perf(core): use startsWith instead of indexOf (vuejs#989)

pikax · Apr 29, 2020 · cb12f43 · cb12f43
1 parent cad3757
commit cb12f43
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Showing 4 changed files with 4 additions and 4 deletions.
diff --git a/packages/runtime-core/src/componentEmits.ts b/packages/runtime-core/src/componentEmits.ts
@@ -73,7 +73,7 @@ export function emit(
  let handler = props[`on${capitalize(event)}`]
  // for v-model update:xxx events, also trigger kebab-case equivalent
  // for props passed via kebab-case
- if (!handler && event.indexOf('update:') === 0) {
+ if (!handler && event.startsWith('update:')) {
  event = hyphenate(event)
  handler = props[`on${capitalize(event)}`]
  }

diff --git a/packages/runtime-dom/src/modules/attrs.ts b/packages/runtime-dom/src/modules/attrs.ts
@@ -8,7 +8,7 @@ export function patchAttr(
  value: any,
  isSVG: boolean
 ) {
- if (isSVG && key.indexOf('xlink:') === 0) {
+ if (isSVG && key.startsWith('xlink:')) {
  if (value == null) {
  el.removeAttributeNS(xlinkNS, key.slice(6, key.length))
  } else {

diff --git a/packages/runtime-dom/src/patchProp.ts b/packages/runtime-dom/src/patchProp.ts
@@ -30,7 +30,7 @@ export const patchProp: RendererOptions<Node, Element>['patchProp'] = (
  default:
  if (isOn(key)) {
  // ignore v-model listeners
- if (key.indexOf('onUpdate:') < 0) {
+ if (!key.startsWith('onUpdate:')) {
  patchEvent(el, key, prevValue, nextValue, parentComponent)
  }
  } else if (

diff --git a/packages/shared/src/normalizeProp.ts b/packages/shared/src/normalizeProp.ts
@@ -29,7 +29,7 @@ export function stringifyStyle(
  }
  for (const key in styles) {
  const value = styles[key]
- const normalizedKey = key.indexOf(`--`) === 0 ? key : hyphenate(key)
+ const normalizedKey = key.startsWith(`--`) ? key : hyphenate(key)
  if (
  isString(value) ||
  (typeof value === 'number' && isNoUnitNumericStyleProp(normalizedKey))