Fixed lint issues and missing documentation

internal/config/config.go

@@ -11,16 +11,23 @@ import (
 	"go.yaml.in/yaml/v3"
 )
 
+// EnvPrefix prefixes environment variables that override configuration keys,
+// e.g. JOBSEARCH_LOGGING_LEVEL for logging.level.
 const EnvPrefix string = "JOBSEARCH"
+
+// EtcConfigPath is searched for config.* when no config file is given, before
+// the working directory.
 const EtcConfigPath string = "/etc/job-search"
 
-// Each field's cfg tag must match the section's JSCK* constant.
+// JobSearchConfig is the application's whole configuration, one field per
+// section. Each field's cfg tag must match the section's JSCK* constant.
 type JobSearchConfig struct {
 	Logging JobSearchConfigLogging `cfg:"logging"`
 	Sources JobSearchConfigSources `cfg:"sources"`
 }
 
-// Default configuration, taken from the default struct tags
+// LoadDefaultConfig sets Viper's defaults from the configuration's default
+// struct tags.
 func LoadDefaultConfig() {
 	var conf JobSearchConfig
 	if err := applyDefaults(&conf); err != nil {
@@ -29,6 +36,8 @@ func LoadDefaultConfig() {
 	LoadToViper(conf)
 }
 
+// ---------- Section methods (see Section) ----------
+
 func (c JobSearchConfig) Map() map[string]any { return mapOf(c) }
 
 func (c JobSearchConfig) Flatten() map[string]any { return flattenOf("", c) }
@@ -45,7 +54,8 @@ func (c *JobSearchConfig) SetValue(key string, value any) error {
 	return setValue(c, key, value)
 }
 
-// Utility method for loading a configuration from Viper
+// LoadFromViper copies every key Viper knows that conf also has into conf.
+// Unknown keys are skipped; invalid values are logged and ignored.
 func LoadFromViper(conf *JobSearchConfig) {
 	keys := viper.AllKeys()
 	for idx := range keys {
@@ -71,7 +81,7 @@ func LoadFromViper(conf *JobSearchConfig) {
 	}
 }
 
-// Utility method for loading a configuration into Viper as defaults
+// LoadToViper sets every key of conf as a Viper default.
 func LoadToViper(conf JobSearchConfig) {
 	flatMap := conf.Flatten()
 	for key := range flatMap {
@@ -79,7 +89,8 @@ func LoadToViper(conf JobSearchConfig) {
 	}
 }
 
-// Converts configuration to a string in flat dotted format
+// String formats the configuration one "key = value <type>" line per key, with
+// dotted keys.
 func (conf JobSearchConfig) String() string {
 	var sb strings.Builder
 	for k, v := range conf.Flatten() {
@@ -89,14 +100,14 @@ func (conf JobSearchConfig) String() string {
 	return sb.String()
 }
 
-// Converts configuration to JSON
+// JSON formats the configuration as indented JSON.
 func (conf JobSearchConfig) JSON() string {
 	confMap := conf.Map()
 	jbytes, _ := json.MarshalIndent(confMap, "", "  ")
 	return string(jbytes)
 }
 
-// Converts configuration to YAML
+// YAML formats the configuration as YAML.
 func (conf JobSearchConfig) YAML() string {
 	confMap := conf.Map()
 	ybytes, _ := yaml.Marshal(confMap)