refactor(live-atc): extract normalizeManualFreq to shared/utils, add tests

Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>

app/pages/live-atc.vue

@@ -1523,6 +1523,7 @@ import { loadPizzicatoLite } from '../../shared/utils/pizzicatoLite'
 import type { PizzicatoLite } from '../../shared/utils/pizzicatoLite'
 import { createNoiseGenerators, getReadabilityProfile } from '../../shared/utils/radioEffects'
 import { createAtisAudioLoop, type AtisAudioLoop } from '../../shared/utils/atisAudioLoop'
+import { normalizeManualFreq } from '../../shared/utils/frequency'
 import type {
   CandidateTraceElimination,
   CandidateTraceEntry,
@@ -4937,17 +4938,6 @@ const onPresetSelectStandby = (opt: { value: string | number }) => {
 const manualFreqActive = ref('')
 const manualFreqStandby = ref('')
 
-// Accepts inputs like "121.5", "121,500" or "118" and normalises to a valid
-// VHF airband frequency string (118.000–136.975). Returns null when invalid so
-// callers/UI can disable the action.
-function normalizeManualFreq(input: string): string | null {
-  const raw = input.trim().replace(',', '.')
-  if (!raw) return null
-  const num = Number(raw)
-  if (!Number.isFinite(num) || num < 118 || num >= 137) return null
-  return num.toFixed(3)
-}
-
 function applyManualFrequency(target: 'active' | 'standby', close?: () => void) {
   const model = target === 'active' ? manualFreqActive : manualFreqStandby
   const freq = normalizeManualFreq(model.value)

shared/utils/frequency.ts

@@ -0,0 +1,10 @@
+// Accepts inputs like "121.5", "121,500" or "118" and normalises to a valid
+// VHF airband frequency string (118.000–136.975). Returns null when invalid so
+// callers/UI can disable the action.
+export function normalizeManualFreq(input: string): string | null {
+  const raw = input.trim().replace(',', '.')
+  if (!raw) return null
+  const num = Number(raw)
+  if (!Number.isFinite(num) || num < 118 || num >= 137) return null
+  return num.toFixed(3)
+}

tests/shared/frequency.test.ts

@@ -0,0 +1,26 @@
+import { test } from 'node:test'
+import assert from 'node:assert/strict'
+import { normalizeManualFreq } from '../../shared/utils/frequency.ts'
+
+test('normalizeManualFreq pads a bare integer to three decimals', () => {
+  assert.equal(normalizeManualFreq('121'), '121.000')
+})
+
+test('normalizeManualFreq accepts a comma decimal separator', () => {
+  assert.equal(normalizeManualFreq('121,3'), '121.300')
+})
+
+test('normalizeManualFreq rejects values outside the VHF airband', () => {
+  assert.equal(normalizeManualFreq('99.000'), null)
+  assert.equal(normalizeManualFreq('110.000'), null)
+  assert.equal(normalizeManualFreq('140.000'), null)
+})
+
+test('normalizeManualFreq accepts the lower airband boundary', () => {
+  assert.equal(normalizeManualFreq('118'), '118.000')
+})
+
+test('normalizeManualFreq rejects garbage input', () => {
+  assert.equal(normalizeManualFreq('abc'), null)
+  assert.equal(normalizeManualFreq(''), null)
+})