ikawaha/errors

errors

The errors package is a libraries that adds context to errors.

contexter

The contexter adds key/value context and stack traces to the error.

Setting a value to an error:

err := errors.New("some error")
err = contextre.WithValue(err, "hello", "goodbye")

Getting the value associated with this error for key:

val, ok := contexter.Value(err, "hello")
fmt.Println(val, ok)

OUTPUT:
goodbye, true

Logging stack trace to an error:

err = contexter.WithStackTrace(err)

Retrieving the record from error:

trace, ok := contexter.StackTrace(err)
fmt.Println(trace)

OUTPUT:
error caused by fn1:
    /Users/ikawaha/go/src/github.com/ikawaha/verbose/error_test.go:12 github.com/ikawaha/verbose_test.fn1
    /Users/ikawaha/go/src/github.com/ikawaha/verbose/error_test.go:16 github.com/ikawaha/verbose_test.fn2
    /Users/ikawaha/go/src/github.com/ikawaha/verbose/error_test.go:20 github.com/ikawaha/verbose_test.TestWithStackTrace
    /usr/local/opt/go/libexec/src/testing/testing.go:1439 testing.tRunner
    /usr/local/opt/go/libexec/src/runtime/asm_amd64.s:1571 runtime.goexit

chainer

The chainer allows multiple errors to be chained (embedded) together and treated as a single error. It can also expand chained errors back into multiple errors.

Linking errors:

lhs := errors.New("lhs")
rhs := errors.New("rhs")
e := chainer.Append(lhs, rhs)

fmt.Println("errors.Is(e, lhs)=", errors.Is(e, lhs))
fmt.Println("errors.Is(e, rhs)=", errors.Is(e, rhs))
OUTPUT:
errors.Is(e, lhs)= true
errors.Is(e, rhs)= true

Yield multiple errors:

errs := chainer.Yield(e)
fmt.Println("chainer.Yield(e)=", errs)
OUTPUT:
chainer.Yield(e)== [lhs rhs]

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MIT