update builderFunc godoc, make naming more consistent

vimebu_func.go

@@ -5,10 +5,13 @@ import (
 	"strings"
 )
 
-// LabelCallback TODO:
 type LabelCallback func() (name, value string, escapeQuote bool)
 
-// WithLabel TODO:
+// WithLabel appends a pair of label name and label value to the builder.
+// Unlike [vimebu.WithLabelQuote], quotes inside the label value will not be escaped.
+// It's better suited for a label value where you control the input (either it is already sanitized, or it comes from a const or an enum for example).
+//
+// Panics if the label name or label value contain more than [vimebu.LabelNameMaxLen] or [vimebu.LabelValueMaxLen] bytes respectively.
 func WithLabel(name, value string) LabelCallback {
 	if len(name) > LabelNameMaxLen {
 		panic("label name contains too many bytes")
@@ -23,15 +26,20 @@ func WithLabel(name, value string) LabelCallback {
 	}
 }
 
-// WithLabelCond TODO:
+// WithLabelCond is a wrapper around [vimebu.WithLabel].
+// It allows you to conditionally add a label depending on the output of a predicate function.
+//
+// Panics if the label name or label value contain more than [vimebu.LabelNameMaxLen] or [vimebu.LabelValueMaxLen] bytes respectively.
 func WithLabelCond(fn func() bool, name, value string) LabelCallback {
 	if fn() {
 		return WithLabel(name, value)
 	}
 	return WithLabel("", "")
 }
 
-// WithLabelQuote TODO:
+// WithLabelQuote appends a pair of label name and label value to the builder. Quotes inside the label value will be escaped.
+//
+// Panics if the label name or label value contain more than [vimebu.LabelNameMaxLen] or [vimebu.LabelValueMaxLen] bytes respectively.
 func WithLabelQuote(name, value string) LabelCallback {
 	if len(name) > LabelNameMaxLen {
 		panic("label name contains too many bytes")
@@ -46,7 +54,10 @@ func WithLabelQuote(name, value string) LabelCallback {
 	}
 }
 
-// WithLabelQuoteCond TODO:
+// WithLabelQuoteCond is a wrapper around [vimebu.WithLabelQuote].
+// It allows you to conditionally add a label depending on the output of a predicate function.
+//
+// Panics if the label name or label value contain more than [vimebu.LabelNameMaxLen] or [vimebu.LabelValueMaxLen] bytes respectively.
 func WithLabelQuoteCond(fn func() bool, name, value string) LabelCallback {
 	if fn() {
 		return WithLabelQuote(name, value)
@@ -55,6 +66,9 @@ func WithLabelQuoteCond(fn func() bool, name, value string) LabelCallback {
 }
 
 // BuilderFunc is used to efficiently build a VictoriaMetrics metric.
+// It's backed by a bytes.Buffer to minimize memory copying.
+//
+// Panics if the name is empty, contains more than [vimebu.MetricNameMaxLen] bytes or if it contains a double quote.
 func BuilderFunc(name string, labels ...LabelCallback) string {
 	ln := len(name)
 	if ln == 0 {

vimebu_func_test.go

@@ -6,7 +6,7 @@ import (
 	"github.com/stretchr/testify/require"
 )
 
-func handleTestCaseFn(t *testing.T, tc testCase) {
+func handleTestCaseFunc(t *testing.T, tc testCase) {
 	labels := make([]LabelCallback, 0, len(tc.input.labels))
 
 	for _, label := range tc.input.labels {
@@ -21,16 +21,16 @@ func handleTestCaseFn(t *testing.T, tc testCase) {
 	require.Equal(t, tc.expected, result)
 }
 
-func TestBuilderFn(t *testing.T) {
+func TestBuilderFunc(t *testing.T) {
 	for _, tc := range testCases {
 		t.Run(tc.name, func(t *testing.T) {
 			if tc.mustPanic {
 				require.Panics(t, func() {
-					handleTestCaseFn(t, tc)
+					handleTestCaseFunc(t, tc)
 				})
 			} else {
 				require.NotPanics(t, func() {
-					handleTestCaseFn(t, tc)
+					handleTestCaseFunc(t, tc)
 				})
 			}
 		})
@@ -47,7 +47,7 @@ func TestLabelCond(t *testing.T) {
 	require.Equal(t, `test_cond{should="appear",present="/and/\"quoted\""}`, result)
 }
 
-func BenchmarkBuilderFnTestCases(b *testing.B) {
+func BenchmarkBuilderFuncTestCases(b *testing.B) {
 	for _, tc := range testCases {
 		if tc.mustPanic { // Skip test cases that panics as they will break the benchmarks.
 			continue