Naming, layout and comments: descriptive full-word names, one item per line in wrapped calls and literals, and doc comments on exported names

Short and single-letter names in application code become full words (tests
keep theirs). Wrapped calls, signatures and composite literals put one item
per line, and one-line function bodies are expanded. Exported names and
groups of constants get doc comments, and comments refer to the renamed
identifiers.

internal/config/config_test.go

@@ -70,7 +70,14 @@ func countSections(uses map[reflect.Type]int, section reflect.Type) {
 	}
 }
 
-func checkSections(t *testing.T, conf *JobSearchConfig, all map[string]any, uses map[reflect.Type]int, prefix string, section reflect.Value) {
+func checkSections(
+	t *testing.T,
+	conf *JobSearchConfig,
+	all map[string]any,
+	uses map[reflect.Type]int,
+	prefix string,
+	section reflect.Value,
+) {
 	for _, f := range fieldsOf(section.Type()) {
 		key := joinKey(prefix, f.key)
 		if isSectionList(f.typ) {
@@ -93,8 +100,12 @@ func checkSections(t *testing.T, conf *JobSearchConfig, all map[string]any, uses
 		}
 		for k := range keys {
 			if _, ok := all[joinKey(keyPrefix, k)]; !ok {
-				t.Errorf("%s.Flatten() key %q does not match its cfg tag %q",
-					name, k, key)
+				t.Errorf(
+					"%s.Flatten() key %q does not match its cfg tag %q",
+					name,
+					k,
+					key,
+				)
 			}
 		}
 
@@ -116,6 +127,7 @@ func checkSections(t *testing.T, conf *JobSearchConfig, all map[string]any, uses
 // checkSectionList checks the items of the list of sections at key implement
 // Section and that their methods agree with the list's value in all.
 func checkSectionList(t *testing.T, all map[string]any, key string, list reflect.Value) {
+	t.Helper()
 	name := list.Type().Elem().Name()
 	if !reflect.PointerTo(list.Type().Elem()).Implements(sectionType) {
 		t.Errorf("*%s (items of %s) does not implement Section", name, key)
@@ -145,7 +157,13 @@ func checkSectionList(t *testing.T, all map[string]any, key string, list reflect
 // checkSectionMethods checks section's Map, TypeOf, ValueOf and SetValue
 // against want, its keys and values, and kinds, their kinds.
 // Setting each key to its own value must succeed and leave section unchanged.
-func checkSectionMethods(t *testing.T, name string, section reflect.Value, want map[string]any, kinds map[string]reflect.Kind) {
+func checkSectionMethods(
+	t *testing.T,
+	name string,
+	section reflect.Value,
+	want map[string]any,
+	kinds map[string]reflect.Kind,
+) {
 	s := section.Addr().Interface().(Section)
 	if got := flattenMap("", s.Map()); !reflect.DeepEqual(got, want) {
 		t.Errorf("%s.Map() =\n%v\nwant\n%v", name, got, want)
@@ -184,14 +202,18 @@ func flattenMap(prefix string, m map[string]any) map[string]any {
 // checkEmbedded checks that structs embedded in a section, such as
 // JSCSourcesSource, implement Section too.
 func checkEmbedded(t *testing.T, section reflect.Type) {
+	t.Helper()
 	for i := 0; i < section.NumField(); i++ {
 		sf := section.Field(i)
 		if !sf.Anonymous || sf.Type.Kind() != reflect.Struct {
 			continue
 		}
 		if !reflect.PointerTo(sf.Type).Implements(sectionType) {
-			t.Errorf("*%s (embedded in %s) does not implement Section",
-				sf.Type.Name(), section.Name())
+			t.Errorf(
+				"*%s (embedded in %s) does not implement Section",
+				sf.Type.Name(),
+				section.Name(),
+			)
 		}
 		checkEmbedded(t, sf.Type)
 	}