Update to use GitHub Actions, go.mod, and fix for Go 1.20 (#1)

.github/workflows/tests.yml

@@ -0,0 +1,36 @@
+name: Tests
+
+on:
+  push:
+    branches: [ master ]
+  pull_request:
+    branches: [ master ]
+
+jobs:
+  build-linux:
+    strategy:
+      matrix:
+        go: ['1.20', '1.19']
+        os: [ubuntu-latest, macos-latest, windows-latest]
+
+    name: Go ${{ matrix.go }} on ${{ matrix.os }}
+
+    runs-on: ${{ matrix.os }}
+
+    steps:
+    - uses: actions/checkout@v3
+
+    - name: Set up Go
+      uses: actions/setup-go@v4
+      with:
+        go-version: ${{ matrix.go }}
+
+    - name: Run tests
+      run: |
+        go version
+        go test -race ./...
+
+    - name: Test that binary builds
+      run: |
+        go build
+        ./gosnip "fmt.Println(time.Now())"

README.md

@@ -1,8 +1,7 @@
 # gosnip: run small snippets of Go code from the command line
 
-[![GoDoc](https://godoc.org/github.com/benhoyt/gosnip?status.png)](https://godoc.org/github.com/benhoyt/gosnip)
-[![TravisCI Build](https://travis-ci.org/benhoyt/gosnip.svg)](https://travis-ci.org/benhoyt/gosnip)
-[![AppVeyor Build](https://ci.appveyor.com/api/projects/status/github/benhoyt/gosnip?branch=master&svg=true)](https://ci.appveyor.com/project/benhoyt/gosnip)
+[![Documentation](https://pkg.go.dev/badge/github.com/benhoyt/gosnip)](https://pkg.go.dev/github.com/benhoyt/gosnip)
+[![GitHub Actions Build](https://github.com/benhoyt/gosnip/workflows/Tests/badge.svg)](https://github.com/benhoyt/gosnip/actions/workflows/tests.yml)
 
 Package gosnip is a tool that allows you to run small snippets of
 Go code from the command line.

go.mod

@@ -0,0 +1,10 @@
+module github.com/benhoyt/gosnip
+
+go 1.19
+
+require golang.org/x/tools v0.7.0
+
+require (
+	golang.org/x/mod v0.9.0 // indirect
+	golang.org/x/sys v0.6.0 // indirect
+)

go.sum

@@ -0,0 +1,6 @@
+golang.org/x/mod v0.9.0 h1:KENHtAZL2y3NLMYZeHY9DW8HW8V+kQyJsY/V9JlKvCs=
+golang.org/x/mod v0.9.0/go.mod h1:iBbtSCu2XBx23ZKBPSOrRkjjQPZFPuis4dIYUhu/chs=
+golang.org/x/sys v0.6.0 h1:MVltZSvRTcU2ljQOhs94SXPftV6DCNnZViHeQps87pQ=
+golang.org/x/sys v0.6.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
+golang.org/x/tools v0.7.0 h1:W4OVu8VVOaIO0yzWMNdepAulS7YfoS3Zabrm8DOXXU4=
+golang.org/x/tools v0.7.0/go.mod h1:4pg6aUX35JBAogB10C9AtvVL+qowtN4pT3CGSQex14s=

gosnip.go

@@ -1,53 +1,52 @@
 // Package gosnip is a tool that allows you to run small snippets of
 // Go code from the command line.
 //
-//     usage: gosnip [-d] [-i import ...] statements...
+//	usage: gosnip [-d] [-i import ...] statements...
 //
 // For simple uses, just specify one or more Go statements on the
 // command line, and gosnip will roll them into a full Go program and
 // run the result using "go run". Standard library imports and any
 // imports needed for packages in GOPATH are added automatically
 // (using the same logic as the "goimports" tool). Some examples:
 //
-//     $ gosnip 'fmt.Println("Hello world")'
-//     Hello world
+//	$ gosnip 'fmt.Println("Hello world")'
+//	Hello world
 //
-//     $ gosnip 'fmt.Println("Current time:")' 'fmt.Println(time.Now())'
-//     Current time:
-//     2018-11-24 16:18:47.101951 -0500 EST m=+0.000419239
+//	$ gosnip 'fmt.Println("Current time:")' 'fmt.Println(time.Now())'
+//	Current time:
+//	2018-11-24 16:18:47.101951 -0500 EST m=+0.000419239
 //
 // The -i flag allows you to specify an import explicitly, which may be
 // needed to select between ambiguous stdlib imports such as
 // "text/template" and "html/template" (multiple -i flags are
 // allowed). For example:
 //
-//     $ ./gosnip -i text/template 't, _ := template.New("w").Parse("{{ . }}\n")' \
-//                                 't.Execute(os.Stdout, "<b>")'
-//     <b>
-//     $ ./gosnip -i html/template 't, _ := template.New("w").Parse("{{ . }}\n")' \
-//                                 't.Execute(os.Stdout, "<b>")'
-//     &lt;b&gt;
+//	$ ./gosnip -i text/template 't, _ := template.New("w").Parse("{{ . }}\n")' \
+//	                            't.Execute(os.Stdout, "<b>")'
+//	<b>
+//	$ ./gosnip -i html/template 't, _ := template.New("w").Parse("{{ . }}\n")' \
+//	                            't.Execute(os.Stdout, "<b>")'
+//	&lt;b&gt;
 //
 // The -d flag turns on debug mode, which prints the full program on
 // stderr before running it. For example:
 //
-//     $ gosnip -d 'fmt.Println(time.Now())'
-//     package main
+//	$ gosnip -d 'fmt.Println(time.Now())'
+//	package main
 //
-//     import (
-//         "fmt"
-//         "time"
-//     )
+//	import (
+//	    "fmt"
+//	    "time"
+//	)
 //
-//     func main() {
-//         fmt.Println(time.Now())
-//     }
-//     2018-11-24 16:33:56.681024 -0500 EST m=+0.000383308
+//	func main() {
+//	    fmt.Println(time.Now())
+//	}
+//	2018-11-24 16:33:56.681024 -0500 EST m=+0.000383308
 //
 // The gosnip command-line tool is a thin wrapper around the
 // "sniplib" package. To run Go snippets in your Go programs, see the
 // sniplib docs.
-//
 package main
 
 import (
@@ -59,7 +58,7 @@ import (
 )
 
 const (
-	version = "v1.1.1"
+	version = "v1.2.0"
 )
 
 func main() {

sniplib/sniplib.go

@@ -10,7 +10,6 @@ import (
 	"os"
 	"os/exec"
 	"strings"
-	"syscall"
 
 	importspkg "golang.org/x/tools/imports"
 )
@@ -69,41 +68,31 @@ func Run(source string, stdin io.Reader, stdout, stderr io.Writer) error {
 	errBuf := &bytes.Buffer{}
 	cmd.Stderr = errBuf
 	err = cmd.Run()
-	if exitStatus(err) == 2 {
-		// "go run" exit status 2 means compile error, so filter the
-		// funky temp filename and extraneous "go run" comments
+	if err != nil {
+		// Ideally we'd only do this filtering on compile error, not program
+		// error, but it's hard to tell the difference ("go run" used to
+		// return exit code 2 for this, but since Go 1.20, it doesn't).
 		filterStderr(errBuf.Bytes(), stderr)
 		return err
 	}
 	_, _ = errBuf.WriteTo(stderr)
 	return err
 }
 
-// Return exit status from given exec error (there'll be a better way
-// to do this in Go 1.12!).
-func exitStatus(err error) int {
-	if err == nil {
-		return 0
-	}
-	if exitErr, ok := err.(*exec.ExitError); ok {
-		if status, ok := exitErr.Sys().(syscall.WaitStatus); ok {
-			return status.ExitStatus()
-		}
-	}
-	return 1
-}
-
 // Filter out extraneous output and temp file name from "go run"
 // output in case of compile error. Example "go run" output:
 //
-//     # command-line-arguments
-//     /var/folders/sz/thh6m7316b3gvvvmjp8qpdrm0000gp/T/gosnip_615300750.go:8:2: undefined: fmt.X
+//	# command-line-arguments
+//	/var/folders/sz/thh6m7316b3gvvvmjp8qpdrm0000gp/T/gosnip_615300750.go:8:2: undefined: fmt.X
 //
 // Output after filtering:
 //
-//     8:2: undefined: fmt.X
-//
+//	8:2: undefined: fmt.X
 func filterStderr(data []byte, writer io.Writer) {
+	if !bytes.Contains(data, []byte("# command-line-arguments")) {
+		writer.Write(data)
+		return
+	}
 	lines := bytes.Split(data, []byte("\n"))
 	for _, line := range lines {
 		if bytes.HasPrefix(line, []byte("# ")) {

sniplib/sniplib_test.go

@@ -6,6 +6,7 @@ import (
 	"bytes"
 	"fmt"
 	"os"
+	"regexp"
 	"strings"
 	"testing"
 
@@ -149,8 +150,8 @@ func main() {
 }
 `,
 			"",
-			"8:2: undefined: fmt.X\n",
-			"exit status 2",
+			"8:6: undefined: fmt.X\n",
+			"exit status [12]",
 		},
 		{
 			`package main
@@ -178,7 +179,7 @@ func main() {
 `,
 			"",
 			"4:2: undefined: foo\n",
-			"exit status 2",
+			"exit status [12]",
 		},
 	}
 	for _, test := range tests {
@@ -194,14 +195,26 @@ func main() {
 				t.Errorf("expected stderr %q, got %q", test.stderr, errBuf.String())
 			}
 			if err != nil {
-				if err.Error() != test.err {
-					t.Errorf("expected error %q, got %q", test.err, err.Error())
+				if !mustMatch(test.err, err.Error()) {
+					t.Errorf("expected error to match %q, got %q", test.err, err.Error())
+				}
+			} else {
+				if test.err != "" {
+					t.Errorf("expected error to match %q, got no error", test.err)
 				}
 			}
 		})
 	}
 }
 
+func mustMatch(pattern, s string) bool {
+	matched, err := regexp.MatchString(pattern, s)
+	if err != nil {
+		panic(err)
+	}
+	return matched
+}
+
 func ExampleToProgram() {
 	statements := []string{`fmt.Println("Hello world")`}
 	source, err := sniplib.ToProgram(statements, nil)