replace log.Fatal/os.Exit with error returns (#941)

* Use stdlib encoders
* Reduce some duplication
* Remove global pagination state
* Dedupe JSON detail types
* Bump golangci-lint

Reviewed-on: https://gitea.com/gitea/tea/pulls/941
Co-authored-by: techknowlogick <techknowlogick@gitea.com>
Co-committed-by: techknowlogick <techknowlogick@gitea.com>

modules/config/config.go

@@ -40,12 +40,21 @@ type LocalConfig struct {
 
 var (
 	// config contain if loaded local tea config
-	config         LocalConfig
-	loadConfigOnce sync.Once
+	config                 LocalConfig
+	loadConfigOnce         sync.Once
+	configPathMu           sync.Mutex
+	configPathTestOverride string
 )
 
 // GetConfigPath return path to tea config file
 func GetConfigPath() string {
+	configPathMu.Lock()
+	override := configPathTestOverride
+	configPathMu.Unlock()
+	if override != "" {
+		return override
+	}
+
 	configFilePath, err := xdg.ConfigFile("tea/config.yml")
 
 	var exists bool
@@ -71,6 +80,13 @@ func GetConfigPath() string {
 	return configFilePath
 }
 
+// SetConfigPathForTesting overrides the config path used by helpers in tests.
+func SetConfigPathForTesting(path string) {
+	configPathMu.Lock()
+	configPathTestOverride = path
+	configPathMu.Unlock()
+}
+
 // GetPreferences returns preferences based on the config file
 func GetPreferences() Preferences {
 	_ = loadConfig()