From b33b40c9ffb6799e0564c34d22d2df164a8a1a2b Mon Sep 17 00:00:00 2001 From: Timon Ringwald Date: Wed, 9 Sep 2020 13:34:23 +0200 Subject: [PATCH] added README.md once again --- README.md | 86 +++++++++++++++++++++++++++++++++++++++++++++++++++++++ error.go | 6 +--- 2 files changed, 87 insertions(+), 5 deletions(-) create mode 100644 README.md diff --git a/README.md b/README.md new file mode 100644 index 0000000..4f28c38 --- /dev/null +++ b/README.md @@ -0,0 +1,86 @@ +# adverr + +Package adverr implements errors with call stack traces +as well as error templates for error equality + +## Installation +``` +go get git.tordarus.net/tordarus/adverr +``` + +## Usage examples + +### Importing +```go +import "git.tordarus.net/tordarus/adverr" +``` + +### Creating error templates +```go +var ( + ErrDoStuffFailed = adverr.NewErrTmpl("ErrDoStuffFailed", "Could'nt do stuff because of %s") +) +``` + +### Creating independent error (without error template) +```go +func doStuffWithIndependentErr() error { + return adverr.New("Could'nt do stuff") +} +``` + +### Creating error based on template +```go +func doStuff() error { + return ErrDoStuffFailed.New("reasons") +} +``` + +### Printing errors on stderr convieniently +```go +adverr.Print(myErr) +adverr.Println(myErr) +``` + +### Printing errors on stderr and exit with exit code +```go +adverr.Fatal(myErr, 1) +adverr.Fatalln(myErr, 1) +``` + +### Advantages of error templates +two errors made by the same template will return true when called with `errors.Is()` +```go +func doStuffAndFailWithMsg(msg string) error { + return ErrDoStuffFailed.New(msg) +} + +err1 := doStuffAndFailWithMsg("err1") +err2 := doStuffAndFailWithMsg("err2") + +fmt.Println(errors.Is(err1, err2)) // true +fmt.Println(err1 == err2) // false +fmt.Println(err1.Error() == err2.Error()) // false +``` + +### Wrapping errors +By wrapping errors, you can provide an error that is caused by another error. +A 'Caused by' section will be printed in the stack trace showing the original error. +You can also retrieve the original error by using `errors.Unwrap()` +```go +func doStuffWrapped() error { + err := doStuff() + if err != nil { + return adverr.Wrap("doStuffWrapped failed", err) + } + + return nil +} +``` + +### Retrieving call stack trace (for debugging purposes) +```go +fmt.Println(adverr.Trace()) +``` + +### \ No newline at end of file diff --git a/error.go b/error.go index bc99bae..e4f49e3 100644 --- a/error.go +++ b/error.go @@ -37,11 +37,7 @@ func errtype(err error) string { if e, ok := err.(*Error); ok && e.tmpl != nil { return errtype(e.tmpl) } else if tmpl, ok := err.(*ErrTmpl); ok { - t := reflect.TypeOf(tmpl) - for t.Kind() == reflect.Ptr { - t = t.Elem() - } - return t.PkgPath() + "." + tmpl.name + return tmpl.name } t := reflect.TypeOf(err)