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Fix edge case with rendering children as number 0 #18

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2 changes: 1 addition & 1 deletion src/vhtml.js
Original file line number Diff line number Diff line change
Expand Up @@ -42,7 +42,7 @@ export default function h(name, attrs) {
}
else while (stack.length) {
let child = stack.pop();
if (child) {
if (child !== undefined && child !== null) {
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This would allow <div>{true}</div> to render <div>true</div>. Do we want that? The VDOM libs ignore booleans.

In any case, this statement can compress to:

Suggested change
if (child !== undefined && child !== null) {
if (child != null) {

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It also allowed it before so we could leave as is or correct it, up to you. The shorter version while shorter is not explicit, it's better to always use the === and !== operators. Just my thoughts.

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I would concur with @dburles that being more explicit is often clearer. Also on the <div>{true}</div> debate mimicking the behaviour of React/Preact etc. seems intuitive.

if (child.pop) {
for (let i=child.length; i--; ) stack.push(child[i]);
}
Expand Down
30 changes: 28 additions & 2 deletions test/vhtml.js
Original file line number Diff line number Diff line change
Expand Up @@ -174,7 +174,34 @@ describe('vhtml', () => {
);
});

it('should support string fragments', () => {
it('should render a child of 0', () => {
function Child ({ children }) {
return <span>{children}</span>;
}
expect(
<div><Child>{0}</Child></div>
).to.equal(
'<div><span>0</span></div>'
);
});

it('should not attempt to render a child of null or undefined', () => {
function Child ({ children }) {
return <span>{children}</span>;
}
expect(
<div><Child>{null}</Child></div>
).to.equal(
'<div><span></span></div>'
);
expect(
<div><Child>{undefined}</Child></div>
).to.equal(
'<div><span></span></div>'
);
});

it('should support string fragments', () => {
expect(
h(null, null, "foo", "bar", "baz")
).to.equal(
Expand All @@ -189,5 +216,4 @@ describe('vhtml', () => {
'<p>foo</p><em>bar</em><div class="qqqqqq">baz</div>'
);
});

});