From 25de59df88a72f506da527f24363f92bf9decea1 Mon Sep 17 00:00:00 2001
From: Robert Lin <robert@bobheadxi.dev>
Date: Fri, 27 May 2022 10:29:14 -0700
Subject: [PATCH] arg: introduce Arg alias, add note about quoting

---
 arg.go            | 8 ++++++++
 command.go        | 8 ++++++--
 exit_code_test.go | 6 +++---
 3 files changed, 17 insertions(+), 5 deletions(-)
 create mode 100644 arg.go

diff --git a/arg.go b/arg.go
new file mode 100644
index 0000000..f462d27
--- /dev/null
+++ b/arg.go
@@ -0,0 +1,8 @@
+package run
+
+import "bitbucket.org/creachadair/shell"
+
+// Arg quotes a value such that it gets treated as an argument by a command.
+//
+// It is currently an alias for shell.Quote
+func Arg(v string) string { return shell.Quote(v) }
diff --git a/command.go b/command.go
index f20b56c..4ac6521 100644
--- a/command.go
+++ b/command.go
@@ -26,10 +26,12 @@ type Command struct {
 }
 
 // Cmd joins all the parts and builds a command from it.
+//
+// Arguments are not implicitly quoted - to quote arguemnts, you can use Arg.
 func Cmd(ctx context.Context, parts ...string) *Command {
 	args, ok := shell.Split(strings.Join(parts, " "))
 	if !ok {
-		return &Command{buildError: errors.New("provided args are invalid")}
+		return &Command{buildError: errors.New("provided parts has unclosed quotes")}
 	}
 
 	return &Command{
@@ -39,8 +41,10 @@ func Cmd(ctx context.Context, parts ...string) *Command {
 }
 
 // Bash joins all the parts and builds a command from it to be run by 'bash -c'.
+//
+// Arguments are not implicitly quoted - to quote arguemnts, you can use Arg.
 func Bash(ctx context.Context, parts ...string) *Command {
-	return Cmd(ctx, "bash -c", shell.Quote(strings.Join(parts, " ")))
+	return Cmd(ctx, "bash -c", Arg(strings.Join(parts, " ")))
 }
 
 // Run starts command execution and returns Output, which defaults to combined output.
diff --git a/exit_code_test.go b/exit_code_test.go
index 290ed63..c9f15b1 100644
--- a/exit_code_test.go
+++ b/exit_code_test.go
@@ -4,21 +4,21 @@ import (
 	"context"
 	"fmt"
 
-	"bitbucket.org/creachadair/shell"
 	"github.com/sourcegraph/run"
 )
 
 func ExampleExitCode() {
 	ctx := context.Background()
 
-	err := run.Cmd(ctx, "bash -c", shell.Quote("exit 123")).Run().Wait()
+	err := run.Bash(ctx, "exit 123").Run().Wait()
 	fmt.Println(run.ExitCode(err))
 
-	err = run.Cmd(ctx, "echo 'hello world!'").Run().Wait()
+	err = run.Cmd(ctx, "echo", run.Arg("hello world!")).Run().Wait()
 	fmt.Println(run.ExitCode(err))
 
 	err = run.Cmd(ctx, "non-existing-binary").Run().Wait()
 	fmt.Println(run.ExitCode(err))
+
 	// Output:
 	// 123
 	// 0