d2format: Expose in CLI under fmt subcommand

Closes #289

autofmt.go

@@ -0,0 +1,36 @@
+package main
+
+import (
+	"bytes"
+	"context"
+
+	"oss.terrastruct.com/xdefer"
+
+	"oss.terrastruct.com/d2/d2format"
+	"oss.terrastruct.com/d2/d2parser"
+	"oss.terrastruct.com/d2/lib/xmain"
+)
+
+func autofmt(ctx context.Context, ms *xmain.State) (err error) {
+	defer xdefer.Errorf(&err, "autofmt failed")
+
+	ms.Opts = xmain.NewOpts(ms.Env, ms.Log, ms.Opts.Flags.Args()[1:])
+	if len(ms.Opts.Args) == 0 {
+		return xmain.UsageErrorf("fmt must be passed the file to be formatted")
+	} else if len(ms.Opts.Args) > 1 {
+		return xmain.UsageErrorf("fmt only accepts one argument for the file to be formatted")
+	}
+
+	inputPath := ms.Opts.Args[0]
+	input, err := ms.ReadPath(inputPath)
+	if err != nil {
+		return err
+	}
+
+	m, err := d2parser.Parse(inputPath, bytes.NewReader(input), nil)
+	if err != nil {
+		return err
+	}
+
+	return ms.WritePath(inputPath, []byte(d2format.Format(m)))
+}

ci/release/changelogs/next.md

@@ -1,5 +1,7 @@
 #### Features 🚀
 
+- autoformat is supported on the CLI with the `fmt` subcommand.
+  [#292](https://github.com/terrastruct/d2/pull/292)
 - Latex is now supported. See [docs](https://d2lang.com/tour/text) for more.
   [#229](https://github.com/terrastruct/d2/pull/229)
 - `direction` keyword is now supported to specify `up`, `down`, `right`, `left` layouts. See

ci/release/template/man/d2.1

@@ -12,6 +12,8 @@
 .Op Ar file.svg | file.png
 .Nm d2
 .Ar layout Op Ar name
+.Nm d2
+.Ar fmt Ar file.d2
 .Sh DESCRIPTION
 .Nm
 compiles and renders
@@ -75,6 +77,10 @@ Print version information and exit.
 Lists available layout engine options with short help.
 .It Ar layout Op Ar name
 Display long help for a particular layout engine.
+.It Ar fmt Ar file.d2
+Autoformat
+.Ar file.d2
+.Ns .
 .El
 .Sh SEE ALSO
 .Xr d2plugin-tala 1

help.go

@@ -15,7 +15,9 @@ import (
 
 func help(ms *xmain.State) {
 	fmt.Fprintf(ms.Stdout, `Usage:
-  %s [--watch=false] [--theme=0] file.d2 [file.svg | file.png]
+  %[1]s [--watch=false] [--theme=0] file.d2 [file.svg | file.png]
+  %[1]s layout [name]
+  %[1]s fmt file.d2
 
 %[1]s compiles and renders file.d2 to file.svg | file.png
 It defaults to file.svg if an output path is not provided.
@@ -29,10 +31,11 @@ Flags:
 
 Subcommands:
   %[1]s layout - Lists available layout engine options with short help
-  %[1]s layout [layout name] - Display long help for a particular layout engine
+  %[1]s layout [name] - Display long help for a particular layout engine
+  %[1]s fmt file.d2 - Autoformat file.d2
 
 See more docs and the source code at https://oss.terrastruct.com/d2
-`, ms.Name, ms.Opts.Defaults())
+`, filepath.Base(ms.Name), ms.Opts.Defaults())
 }
 
 func layoutHelp(ctx context.Context, ms *xmain.State) error {

main.go

@@ -65,18 +65,23 @@ func run(ctx context.Context, ms *xmain.State) (err error) {
 		return xmain.UsageErrorf("failed to parse flags: %v", err)
 	}
 
+	if errors.Is(err, pflag.ErrHelp) {
+		help(ms)
+		return nil
+	}
+
 	if len(ms.Opts.Flags.Args()) > 0 {
 		switch ms.Opts.Flags.Arg(0) {
 		case "layout":
 			return layoutHelp(ctx, ms)
+		case "fmt":
+			return autofmt(ctx, ms)
+		case "version":
+			fmt.Println(version.Version)
+			return nil
 		}
 	}
 
-	if errors.Is(err, pflag.ErrHelp) {
-		help(ms)
-		return nil
-	}
-
 	if *debugFlag {
 		ms.Env.Setenv("DEBUG", "1")
 	}
@@ -96,10 +101,6 @@ func run(ctx context.Context, ms *xmain.State) (err error) {
 	}
 
 	if len(ms.Opts.Flags.Args()) >= 1 {
-		if ms.Opts.Flags.Arg(0) == "version" {
-			fmt.Println(version.Version)
-			return nil
-		}
 		inputPath = ms.Opts.Flags.Arg(0)
 	}
 	if len(ms.Opts.Flags.Args()) >= 2 {