microsoft/TypeScript
1
0
Fork 0
mirror of https://github.com/microsoft/TypeScript.git synced 2026-05-27 22:39:59 -05:00
Code Issues Packages Projects Releases 212 Wiki Activity

fix(42368): omit converting jsx spread attributes to Object.assign for ES2018 and up (#42554)

Browse Source
This commit is contained in:
Oleksandr T
2021-02-19 03:06:08 +02:00
committed by GitHub
parent 0723904bfb
commit e961916217
11 changed files with 747 additions and 18 deletions
Download Patch File Download Diff File Expand all files Collapse all files

52
src/compiler/transformers/jsx.ts
View File

@@ -292,26 +292,38 @@ namespace ts {
// When there are no attributes, React wants "null"
}
else {
// Map spans of JsxAttribute nodes into object literals and spans
// of JsxSpreadAttribute nodes into expressions.
const segments = flatten<Expression | ObjectLiteralExpression>(
spanMap(attrs, isJsxSpreadAttribute, (attrs, isSpread) => isSpread
? map(attrs, transformJsxSpreadAttributeToExpression)
: factory.createObjectLiteralExpression(map(attrs, transformJsxAttributeToObjectLiteralElement))
)
);
if (isJsxSpreadAttribute(attrs[0])) {
// We must always emit at least one object literal before a spread
// argument.factory.createObjectLiteral
segments.unshift(factory.createObjectLiteralExpression());
const target = compilerOptions.target;
if (target && target >= ScriptTarget.ES2018) {
objectProperties = factory.createObjectLiteralExpression(
flatten<SpreadAssignment | PropertyAssignment>(
spanMap(attrs, isJsxSpreadAttribute, (attrs, isSpread) =>
isSpread ? map(attrs, transformJsxSpreadAttributeToSpreadAssignment) : map(attrs, transformJsxAttributeToObjectLiteralElement)
)
)
);
}
else {
// Map spans of JsxAttribute nodes into object literals and spans
// of JsxSpreadAttribute nodes into expressions.
const segments = flatten<Expression | ObjectLiteralExpression>(
spanMap(attrs, isJsxSpreadAttribute, (attrs, isSpread) => isSpread
? map(attrs, transformJsxSpreadAttributeToExpression)
: factory.createObjectLiteralExpression(map(attrs, transformJsxAttributeToObjectLiteralElement))
)
);
// Either emit one big object literal (no spread attribs), or
// a call to the __assign helper.
objectProperties = singleOrUndefined(segments);
if (!objectProperties) {
objectProperties = emitHelpers().createAssignHelper(segments);
if (isJsxSpreadAttribute(attrs[0])) {
// We must always emit at least one object literal before a spread
// argument.factory.createObjectLiteral
segments.unshift(factory.createObjectLiteralExpression());
}
// Either emit one big object literal (no spread attribs), or
// a call to the __assign helper.
objectProperties = singleOrUndefined(segments);
if (!objectProperties) {
objectProperties = emitHelpers().createAssignHelper(segments);
}
}
}
@@ -376,6 +388,10 @@ namespace ts {
return element;
}
function transformJsxSpreadAttributeToSpreadAssignment(node: JsxSpreadAttribute) {
return factory.createSpreadAssignment(visitNode(node.expression, visitor, isExpression));
}
function transformJsxSpreadAttributeToExpression(node: JsxSpreadAttribute) {
return visitNode(node.expression, visitor, isExpression);
}