@ -1,14 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestNotFound(t *testing.T) {
-
-	var x NotFound = internalNotFound{} // THIS IS THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should not happen.")
-	}
-}

notimplemented.go

@@ -1,10 +1,18 @@
 package errhttp
 
+var _ Error          = internalNotImplemented{}
+var _ ServerError    = internalNotImplemented{}
+var _ NotImplemented = internalNotImplemented{}
+
+var ErrNotImplemented error = NotImplementedWrap(nil)
+
 type NotImplemented interface {
 	ServerError
 	NotImplemented()
 }
 
+var _ NotImplemented = internalNotImplemented{}
+
 type internalNotImplemented struct {
 	err error
 }
@@ -19,8 +27,8 @@ func (receiver internalNotImplemented) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalNotImplemented) Err() error {
+func (internalNotImplemented) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalNotImplemented) ServerError() {
@@ -30,3 +38,7 @@ func (internalNotImplemented) ServerError() {
 func (internalNotImplemented) NotImplemented() {
 	// Nothing here.
 }
+
+func (receiver internalNotImplemented) Unwrap() error {
+	return receiver.err
+}

payloadtoolarge.go

@@ -0,0 +1,42 @@
+package errhttp
+
+var _ Error           = internalPayloadTooLarge{}
+var _ ClientError     = internalPayloadTooLarge{}
+var _ PayloadTooLarge = internalPayloadTooLarge{}
+
+var ErrPayloadTooLarge error = PayloadTooLargeWrap(nil)
+
+type PayloadTooLarge interface {
+	ClientError
+	PayloadTooLarge()
+}
+
+type internalPayloadTooLarge struct {
+	err error
+}
+
+func PayloadTooLargeWrap(err error) error {
+	return internalPayloadTooLarge{
+		err:err,
+	}
+}
+
+func (receiver internalPayloadTooLarge) Error() string {
+	return receiver.err.Error()
+}
+
+func (internalPayloadTooLarge) ErrHTTP() {
+	// Nothing here.
+}
+
+func (internalPayloadTooLarge) ClientError() {
+	// Nothing here.
+}
+
+func (internalPayloadTooLarge) PayloadTooLarge() {
+	// Nothing here.
+}
+
+func (receiver internalPayloadTooLarge) Unwrap() error {
+	return receiver.err
+}

paymentrequired.go

@@ -1,5 +1,11 @@
 package errhttp
 
+var _ Error           = internalPaymentRequired{}
+var _ ClientError     = internalPaymentRequired{}
+var _ PaymentRequired = internalPaymentRequired{}
+
+var ErrPaymentRequired error = PaymentRequiredWrap(nil)
+
 type PaymentRequired interface {
 	ClientError
 	PaymentRequired()
@@ -19,10 +25,11 @@ func (receiver internalPaymentRequired) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalPaymentRequired) Err() error {
+func (internalPaymentRequired) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
+
 func (internalPaymentRequired) ClientError() {
 	// Nothing here.
 }
@@ -30,3 +37,7 @@ func (internalPaymentRequired) ClientError() {
 func (internalPaymentRequired) PaymentRequired() {
 	// Nothing here.
 }
+
+func (receiver internalPaymentRequired) Unwrap() error {
+	return receiver.err
+}

paymentrequired_test.go

@@ -1,14 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestPaymentRequired(t *testing.T) {
-
-	var x PaymentRequired = internalPaymentRequired{} // THIS IS THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should not happen.")
-	}
-}

preconditionfailed.go

@@ -1,5 +1,11 @@
 package errhttp
 
+var _ Error              = internalPreconditionFailed{}
+var _ ClientError        = internalPreconditionFailed{}
+var _ PreconditionFailed = internalPreconditionFailed{}
+
+var ErrPreconditionFailed error = PreconditionFailedWrap(nil)
+
 type PreconditionFailed interface {
 	ClientError
 	PreconditionFailed()
@@ -19,8 +25,8 @@ func (receiver internalPreconditionFailed) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalPreconditionFailed) Err() error {
+func (internalPreconditionFailed) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalPreconditionFailed) ClientError() {
@@ -30,3 +36,7 @@ func (internalPreconditionFailed) ClientError() {
 func (internalPreconditionFailed) PreconditionFailed() {
 	// Nothing here.
 }
+
+func (receiver internalPreconditionFailed) Unwrap() error {
+	return receiver.err
+}

preconditionfailed_test.go

@@ -1,14 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestPreconditionFailed(t *testing.T) {
-
-	var x PreconditionFailed = internalPreconditionFailed{} // THIS IS THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should not happen.")
-	}
-}

preconditionrequired.go

@@ -1,5 +1,11 @@
 package errhttp
 
+var _ Error                = internalPreconditionRequired{}
+var _ ClientError          = internalPreconditionRequired{}
+var _ PreconditionRequired = internalPreconditionRequired{}
+
+var ErrPreconditionRequired error = PreconditionRequiredWrap(nil)
+
 type PreconditionRequired interface {
 	ClientError
 	PreconditionRequired()
@@ -19,8 +25,8 @@ func (receiver internalPreconditionRequired) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalPreconditionRequired) Err() error {
+func (internalPreconditionRequired) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalPreconditionRequired) ClientError() {
@@ -31,3 +37,6 @@ func (internalPreconditionRequired) PreconditionRequired() {
 	// Nothing here.
 }
 
+func (receiver internalPreconditionRequired) Unwrap() error {
+	return receiver.err
+}

preconditionrequired_test.go

@@ -1,14 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestPreconditionRequired(t *testing.T) {
-
-	var x PreconditionRequired = internalPreconditionRequired{} // THIS IS THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should not happen.")
-	}
-}

proxyauthrequired.go

@@ -1,5 +1,11 @@
 package errhttp
 
+var _ Error             = internalProxyAuthRequired{}
+var _ ClientError       = internalProxyAuthRequired{}
+var _ ProxyAuthRequired = internalProxyAuthRequired{}
+
+var ErrProxyAuthRequired error = ProxyAuthRequiredWrap(nil)
+
 type ProxyAuthRequired interface {
 	ClientError
 	ProxyAuthRequired()
@@ -19,8 +25,8 @@ func (receiver internalProxyAuthRequired) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalProxyAuthRequired) Err() error {
+func (internalProxyAuthRequired) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalProxyAuthRequired) ClientError() {
@@ -30,3 +36,7 @@ func (internalProxyAuthRequired) ClientError() {
 func (internalProxyAuthRequired) ProxyAuthRequired() {
 	// Nothing here.
 }
+
+func (receiver internalProxyAuthRequired) Unwrap() error {
+	return receiver.err
+}

proxyauthrequired_test.go

@@ -1,14 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestProxyAuthRequired(t *testing.T) {
-
-	var x ProxyAuthRequired = internalProxyAuthRequired{} // THIS IS THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should not happen.")
-	}
-}

requestedrangenotsatisfiable.go

@@ -1,5 +1,11 @@
 package errhttp
 
+var _ Error                        = internalRequestedRangeNotSatisfiable{}
+var _ ClientError                  = internalRequestedRangeNotSatisfiable{}
+var _ RequestedRangeNotSatisfiable = internalRequestedRangeNotSatisfiable{}
+
+var ErrRequestedRangeNotSatisfiable error = RequestedRangeNotSatisfiableWrap(nil)
+
 type RequestedRangeNotSatisfiable interface {
 	ClientError
 	RequestedRangeNotSatisfiable()
@@ -19,8 +25,8 @@ func (receiver internalRequestedRangeNotSatisfiable) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalRequestedRangeNotSatisfiable) Err() error {
+func (internalRequestedRangeNotSatisfiable) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalRequestedRangeNotSatisfiable) ClientError() {
@@ -30,3 +36,7 @@ func (internalRequestedRangeNotSatisfiable) ClientError() {
 func (internalRequestedRangeNotSatisfiable) RequestedRangeNotSatisfiable() {
 	// Nothing here.
 }
+
+func (receiver internalRequestedRangeNotSatisfiable) Unwrap() error {
+	return receiver.err
+}

requestedrangenotsatisfiable_test.go

@@ -1,14 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestRequestedRangeNotSatisfiable(t *testing.T) {
-
-	var x RequestedRangeNotSatisfiable = internalRequestedRangeNotSatisfiable{} // THIS IS THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should not happen.")
-	}
-}

requestentitytoolarge.go

@@ -1,5 +1,11 @@
 package errhttp
 
+var _ Error                 = internalRequestEntityTooLarge{}
+var _ ClientError           = internalRequestEntityTooLarge{}
+var _ RequestEntityTooLarge = internalRequestEntityTooLarge{}
+
+var ErrRequestEntityTooLarge error = RequestEntityTooLargeWrap(nil)
+
 type RequestEntityTooLarge interface {
 	ClientError
 	RequestEntityTooLarge()
@@ -19,8 +25,8 @@ func (receiver internalRequestEntityTooLarge) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalRequestEntityTooLarge) Err() error {
+func (internalRequestEntityTooLarge) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalRequestEntityTooLarge) ClientError() {
@@ -30,3 +36,7 @@ func (internalRequestEntityTooLarge) ClientError() {
 func (internalRequestEntityTooLarge) RequestEntityTooLarge() {
 	// Nothing here.
 }
+
+func (receiver internalRequestEntityTooLarge) Unwrap() error {
+	return receiver.err
+}

requestentitytoolarge_test.go

@@ -1,14 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestRequestEntityTooLarge(t *testing.T) {
-
-	var x RequestEntityTooLarge = internalRequestEntityTooLarge{} // THIS IS THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should not happen.")
-	}
-}

requestheaderfieldstoolarge.go

@@ -1,8 +1,13 @@
 package errhttp
 
+var _ Error                       = internalRequestHeaderFieldsTooLarge{}
+var _ ClientError                 = internalRequestHeaderFieldsTooLarge{}
+var _ RequestHeaderFieldsTooLarge = internalRequestHeaderFieldsTooLarge{}
+
+var ErrRequestHeaderFieldsTooLarge error = RequestHeaderFieldsTooLargeWrap(nil)
+
 type RequestHeaderFieldsTooLarge interface {
-	error
+	ClientError
-	Err() error
 	RequestHeaderFieldsTooLarge()
 }
 
@@ -20,8 +25,8 @@ func (receiver internalRequestHeaderFieldsTooLarge) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalRequestHeaderFieldsTooLarge) Err() error {
+func (internalRequestHeaderFieldsTooLarge) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalRequestHeaderFieldsTooLarge) ClientError() {
@@ -31,3 +36,7 @@ func (internalRequestHeaderFieldsTooLarge) ClientError() {
 func (internalRequestHeaderFieldsTooLarge) RequestHeaderFieldsTooLarge() {
 	// Nothing here.
 }
+
+func (receiver internalRequestHeaderFieldsTooLarge) Unwrap() error {
+	return receiver.err
+}

requestheaderfieldstoolarge_test.go

@@ -1,14 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestRequestHeaderFieldsTooLarge(t *testing.T) {
-
-	var x RequestHeaderFieldsTooLarge = internalRequestHeaderFieldsTooLarge{} // THIS IS THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should not happen.")
-	}
-}

requesttimeout.go

@@ -1,8 +1,13 @@
 package errhttp
 
+var _ Error          = internalRequestTimeout{}
+var _ ClientError    = internalRequestTimeout{}
+var _ RequestTimeout = internalRequestTimeout{}
+
+var ErrRequestTimeout error = RequestTimeoutWrap(nil)
+
 type RequestTimeout interface {
-	error
+	ClientError
-	Err() error
 	RequestTimeout()
 }
 
@@ -20,8 +25,8 @@ func (receiver internalRequestTimeout) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalRequestTimeout) Err() error {
+func (internalRequestTimeout) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalRequestTimeout) ClientError() {
@@ -31,3 +36,7 @@ func (internalRequestTimeout) ClientError() {
 func (internalRequestTimeout) RequestTimeout() {
 	// Nothing here.
 }
+
+func (receiver internalRequestTimeout) Unwrap() error {
+	return receiver.err
+}

requesttimeout_test.go

@@ -1,14 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestRequestTimeout(t *testing.T) {
-
-	var x RequestTimeout = internalRequestTimeout{} // THIS IS THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should not happen.")
-	}
-}

requesturitoolong.go

@@ -1,8 +1,13 @@
 package errhttp
 
+var _ Error             = internalRequestURITooLong{}
+var _ ClientError       = internalRequestURITooLong{}
+var _ RequestURITooLong = internalRequestURITooLong{}
+
+var ErrRequestURITooLong error = RequestURITooLongWrap(nil)
+
 type RequestURITooLong interface {
-	error
+	ClientError
-	Err() error
 	RequestURITooLong()
 }
 
@@ -20,8 +25,8 @@ func (receiver internalRequestURITooLong) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalRequestURITooLong) Err() error {
+func (internalRequestURITooLong) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalRequestURITooLong) ClientError() {
@@ -31,3 +36,7 @@ func (internalRequestURITooLong) ClientError() {
 func (internalRequestURITooLong) RequestURITooLong() {
 	// Nothing here.
 }
+
+func (receiver internalRequestURITooLong) Unwrap() error {
+	return receiver.err
+}

requesturitoolong_test.go

@@ -1,14 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestRequestURITooLong(t *testing.T) {
-
-	var x RequestURITooLong = internalRequestURITooLong{} // THIS IS THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should not happen.")
-	}
-}

servererror_test.go

@@ -1,26 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestServerError(t *testing.T) {
-
-	var x ServerError
-
-	x = internalInternalServerError{}           // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalNotImplemented{}                // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalBadGateway{}                    // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalServiceUnavailable{}            // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalGatewayTimeout{}                // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalHTTPVersionNotSupported{}       // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalVariantAlsoNegotiates{}         // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalInsufficientStorage{}           // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalLoopDetected{}                  // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalNotExtended{}                   // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-	x = internalNetworkAuthenticationRequired{} // THESE ARE THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should never happen.")
-	}
-}

serviceunavailable.go

@@ -1,5 +1,11 @@
 package errhttp
 
+var _ Error              = internalServiceUnavailable{}
+var _ ServerError        = internalServiceUnavailable{}
+var _ ServiceUnavailable = internalServiceUnavailable{}
+
+var ErrServiceUnavailable error = ServiceUnavailableWrap(nil)
+
 type ServiceUnavailable interface {
 	ServerError
 	ServiceUnavailable()
@@ -19,8 +25,8 @@ func (receiver internalServiceUnavailable) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalServiceUnavailable) Err() error {
+func (internalServiceUnavailable) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalServiceUnavailable) ServerError() {
@@ -30,3 +36,7 @@ func (internalServiceUnavailable) ServerError() {
 func (internalServiceUnavailable) ServiceUnavailable() {
 	// Nothing here.
 }
+
+func (receiver internalServiceUnavailable) Unwrap() error {
+	return receiver.err
+}

teapot.go

@@ -1,5 +1,11 @@
 package errhttp
 
+var _ Error       = internalTeapot{}
+var _ ClientError = internalTeapot{}
+var _ Teapot      = internalTeapot{}
+
+var ErrTeapot error = TeapotWrap(nil)
+
 type Teapot interface {
 	ClientError
 	Teapot()
@@ -19,8 +25,8 @@ func (receiver internalTeapot) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalTeapot) Err() error {
+func (internalTeapot) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalTeapot) ClientError() {
@@ -30,3 +36,7 @@ func (internalTeapot) ClientError() {
 func (internalTeapot) Teapot() {
 	// Nothing here.
 }
+
+func (receiver internalTeapot) Unwrap() error {
+	return receiver.err
+}

teapot_test.go

@@ -1,14 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestTeapot(t *testing.T) {
-
-	var x Teapot = internalTeapot{} // THIS IS THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should not happen.")
-	}
-}

toomanyrequests.go

@@ -1,5 +1,11 @@
 package errhttp
 
+var _ Error           = internalTooManyRequests{}
+var _ ClientError     = internalTooManyRequests{}
+var _ TooManyRequests = internalTooManyRequests{}
+
+var ErrTooManyRequests error = TooManyRequestsWrap(nil)
+
 type TooManyRequests interface {
 	ClientError
 	TooManyRequests()
@@ -19,8 +25,8 @@ func (receiver internalTooManyRequests) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalTooManyRequests) Err() error {
+func (internalTooManyRequests) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalTooManyRequests) ClientError() {
@@ -30,3 +36,7 @@ func (internalTooManyRequests) ClientError() {
 func (internalTooManyRequests) TooManyRequests() {
 	// Nothing here.
 }
+
+func (receiver internalTooManyRequests) Unwrap() error {
+	return receiver.err
+}

toomanyrequests_test.go

@@ -1,14 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestTooManyRequests(t *testing.T) {
-
-	var x TooManyRequests = internalTooManyRequests{} // THIS IS THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should not happen.")
-	}
-}

unauthorized.go

@@ -1,5 +1,11 @@
 package errhttp
 
+var _ Error        = internalUnauthorized{}
+var _ ClientError  = internalUnauthorized{}
+var _ Unauthorized = internalUnauthorized{}
+
+var ErrUnauthorized error = UnauthorizedWrap(nil)
+
 type Unauthorized interface {
 	ClientError
 	Unauthorized()
@@ -19,8 +25,8 @@ func (receiver internalUnauthorized) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalUnauthorized) Err() error {
+func (internalUnauthorized) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalUnauthorized) ClientError() {
@@ -30,3 +36,7 @@ func (internalUnauthorized) ClientError() {
 func (internalUnauthorized) Unauthorized() {
 	// Nothing here.
 }
+
+func (receiver internalUnauthorized) Unwrap() error {
+	return receiver.err
+}

unauthorized_test.go

@@ -1,14 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestUnauthorized(t *testing.T) {
-
-	var x Unauthorized = internalUnauthorized{} // THIS IS THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should not happen.")
-	}
-}

unavailableforlegalreasons.go

@@ -1,5 +1,11 @@
 package errhttp
 
+var _ Error                      = internalUnavailableForLegalReasons{}
+var _ ClientError                = internalUnavailableForLegalReasons{}
+var _ UnavailableForLegalReasons = internalUnavailableForLegalReasons{}
+
+var ErrUnavailableForLegalReasons error = UnavailableForLegalReasonsWrap(nil)
+
 type UnavailableForLegalReasons interface {
 	ClientError
 	UnavailableForLegalReasons()
@@ -19,8 +25,8 @@ func (receiver internalUnavailableForLegalReasons) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalUnavailableForLegalReasons) Err() error {
+func (internalUnavailableForLegalReasons) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalUnavailableForLegalReasons) ClientError() {
@@ -31,3 +37,6 @@ func (internalUnavailableForLegalReasons) UnavailableForLegalReasons() {
 	// Nothing here.
 }
 
+func (receiver internalUnavailableForLegalReasons) Unwrap() error {
+	return receiver.err
+}

unavailableforlegalreasons_test.go

@@ -1,14 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestUnavailableForLegalReasons(t *testing.T) {
-
-	var x UnavailableForLegalReasons = internalUnavailableForLegalReasons{} // THIS IS THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should not happen.")
-	}
-}

unprocessableentity.go

@@ -1,5 +1,11 @@
 package errhttp
 
+var _ Error               = internalUnprocessableEntity{}
+var _ ClientError         = internalUnprocessableEntity{}
+var _ UnprocessableEntity = internalUnprocessableEntity{}
+
+var ErrUnprocessableEntity error = UnprocessableEntityWrap(nil)
+
 type UnprocessableEntity interface {
 	ClientError
 	UnprocessableEntity()
@@ -19,8 +25,8 @@ func (receiver internalUnprocessableEntity) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalUnprocessableEntity) Err() error {
+func (internalUnprocessableEntity) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalUnprocessableEntity) ClientError() {
@@ -30,3 +36,7 @@ func (internalUnprocessableEntity) ClientError() {
 func (internalUnprocessableEntity) UnprocessableEntity() {
 	// Nothing here.
 }
+
+func (receiver internalUnprocessableEntity) Unwrap() error {
+	return receiver.err
+}

unprocessableentity_test.go

@@ -1,14 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestUnprocessableEntity(t *testing.T) {
-
-	var x UnprocessableEntity = internalUnprocessableEntity{} // THIS IS THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should not happen.")
-	}
-}

unsupportedmediatype.go

@@ -1,5 +1,11 @@
 package errhttp
 
+var _ Error                = internalUnsupportedMediaType{}
+var _ ClientError          = internalUnsupportedMediaType{}
+var _ UnsupportedMediaType = internalUnsupportedMediaType{}
+
+var ErrUnsupportedMediaType error = UnsupportedMediaTypeWrap(nil)
+
 type UnsupportedMediaType interface {
 	ClientError
 	UnsupportedMediaType()
@@ -19,8 +25,8 @@ func (receiver internalUnsupportedMediaType) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalUnsupportedMediaType) Err() error {
+func (internalUnsupportedMediaType) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalUnsupportedMediaType) ClientError() {
@@ -30,3 +36,7 @@ func (internalUnsupportedMediaType) ClientError() {
 func (internalUnsupportedMediaType) UnsupportedMediaType() {
 	// Nothing here.
 }
+
+func (receiver internalUnsupportedMediaType) Unwrap() error {
+	return receiver.err
+}

unsupportedmediatype_test.go

@@ -1,14 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestUnsupportedMediaType(t *testing.T) {
-
-	var x UnsupportedMediaType = internalUnsupportedMediaType{} // THIS IS THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should not happen.")
-	}
-}

upgraderequired.go

@@ -1,5 +1,11 @@
 package errhttp
 
+var _ Error           = internalUpgradeRequired{}
+var _ ClientError     = internalUpgradeRequired{}
+var _ UpgradeRequired = internalUpgradeRequired{}
+
+var ErrUpgradeRequired error = UpgradeRequiredWrap(nil)
+
 type UpgradeRequired interface {
 	ClientError
 	UpgradeRequired()
@@ -19,8 +25,8 @@ func (receiver internalUpgradeRequired) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalUpgradeRequired) Err() error {
+func (internalUpgradeRequired) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalUpgradeRequired) ClientError() {
@@ -30,3 +36,7 @@ func (internalUpgradeRequired) ClientError() {
 func (internalUpgradeRequired) UpgradeRequired() {
 	// Nothing here.
 }
+
+func (receiver internalUpgradeRequired) Unwrap() error {
+	return receiver.err
+}

upgraderequired_test.go

@@ -1,14 +0,0 @@
-package errhttp
-
-import (
-	"testing"
-)
-
-func TestUpgradeRequired(t *testing.T) {
-
-	var x UpgradeRequired = internalUpgradeRequired{} // THIS IS THE LINE THAT ACTUALLY MATTERS IN THIS TEST.
-
-	if nil == x {
-		t.Errorf("This should not happen.")
-	}
-}

uritoolong.go

@@ -0,0 +1,42 @@
+package errhttp
+
+var _ Error       = internalURITooLong{}
+var _ ClientError = internalURITooLong{}
+var _ URITooLong  = internalURITooLong{}
+
+var ErrURITooLong error = URITooLongWrap(nil)
+
+type URITooLong interface {
+	ClientError
+	URITooLong()
+}
+
+type internalURITooLong struct {
+	err error
+}
+
+func URITooLongWrap(err error) error {
+	return internalURITooLong{
+		err:err,
+	}
+}
+
+func (receiver internalURITooLong) Error() string {
+	return receiver.err.Error()
+}
+
+func (internalURITooLong) ErrHTTP() {
+	// Nothing here.
+}
+
+func (internalURITooLong) ClientError() {
+	// Nothing here.
+}
+
+func (internalURITooLong) URITooLong() {
+	// Nothing here.
+}
+
+func (receiver internalURITooLong) Unwrap() error {
+	return receiver.err
+}

variantaisonegotiates.go

@@ -1,10 +1,18 @@
 package errhttp
 
+var _ Error                 = internalVariantAlsoNegotiates{}
+var _ ServerError           = internalVariantAlsoNegotiates{}
+var _ VariantAlsoNegotiates = internalVariantAlsoNegotiates{}
+
+var ErrVariantAlsoNegotiates error = VariantAlsoNegotiatesWrap(nil)
+
 type VariantAlsoNegotiates interface {
 	ServerError
 	VariantAlsoNegotiates()
 }
 
+var _ VariantAlsoNegotiates = internalVariantAlsoNegotiates{}
+
 type internalVariantAlsoNegotiates struct {
 	err error
 }
@@ -19,8 +27,8 @@ func (receiver internalVariantAlsoNegotiates) Error() string {
 	return receiver.err.Error()
 }
 
-func (receiver internalVariantAlsoNegotiates) Err() error {
+func (internalVariantAlsoNegotiates) ErrHTTP() {
-	return receiver.err
+	// Nothing here.
 }
 
 func (internalVariantAlsoNegotiates) ServerError() {
@@ -30,3 +38,7 @@ func (internalVariantAlsoNegotiates) ServerError() {
 func (internalVariantAlsoNegotiates) VariantAlsoNegotiates() {
 	// Nothing here.
 }
+
+func (receiver internalVariantAlsoNegotiates) Unwrap() error {
+	return receiver.err
+}