[WIP] devconfig: use hujson to allow comments and trailing commas

Update the devbox.json (un)marshaling logic to make surgical changes to
devbox.json using the hujson package.

Author: gcurtis

go.mod

@@ -36,6 +36,7 @@ require (
 	github.com/spf13/cobra v1.7.0
 	github.com/spf13/pflag v1.0.5
 	github.com/stretchr/testify v1.8.4
+	github.com/tailscale/hujson v0.0.0-20221223112325-20486734a56a
 	github.com/wk8/go-ordered-map/v2 v2.1.8
 	github.com/zealic/go2node v0.1.0
 	go.jetpack.io/pkg v0.0.0-20231002215645-9afeb0623fd3

go.sum

@@ -321,6 +321,8 @@ github.com/stretchr/testify v1.7.1/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/
 github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
 github.com/stretchr/testify v1.8.4 h1:CcVxjf3Q8PM0mHUKJCdn+eZZtm5yQwehR5yeSVQQcUk=
 github.com/stretchr/testify v1.8.4/go.mod h1:sz/lmYIOXD/1dqDmKjjqLyZ2RngseejIcXlSw2iwfAo=
+github.com/tailscale/hujson v0.0.0-20221223112325-20486734a56a h1:SJy1Pu0eH1C29XwJucQo73FrleVK6t4kYz4NVhp34Yw=
+github.com/tailscale/hujson v0.0.0-20221223112325-20486734a56a/go.mod h1:DFSS3NAGHthKo1gTlmEcSBiZrRJXi28rLNd/1udP1c8=
 github.com/therootcompany/xz v1.0.1 h1:CmOtsn1CbtmyYiusbfmhmkpAAETj0wBIH6kCYaX+xzw=
 github.com/therootcompany/xz v1.0.1/go.mod h1:3K3UH1yCKgBneZYhuQUvJ9HPD19UEXEI0BWbMn8qNMY=
 github.com/ulikunitz/xz v0.5.6/go.mod h1:2bypXElzHzzJZwzH67Y6wb67pO62Rzfn7BSiF4ABRW8=

internal/devconfig/config.go

@@ -4,13 +4,16 @@
 package devconfig
 
 import (
+	"encoding/json"
 	"io"
 	"net/http"
+	"os"
 	"path/filepath"
 	"regexp"
 	"strings"
 
 	"github.com/pkg/errors"
+	"github.com/tailscale/hujson"
 	"go.jetpack.io/devbox/internal/boxcli/usererr"
 	"go.jetpack.io/devbox/internal/cuecfg"
 	"go.jetpack.io/devbox/internal/impl/shellcmd"
@@ -42,6 +45,8 @@ type Config struct {
 	// plugin: for built-in plugins
 	// This is a similar format to nix inputs
 	Include []string `json:"include,omitempty"`
+
+	ast *configAST
 }
 
 type shellConfig struct {
@@ -59,23 +64,33 @@ type Stage struct {
 	Command string `json:"command"`
 }
 
+const defaultJSON = `{
+  "packages": [],
+  "shell": {
+    "init_hook": [
+      "echo 'Welcome to devbox!' > /dev/null"
+    ],
+    "scripts": {
+      "test": [
+        "echo \"Error: no test specified\" && exit 1"
+      ]
+    }
+  }
+}
+`
+
 func DefaultConfig() *Config {
-	return &Config{
-		// initialize to empty slice instead of nil for consistent marshalling
-		Packages: Packages{Collection: []Package{}},
-		Shell: &shellConfig{
-			Scripts: map[string]*shellcmd.Commands{
-				"test": {
-					Cmds: []string{"echo \"Error: no test specified\" && exit 1"},
-				},
-			},
-			InitHook: &shellcmd.Commands{
-				Cmds: []string{
-					"echo 'Welcome to devbox!' > /dev/null",
-				},
-			},
-		},
+	cfg, err := LoadBytes([]byte(defaultJSON))
+	if err != nil {
+		panic(err)
 	}
+	cfg.ast.format()
+	return cfg
+}
+
+func (c *Config) Bytes() []byte {
+	c.ast.format()
+	return c.ast.root.Pack()
 }
 
 func (c *Config) Hash() (string, error) {
@@ -114,21 +129,36 @@ func (c *Config) InitHook() *shellcmd.Commands {
 
 // SaveTo writes the config to a file.
 func (c *Config) SaveTo(path string) error {
-	cfgPath := filepath.Join(path, DefaultName)
-	return cuecfg.WriteFile(cfgPath, c)
-}
-
-func readConfig(path string) (*Config, error) {
-	cfg := &Config{}
-	return cfg, errors.WithStack(cuecfg.ParseFile(path, cfg))
+	return os.WriteFile(path, c.Bytes(), 0o644)
 }
 
 // Load reads a devbox config file, and validates it.
 func Load(path string) (*Config, error) {
-	cfg, err := readConfig(path)
+	b, err := os.ReadFile(path)
+	if err != nil {
+		return nil, err
+	}
+	return LoadBytes(b)
+}
+
+func LoadBytes(b []byte) (*Config, error) {
+	jsonb, err := hujson.Standardize(b)
 	if err != nil {
 		return nil, err
 	}
+
+	ast, err := parseConfig(b)
+	if err != nil {
+		return nil, err
+	}
+	cfg := &Config{
+		Packages: Packages{ast: ast},
+		ast:      ast,
+	}
+	if err := json.Unmarshal(jsonb, cfg); err != nil {
+		println(string(jsonb))
+		return nil, err
+	}
 	return cfg, validateConfig(cfg)
 }
 
@@ -153,15 +183,6 @@ func LoadConfigFromURL(url string) (*Config, error) {
 	return cfg, validateConfig(cfg)
 }
 
-// WriteConfig saves a devbox config file.
-func WriteConfig(path string, cfg *Config) error {
-	err := validateConfig(cfg)
-	if err != nil {
-		return err
-	}
-	return cuecfg.WriteFile(path, cfg)
-}
-
 func validateConfig(cfg *Config) error {
 	fns := []func(cfg *Config) error{
 		ValidateNixpkg,
@@ -212,3 +233,10 @@ func ValidateNixpkg(cfg *Config) error {
 	}
 	return nil
 }
+
+func joinNameVersion(name, version string) string {
+	if version == "" {
+		return name
+	}
+	return name + "@" + version
+}

internal/devconfig/init.go

@@ -4,26 +4,28 @@
 package devconfig
 
 import (
+	"errors"
 	"fmt"
 	"io"
+	"os"
 	"path/filepath"
 	"strings"
 
 	"github.com/fatih/color"
 
-	"go.jetpack.io/devbox/internal/cuecfg"
 	"go.jetpack.io/devbox/internal/initrec"
 )
 
 func Init(dir string, writer io.Writer) (created bool, err error) {
-	cfgPath := filepath.Join(dir, DefaultName)
-
-	config := DefaultConfig()
+	created, err = initConfigFile(filepath.Join(dir, DefaultName))
+	if err != nil || !created {
+		return created, err
+	}
 
 	// package suggestion
 	pkgsToSuggest, err := initrec.Get(dir)
 	if err != nil {
-		return false, err
+		return created, err
 	}
 	if len(pkgsToSuggest) > 0 {
 		s := fmt.Sprintf("devbox add %s", strings.Join(pkgsToSuggest, " "))
@@ -33,6 +35,30 @@ func Init(dir string, writer io.Writer) (created bool, err error) {
 			color.HiYellowString(s),
 		)
 	}
+	return created, err
+}
+
+func initConfigFile(path string) (created bool, err error) {
+	f, err := os.OpenFile(path, os.O_RDWR|os.O_CREATE|os.O_EXCL, 0o644)
+	if errors.Is(err, os.ErrExist) {
+		return false, nil
+	}
+	if err != nil {
+		return false, err
+	}
+	defer func() {
+		if err != nil {
+			os.Remove(f.Name())
+		}
+	}()
 
-	return cuecfg.InitFile(cfgPath, config)
+	_, err = f.Write(DefaultConfig().Bytes())
+	if err != nil {
+		f.Close()
+		return false, err
+	}
+	if err := f.Close(); err != nil {
+		return false, err
+	}
+	return true, nil
 }