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Warn about reusing mutated attrs object - fixes #2719

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This commit is contained in:
Stephan Hoyer 2022-01-29 13:16:04 +01:00
parent 8ef7844f5a
commit b97fd59381
2 changed files with 20 additions and 0 deletions
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3
render/render.js
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@ -800,6 +800,9 @@ module.exports = function($window) {
if ("selectedIndex" in attrs) setAttr(vnode, "selectedIndex", null, attrs.selectedIndex, undefined)
}
function updateAttrs(vnode, old, attrs, ns) {
if (old && old === attrs) {
console.warn("Don't reuse attrs object, use new object for every redraw, this will throw in next major")
}
if (attrs != null) {
// If you assign an input type that is not supported by IE 11 with an assignment expression, an error will occur.
//

17
render/tests/test-attributes.js
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@ -756,4 +756,21 @@ o.spec("attributes", function() {
o(succeeded).equals(true)
})
})
o.spec("mutate attr object", function() {
o("warn when reusing attrs object", function() {
const _consoleWarn = console.warn
console.warn = o.spy()
const attrs = {className: "on"}
render(root, {tag: "input", attrs})
attrs.className = "off"
render(root, {tag: "input", attrs})
o(console.warn.callCount).equals(1)
o(console.warn.args[0]).equals("Don't reuse attrs object, use new object for every redraw, this will throw in next major")
console.warn = _consoleWarn
})
})
})