d1b8db1532
- Have the `jsx` helper do the `defaultProps` work instead of calling `defaultProps` inline. - Put `key` after `props` and make it optional. - Inline `children` as rest args instead of in the object. - Rename `createRawReactElement` to `jsx`. I wish I was kidding. Most of these are silly microoptimizations. In my test file (based off an internal RN app), this reduces the parsing overhead of inlining from around 1% to 0.1% in JSC and from 0.6% to 0.0% in V8 (compared to element inlining before this commit). Once parsed, the initial render with inlining is the same speed as not inlining in JSC and ~1% slower in V8. A second initial render in the same context (reusing the function objects, JIT, etc) is 2.0% faster in JSC and 5.5% faster in V8.
70 lines
2.0 KiB
JavaScript
70 lines
2.0 KiB
JavaScript
export default function ({ types: t }) {
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function hasRefOrSpread(attrs) {
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for (let i = 0; i < attrs.length; i++) {
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let attr = attrs[i];
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if (t.isJSXSpreadAttribute(attr)) return true;
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if (isJSXAttributeOfName(attr, "ref")) return true;
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}
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return false;
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}
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function isJSXAttributeOfName(attr, name) {
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return t.isJSXAttribute(attr) && t.isJSXIdentifier(attr.name, { name: name });
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}
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function getAttributeValue(attr) {
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let value = attr.value;
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if (!value) return t.identifier("true");
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if (t.isJSXExpressionContainer(value)) value = value.expression;
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return value;
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}
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return {
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visitor: {
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JSXElement(path, file) {
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let { node } = path;
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// filter
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let open = node.openingElement;
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if (hasRefOrSpread(open.attributes)) return;
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// init
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let props = t.objectExpression([]);
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let key = null;
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let type = open.name;
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if (t.isJSXIdentifier(type) && t.react.isCompatTag(type.name)) {
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type = t.stringLiteral(type.name);
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}
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function pushProp(objProps, key, value) {
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objProps.push(t.objectProperty(key, value));
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}
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// props
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for (let attr of (open.attributes: Array<Object>)) {
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if (isJSXAttributeOfName(attr, "key")) {
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key = getAttributeValue(attr);
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} else {
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let name = attr.name.name;
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let propertyKey = t.isValidIdentifier(name) ? t.identifier(name) : t.stringLiteral(name);
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pushProp(props.properties, propertyKey, getAttributeValue(attr));
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}
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}
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let args = [type, props];
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if (key || node.children.length) {
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let children = t.react.buildChildren(node);
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args.push(
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key || t.unaryExpression("void", t.numericLiteral(0), true),
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...children
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);
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}
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let el = t.callExpression(file.addHelper("jsx"), args);
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path.replaceWith(el);
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}
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}
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};
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}
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