Allow writing host-specific keys in a blank config

internal/config/config_file.go

@@ -7,6 +7,7 @@ import (
 	"io/ioutil"
 	"os"
 	"path"
+	"path/filepath"
 
 	"github.com/mitchellh/go-homedir"
 	"gopkg.in/yaml.v3"
@@ -49,7 +50,12 @@ var ReadConfigFile = func(fn string) ([]byte, error) {
 }
 
 var WriteConfigFile = func(fn string, data []byte) error {
-	cfgFile, err := os.OpenFile(ConfigFile(), os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0600) // cargo coded from setup
+	err := os.MkdirAll(filepath.Dir(fn), 0771)
+	if err != nil {
+		return err
+	}
+
+	cfgFile, err := os.OpenFile(fn, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0600) // cargo coded from setup
 	if err != nil {
 		return err
 	}

internal/config/config_file_test.go

@@ -63,7 +63,7 @@ hosts:
 	config, err := ParseConfig("config.yml")
 	eq(t, err, nil)
 	_, err = config.Get("github.com", "user")
-	eq(t, err, errors.New(`could not find config entry for "github.com"`))
+	eq(t, err, &NotFoundError{errors.New(`could not find config entry for "github.com"`)})
 }
 
 func Test_migrateConfig(t *testing.T) {

internal/config/config_setup.go

@@ -5,12 +5,10 @@ import (
 	"fmt"
 	"io"
 	"os"
-	"path/filepath"
 	"strings"
 
 	"github.com/cli/cli/api"
 	"github.com/cli/cli/auth"
-	"gopkg.in/yaml.v3"
 )
 
 const (
@@ -76,44 +74,20 @@ func setupConfigFile(filename string) (Config, error) {
 		return nil, err
 	}
 
-	// TODO this sucks. It precludes us laying out a nice config with comments and such.
-	type yamlConfig struct {
-		Hosts map[string]map[string]string
+	cfg := NewBlankConfig()
+	err = cfg.Set(oauthHost, "user", userLogin)
+	if err != nil {
+		return nil, err
 	}
-
-	yamlHosts := map[string]map[string]string{}
-	yamlHosts[oauthHost] = map[string]string{}
-	yamlHosts[oauthHost]["user"] = userLogin
-	yamlHosts[oauthHost]["oauth_token"] = token
-
-	defaultConfig := yamlConfig{
-		Hosts: yamlHosts,
-	}
-
-	err = os.MkdirAll(filepath.Dir(filename), 0771)
+	err = cfg.Set(oauthHost, "oauth_token", token)
 	if err != nil {
 		return nil, err
 	}
 
-	cfgFile, err := os.OpenFile(filename, os.O_RDWR|os.O_CREATE|os.O_TRUNC, 0600)
-	if err != nil {
-		return nil, err
+	if err = cfg.Write(); err == nil {
+		AuthFlowComplete()
 	}
-	defer cfgFile.Close()
-
-	yamlData, err := yaml.Marshal(defaultConfig)
-	if err != nil {
-		return nil, err
-	}
-	_, err = cfgFile.Write(yamlData)
-	if err != nil {
-		return nil, err
-	}
-
-	AuthFlowComplete()
-
-	// TODO cleaner error handling? this "should" always work given that we /just/ wrote the file...
-	return ParseConfig(filename)
+	return cfg, err
 }
 
 func getViewer(token string) (string, error) {

internal/config/config_type.go

@@ -88,6 +88,13 @@ func NewConfig(root *yaml.Node) Config {
 	}
 }
 
+func NewBlankConfig() Config {
+	return NewConfig(&yaml.Node{
+		Kind:    yaml.DocumentNode,
+		Content: []*yaml.Node{{Kind: yaml.MappingNode}},
+	})
+}
+
 // This type implements a Config interface and represents a config file on disk.
 type fileConfig struct {
 	ConfigMap
@@ -136,7 +143,10 @@ func (c *fileConfig) Set(hostname, key, value string) error {
 		return c.SetStringValue(key, value)
 	} else {
 		hostCfg, err := c.configForHost(hostname)
-		if err != nil {
+		var notFound *NotFoundError
+		if errors.As(err, &notFound) {
+			hostCfg = c.makeConfigForHost(hostname)
+		} else if err != nil {
 			return err
 		}
 		return hostCfg.SetStringValue(key, value)
@@ -154,7 +164,7 @@ func (c *fileConfig) configForHost(hostname string) (*HostConfig, error) {
 			return hc, nil
 		}
 	}
-	return nil, fmt.Errorf("could not find config entry for %q", hostname)
+	return nil, &NotFoundError{fmt.Errorf("could not find config entry for %q", hostname)}
 }
 
 func (c *fileConfig) Write() error {
@@ -186,6 +196,35 @@ func (c *fileConfig) hostEntries() ([]*HostConfig, error) {
 	return hostConfigs, nil
 }
 
+func (c *fileConfig) makeConfigForHost(hostname string) *HostConfig {
+	hostRoot := &yaml.Node{Kind: yaml.MappingNode}
+	hostCfg := &HostConfig{
+		Host:      hostname,
+		ConfigMap: ConfigMap{Root: hostRoot},
+	}
+
+	var notFound *NotFoundError
+	_, hostsEntry, err := c.FindEntry("hosts")
+	if errors.As(err, &notFound) {
+		hostsEntry = &yaml.Node{Kind: yaml.MappingNode}
+		c.Root.Content = append(c.Root.Content,
+			&yaml.Node{
+				Kind:  yaml.ScalarNode,
+				Value: "hosts",
+			}, hostsEntry)
+	} else if err != nil {
+		panic(err)
+	}
+
+	hostsEntry.Content = append(hostsEntry.Content,
+		&yaml.Node{
+			Kind:  yaml.ScalarNode,
+			Value: hostname,
+		}, hostRoot)
+
+	return hostCfg
+}
+
 func (c *fileConfig) parseHosts(hostsEntry *yaml.Node) ([]*HostConfig, error) {
 	hostConfigs := []*HostConfig{}
 

internal/config/config_type_test.go

@@ -0,0 +1,29 @@
+package config
+
+import (
+	"bytes"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func Test_fileConfig_Set(t *testing.T) {
+	cb := bytes.Buffer{}
+	StubWriteConfig(&cb, nil)
+
+	c := NewBlankConfig()
+	assert.NoError(t, c.Set("", "editor", "nano"))
+	assert.NoError(t, c.Set("github.com", "git_protocol", "ssh"))
+	assert.NoError(t, c.Set("example.com", "editor", "vim"))
+	assert.NoError(t, c.Set("github.com", "user", "hubot"))
+	assert.NoError(t, c.Write())
+
+	assert.Equal(t, `editor: nano
+hosts:
+    github.com:
+        git_protocol: ssh
+        user: hubot
+    example.com:
+        editor: vim
+`, cb.String())
+}