feat: implement gno bug (gnolang#1325)

Contains initial implementation of `gno bug` command.


![gno-bug](https://github.com/gnolang/gno/assets/37576387/c1357f99-dcfd-4d80-8b54-cd1a0caba12b)

Closes gnolang#733 

<details><summary>Contributors' checklist...</summary>

- [ ] Added new tests, or not needed, or not feasible
- [x] Provided an example (e.g. screenshot) to aid review or the PR is
self-explanatory
- [x] Updated the official documentation or not needed
- [x] No breaking changes were made, or a `BREAKING CHANGE: xxx` message
was included in the description
- [x] Added references to related issues and PRs
- [x] Provided any useful hints for running manual tests
- [x] Added new benchmarks to [generated
graphs](https://gnoland.github.io/benchmarks), if any. More info
[here](https://github.com/gnolang/gno/blob/master/.benchmarks/README.md).
</details>

---------

Co-authored-by: Manfred Touron <94029+moul@users.noreply.github.com>
Co-authored-by: Morgan <git@howl.moe>

.github/ISSUE_TEMPLATE/BUG-REPORT.md

@@ -1,6 +1,7 @@
 ---
 name: Bug Report Template
 about: Create a bug report
+# NOTE: keep in sync with gnovm/cmd/gno/bug.go
 ---
 
 ## [Subject of the issue]

docs/reference/go-gno-compatibility.md

@@ -287,7 +287,7 @@ Legend:
 
 | go command        | gno command      | comment                                                               |
 |-------------------|------------------|-----------------------------------------------------------------------|
-| go bug            |                  | see https://github.com/gnolang/gno/issues/733                         |
+| go bug            | gno bug          | same behavior                                                         |
 | go build          | gno build        | same intention, limited compatibility                                 |
 | go clean          | gno clean        | same intention, limited compatibility                                 |
 | go doc            | gno doc          | limited compatibility; see https://github.com/gnolang/gno/issues/522  |

gnovm/cmd/gno/bug.go

@@ -0,0 +1,165 @@
+package main
+
+import (
+	"context"
+	"flag"
+	"net/url"
+	"os/exec"
+	"runtime"
+	"runtime/debug"
+	"strings"
+	"text/template"
+	"time"
+
+	"github.com/gnolang/gno/tm2/pkg/commands"
+)
+
+// NOTE: keep in sync with .github/ISSUE_TEMPLATE/BUG-REPORT.md
+const bugTmpl = `## [Subject of the issue]
+
+### Description
+
+Describe your issue in as much detail as possible here
+
+### Your environment
+
+* go version {{.GoVersion}} {{.Os}}/{{.Arch}}
+* gno commit that causes this issue: {{.Commit}}
+
+### Steps to reproduce
+
+* Tell us how to reproduce this issue
+* Where the issue is, if you know
+* Which commands triggered the issue, if any
+
+### Expected behaviour
+
+Tell us what should happen
+
+### Actual behaviour
+
+Tell us what happens instead
+
+### Logs
+
+Please paste any logs here that demonstrate the issue, if they exist
+
+### Proposed solution
+
+If you have an idea of how to fix this issue, please write it down here, so we can begin discussing it
+
+`
+
+type bugCfg struct {
+	skipBrowser bool
+}
+
+func newBugCmd(io commands.IO) *commands.Command {
+	cfg := &bugCfg{}
+	return commands.NewCommand(
+		commands.Metadata{
+			Name:       "bug",
+			ShortUsage: "bug",
+			ShortHelp:  "Start a bug report",
+		},
+		cfg,
+		func(_ context.Context, args []string) error {
+			return execBug(cfg, args, io)
+		},
+	)
+}
+
+func (c *bugCfg) RegisterFlags(fs *flag.FlagSet) {
+	fs.BoolVar(
+		&c.skipBrowser,
+		"skip-browser",
+		false,
+		"do not open the browser",
+	)
+}
+
+func execBug(cfg *bugCfg, args []string, io commands.IO) error {
+	if len(args) != 0 {
+		return flag.ErrHelp
+	}
+
+	bugReportEnv := struct {
+		Os, Arch, GoVersion, Commit string
+	}{
+		runtime.GOOS,
+		runtime.GOARCH,
+		runtime.Version(),
+		getCommitHash(),
+	}
+
+	var buf strings.Builder
+	tmpl, err := template.New("bug.tmpl").Parse(bugTmpl)
+	if err != nil {
+		return err
+	}
+	tmpl.Execute(&buf, bugReportEnv)
+
+	body := buf.String()
+	url := "https://github.com/gnolang/gno/issues/new?body=" + url.QueryEscape(body)
+
+	if !cfg.skipBrowser && openBrowser(url) {
+		return nil
+	}
+
+	io.Println("Please file a new issue at github.com/gnolang/gno/issues/new using this template:")
+	io.Println()
+	io.Println(body)
+
+	return nil
+}
+
+// openBrowser opens a default web browser with the specified URL.
+func openBrowser(url string) bool {
+	var cmdArgs []string
+	switch runtime.GOOS {
+	case "windows":
+		cmdArgs = []string{"cmd", "/c", "start", url}
+	case "darwin":
+		cmdArgs = []string{"/usr/bin/open", url}
+	default: // "linux"
+		cmdArgs = []string{"xdg-open", url}
+	}
+
+	cmd := exec.Command(cmdArgs[0], cmdArgs[1:]...)
+	if cmd.Start() == nil && appearsSuccessful(cmd, 3*time.Second) {
+		return true
+	}
+
+	return false
+}
+
+// getCommitHash returns the commit hash from build info, or an
+// empty string if not found.
+func getCommitHash() string {
+	if info, ok := debug.ReadBuildInfo(); ok {
+		for _, setting := range info.Settings {
+			if setting.Key == "vcs.revision" {
+				return setting.Value
+			}
+		}
+	}
+	return ""
+}
+
+// appearsSuccessful reports whether the command appears to have run successfully.
+// If the command runs longer than the timeout, it's deemed successful.
+// If the command runs within the timeout, it's deemed successful if it exited cleanly.
+// Note: Taken from Go's `internal/browser“
+func appearsSuccessful(cmd *exec.Cmd, timeout time.Duration) bool {
+	errc := make(chan error, 1)
+	go func() {
+		errc <- cmd.Wait()
+	}()
+
+	select {
+	case <-time.After(timeout):
+		return true
+	case err := <-errc:
+		return err == nil
+	}
+}

gnovm/cmd/gno/bug_test.go

@@ -0,0 +1,21 @@
+package main
+
+import "testing"
+
+func TestBugApp(t *testing.T) {
+	tc := []testMainCase{
+		{
+			args:        []string{"bug -h"},
+			errShouldBe: "flag: help requested",
+		},
+		{
+			args:        []string{"bug unknown"},
+			errShouldBe: "flag: help requested",
+		},
+		{
+			args:                []string{"bug", "-skip-browser"},
+			stdoutShouldContain: "go version go1.",
+		},
+	}
+	testMainCaseRun(t, tc)
+}

gnovm/cmd/gno/main.go

@@ -33,6 +33,7 @@ func newGnocliCmd(io commands.IO) *commands.Command {
 		newReplCmd(),
 		newDocCmd(io),
 		newEnvCmd(io),
+		newBugCmd(io),
 		// fmt -- gofmt
 		// graph
 		// vendor -- download deps from the chain in vendor/
@@ -41,8 +42,7 @@ func newGnocliCmd(io commands.IO) *commands.Command {
 		// publish/release
 		// generate
 		// "vm" -- starts an in-memory chain that can be interacted with?
-		// bug -- start a bug report
-		// version -- show gno, golang versions
+		// version -- show cmd/gno, golang versions
 	)
 
 	return cmd