Remove default configuration and add fallback configuration

pkg/api/client_options.go

@@ -89,7 +89,7 @@ func optionsNeedResolution(opts ClientOptions) bool {
 }
 
 func resolveOptions(opts ClientOptions) (ClientOptions, error) {
-	cfg, _ := config.Read()
+	cfg, _ := config.Read(nil)
 	if opts.Host == "" {
 		opts.Host, _ = auth.DefaultHost()
 	}

pkg/api/http_client_test.go

@@ -247,7 +247,7 @@ func defaultHeaders() http.Header {
 func stubConfig(t *testing.T, cfgStr string) {
 	t.Helper()
 	old := config.Read
-	config.Read = func() (*config.Config, error) {
+	config.Read = func(_ *config.Config) (*config.Config, error) {
 		return config.ReadFromString(cfgStr), nil
 	}
 	t.Cleanup(func() {

pkg/auth/auth.go

@@ -55,7 +55,7 @@ func TokenForHost(host string) (string, string) {
 // file as fallback, but does not support reading the token from system keyring. Most consumers
 // should use TokenForHost.
 func TokenFromEnvOrConfig(host string) (string, string) {
-	cfg, _ := config.Read()
+	cfg, _ := config.Read(nil)
 	return tokenForHost(cfg, host)
 }
 
@@ -105,7 +105,7 @@ func tokenFromGh(path string, host string) (string, string) {
 // or from the configuration file.
 // Returns an empty string slice if no hosts are found.
 func KnownHosts() []string {
-	cfg, _ := config.Read()
+	cfg, _ := config.Read(nil)
 	return knownHosts(cfg)
 }
 
@@ -131,7 +131,7 @@ func knownHosts(cfg *config.Config) []string {
 // configuration file.
 // Returns "github.com", "default" if no viable host is found.
 func DefaultHost() (string, string) {
-	cfg, _ := config.Read()
+	cfg, _ := config.Read(nil)
 	return defaultHost(cfg)
 }
 

pkg/browser/browser.go

@@ -70,7 +70,7 @@ func resolveLauncher() string {
 	if ghBrowser := os.Getenv("GH_BROWSER"); ghBrowser != "" {
 		return ghBrowser
 	}
-	cfg, err := config.Read()
+	cfg, err := config.Read(nil)
 	if err == nil {
 		if cfgBrowser, _ := cfg.Get([]string{"browser"}); cfgBrowser != "" {
 			return cfgBrowser

pkg/browser/browser_test.go

@@ -89,7 +89,7 @@ func TestResolveLauncher(t *testing.T) {
 			}
 			if tt.config != nil {
 				old := config.Read
-				config.Read = func() (*config.Config, error) {
+				config.Read = func(_ *config.Config) (*config.Config, error) {
 					return tt.config, nil
 				}
 				defer func() { config.Read = old }()

pkg/config/config.go

@@ -119,18 +119,23 @@ func (c *Config) Set(keys []string, value string) {
 	m.SetEntry(keys[len(keys)-1], yamlmap.StringValue(value))
 }
 
+func (c *Config) deepCopy() *Config {
+	return ReadFromString(c.entries.String())
+}
+
 // Read gh configuration files from the local file system and
-// return a Config.
-var Read = func() (*Config, error) {
+// returns a Config. A copy of the fallback configuration will
+// be returned when there are no configuration files to load.
+// If there are no configuration files and no fallback configuration
+// an empty configuration will be returned.
+var Read = func(fallback *Config) (*Config, error) {
 	once.Do(func() {
-		cfg, loadErr = load(generalConfigFile(), hostsConfigFile())
+		cfg, loadErr = load(generalConfigFile(), hostsConfigFile(), fallback)
 	})
 	return cfg, loadErr
 }
 
 // ReadFromString takes a yaml string and returns a Config.
-// Note: This is only used for testing, and should not be
-// relied upon in production.
 func ReadFromString(str string) *Config {
 	m, _ := mapFromString(str)
 	if m == nil {
@@ -174,7 +179,7 @@ func Write(c *Config) error {
 	return nil
 }
 
-func load(generalFilePath, hostsFilePath string) (*Config, error) {
+func load(generalFilePath, hostsFilePath string, fallback *Config) (*Config, error) {
 	generalMap, err := mapFromFile(generalFilePath)
 	if err != nil && !os.IsNotExist(err) {
 		if errors.Is(err, yamlmap.ErrInvalidYaml) ||
@@ -184,8 +189,8 @@ func load(generalFilePath, hostsFilePath string) (*Config, error) {
 		return nil, err
 	}
 
-	if generalMap == nil || generalMap.Empty() {
-		generalMap, _ = mapFromString(defaultGeneralEntries)
+	if generalMap == nil {
+		generalMap = yamlmap.MapValue()
 	}
 
 	hostsMap, err := mapFromFile(hostsFilePath)
@@ -201,6 +206,10 @@ func load(generalFilePath, hostsFilePath string) (*Config, error) {
 		generalMap.AddEntry("hosts", hostsMap)
 	}
 
+	if generalMap.Empty() && fallback != nil {
+		return fallback.deepCopy(), nil
+	}
+
 	return &Config{entries: generalMap}, nil
 }
 
@@ -302,21 +311,3 @@ func writeFile(filename string, data []byte) (writeErr error) {
 	_, writeErr = file.Write(data)
 	return
 }
-
-var defaultGeneralEntries = `
-# What protocol to use when performing git operations. Supported values: ssh, https
-git_protocol: https
-# What editor gh should run when creating issues, pull requests, etc. If blank, will refer to environment.
-editor:
-# When to interactively prompt. This is a global config that cannot be overridden by hostname. Supported values: enabled, disabled
-prompt: enabled
-# A pager program to send command output to, e.g. "less". Set the value to "cat" to disable the pager.
-pager:
-# Aliases allow you to create nicknames for gh commands
-aliases:
-  co: pr checkout
-# The path to a unix socket through which send HTTP connections. If blank, HTTP traffic will be handled by net/http.DefaultTransport.
-http_unix_socket:
-# What web browser gh should use when opening URLs. If blank, will refer to environment.
-browser:
-`