README
¶
errto 
This is a command to rewrite Go error handling code between the following packages:
errors(1.13+)golang.org/x/xerrorsgithub.com/pkg/errors
It rewrites the package imports and function calls using AST transformation. All whitespaces and comments are kept.
Getting Started
Install the latest release.
go get github.com/int128/errto
To rewrite the packages in the current working directory:
# rewrite with Go 1.13+ errors
errto go-errors ./...
# rewrite with golang.org/x/xerrors
errto xerrors ./...
# rewrite with github.com/pkg/errors
errto pkg-errors ./...
Example: rewrite with golang.org/x/xerrors
To rewrite package ./acceptance_test/testdata/pkgerrors with golang.org/x/xerrors:
% errto xerrors ./acceptance_test/testdata/pkgerrors
acceptance_test/testdata/pkgerrors/main.go:14:10: errors.Wrapf() -> xerrors.Errorf()
acceptance_test/testdata/pkgerrors/main.go:18:10: errors.Errorf() -> xerrors.Errorf()
acceptance_test/testdata/pkgerrors/main.go:21:10: errors.New() -> xerrors.New()
acceptance_test/testdata/pkgerrors/main.go: + import golang.org/x/xerrors
acceptance_test/testdata/pkgerrors/main.go: - import github.com/pkg/errors
--- writing 5 change(s) to acceptance_test/testdata/pkgerrors/main.go
You can see the following diff:
@@ -1,7 +1,7 @@
package main
import (
- "github.com/pkg/errors"
+ "golang.org/x/xerrors"
"log"
"os"
"strconv"
@@ -11,14 +11,14 @@ import (
func check(s string) error {
n, err := strconv.Atoi(s)
if err != nil {
- return errors.Wrapf(err, "invalid number")
+ return xerrors.Errorf("invalid number: %w", err)
}
if n < 0 {
// comment should be kept
- return errors.Errorf("number is negative: %d", n)
+ return xerrors.Errorf("number is negative: %d", n)
}
if n == 0 {
- return errors.New("number is zero")
+ return xerrors.New("number is zero")
}
return nil
}
You can check changes without actually writing files by --dry-run flag.
errto go-errors --dry-run ./...
It is recommended to commit files into a Git repository before running the command.
Usage
Usage:
errto [command]
Available Commands:
dump Dump AST of packages
go-errors Rewrite the packages with Go errors (fmt, errors)
help Help about any command
pkg-errors Rewrite the packages with github.com/pkg/errors
xerrors Rewrite the packages with golang.org/x/xerrors
Rewrite commands
The following syntax is supported.
| go-errors | xerrors | pkg-errors |
|---|---|---|
New("MESSAGE") |
New("MESSAGE") |
New("MESSAGE") |
Errorf("FORMAT", ...) |
Errorf("FORMAT", ...) |
Errorf("FORMAT", ...) |
Errorf("FORMAT: %w", ..., err) |
Errorf("FORMAT: %w", ..., err) |
Wrapf(err, "FORMAT", ...) |
Unwrap(err) |
Unwrap(err) |
Unwrap(err) 1 Cause(err) 2 |
As(err, v) |
As(err, v) |
As(err, v) 1 |
Is(err, v) |
Is(err, v) |
Is(err, v) 1 |
Errorf("%s: %w", "MSG", err) |
Errorf("%s: %w", "MSG", err) |
Wrap(err, "MSG") |
Errorf("%w", err) |
Errorf("%w", err) |
WithStack(err) |
Errorf("%s: %s", "MSG", err) |
Errorf("%s: %s", "MSG", err) |
WithMessage(err, "MSG") |
Errorf("FORMAT: %s", ..., err) |
Errorf("FORMAT: %s", ..., err) |
WithMessagef(err, "FORMAT", ...) |
1 Available in github.com/pkg/errors@v0.9.0 or later. See the release note for details.
2 Cause is replaced with Unwrap. Note that it may be incompatible.
Contributions
This is an open source software. Feel free to open issues and pull requests.
Documentation
¶
There is no documentation for this package.
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