[patch] added dedicated helper function for Internal error type as well

[-] updated readme with more info on helper functions for error types

Author: bnkamalesh

README.md

@@ -10,7 +10,7 @@
 
 Errors package is a drop-in replacement of the built-in Go errors package with no external dependencies. It lets you create errors of 11 different types which should handle most of the use cases. Some of them are a bit too specific for web applications, but useful nonetheless. Following are the primary features of this package:
 
-1. Custom error types
+1. Multiple (11) error types
 2. User friendly message
 3. File & line number prefixed to errors
 
@@ -20,7 +20,7 @@ In case of nested errors, the messages (in case of nesting with this package's e
 
 Go 1.13+
 
-### Custom error types
+### Available error types
 
 1. TypeInternal - is the error type for when there is an internal system error. e.g. Database errors
 2. TypeValidation - is the error type for when there is a validation error. e.g. invalid email address
@@ -34,6 +34,10 @@ Go 1.13+
 10. TypeSubscriptionExpired - is the error type for when a user's 'paid' account has expired
 11. TypeDownstreamDependencyTimedout - is the error type for when a request to a downstream dependent service times out
 
+Helper functions are available for all the error types. Each of them have 2 helper functions, one which accepts only a string, and the other which accepts an original error as well as a user friendly message.
+
+All the dedicated error type functions are documented [here](https://pkg.go.dev/github.com/bnkamalesh/errors?tab=doc#DownstreamDependencyTimedout). Names are consistent with the error type, e.g. errors.Internal(string) and errors.InternalErr(error, string)
+
 ### User friendly messages
 
 More often than not, when writing APIs, we'd want to respond with an easier to undersand user friendly message. Instead of returning the raw error. And log the raw error.

errors_test.go

@@ -142,8 +142,7 @@ func TestError_Type(t *testing.T) {
 	}
 }
 
-// ignoreTestSetDefaultType if run, will fail other tests because New's type would be reset
-func ignoreTestSetDefaultType(t *testing.T) {
+func TestSetDefaultType(t *testing.T) {
 	type args struct {
 		message string
 		e       errType

helper.go

@@ -28,6 +28,12 @@ func NewWithErrMsgType(e error, message string, etype errType) *Error {
 	return newerr(e, message, file, line, etype)
 }
 
+// Internal helper method for creation internal errors
+func Internal(message string) *Error {
+	_, file, line, _ := runtime.Caller(1)
+	return newerr(nil, message, file, line, TypeInternal)
+}
+
 // Validation is a helper function to create a new error of type TypeValidation
 func Validation(message string) *Error {
 	_, file, line, _ := runtime.Caller(1)

helper_test.go

@@ -101,7 +101,7 @@ func TestHelperFnsForAllTypes(t *testing.T) {
 		switch tt.args.eType {
 		case TypeInternal:
 			{
-				got = New(tt.args.message)
+				got = Internal(tt.args.message)
 				_, file, line, _ := runtime.Caller(0)
 				line--
 				want = newerr(nil, tt.args.message, file, line, TypeInternal)
@@ -482,7 +482,7 @@ func TestHTTPStatusCodeMessage(t *testing.T) {
 		{
 			name: "TypeInternal",
 			args: args{
-				err: New("unknown error occurred"),
+				err: Internal("unknown error occurred"),
 			},
 			want:  http.StatusInternalServerError,
 			want1: "unknown error occurred",
@@ -581,7 +581,7 @@ func TestHTTPStatusCodeMessage(t *testing.T) {
 		{
 			name: "TypeDownstreamDependencyTimedout",
 			args: args{
-				err: New("dependency timed out"),
+				err: DownstreamDependencyTimedout("dependency timed out"),
 			},
 			want:  http.StatusInternalServerError,
 			want1: "dependency timed out",
@@ -618,7 +618,7 @@ func TestWriteHTTP(t *testing.T) {
 		{
 			name: "TypeInternal",
 			args: args{
-				err: New("system error"),
+				err: Internal("system error"),
 				w:   httptest.NewRecorder(),
 			},
 			wantStatus:  http.StatusInternalServerError,