packages/babel-plugin-transform-react-jsx/src/transform-classic.js
import { declare } from "@babel/helper-plugin-utils";
import jsx from "@babel/plugin-syntax-jsx";
import helper from "@babel/helper-builder-react-jsx";
import { types as t } from "@babel/core";
const DEFAULT = {
pragma: "React.createElement",
pragmaFrag: "React.Fragment",
};
export default declare((api, options) => {
const THROW_IF_NAMESPACE =
options.throwIfNamespace === undefined ? true : !!options.throwIfNamespace;
const PRAGMA_DEFAULT = options.pragma || DEFAULT.pragma;
const PRAGMA_FRAG_DEFAULT = options.pragmaFrag || DEFAULT.pragmaFrag;
const PURE_ANNOTATION = options.pure;
const JSX_ANNOTATION_REGEX = /\*?\s*@jsx\s+([^\s]+)/;
const JSX_FRAG_ANNOTATION_REGEX = /\*?\s*@jsxFrag\s+([^\s]+)/;
// returns a closure that returns an identifier or memberExpression node
// based on the given id
const createIdentifierParser = (id: string) => () => {
return id
.split(".")
.map(name => t.identifier(name))
.reduce((object, property) => t.memberExpression(object, property));
};
const visitor = helper({
pre(state) {
const tagName = state.tagName;
const args = state.args;
if (t.react.isCompatTag(tagName)) {
args.push(t.stringLiteral(tagName));
} else {
args.push(state.tagExpr);
}
},
post(state, pass) {
state.callee = pass.get("jsxIdentifier")();
state.pure = PURE_ANNOTATION ?? pass.get("pragma") === DEFAULT.pragma;
},
throwIfNamespace: THROW_IF_NAMESPACE,
});
visitor.Program = {
enter(path, state) {
const { file } = state;
let pragma = PRAGMA_DEFAULT;
let pragmaFrag = PRAGMA_FRAG_DEFAULT;
let pragmaSet = !!options.pragma;
let pragmaFragSet = !!options.pragma;
if (file.ast.comments) {
for (const comment of (file.ast.comments: Array<Object>)) {
const jsxMatches = JSX_ANNOTATION_REGEX.exec(comment.value);
if (jsxMatches) {
pragma = jsxMatches[1];
pragmaSet = true;
}
const jsxFragMatches = JSX_FRAG_ANNOTATION_REGEX.exec(comment.value);
if (jsxFragMatches) {
pragmaFrag = jsxFragMatches[1];
pragmaFragSet = true;
}
}
}
state.set("jsxIdentifier", createIdentifierParser(pragma));
state.set("jsxFragIdentifier", createIdentifierParser(pragmaFrag));
state.set("usedFragment", false);
state.set("pragma", pragma);
state.set("pragmaSet", pragmaSet);
state.set("pragmaFragSet", pragmaFragSet);
},
exit(path, state) {
if (
state.get("pragmaSet") &&
state.get("usedFragment") &&
!state.get("pragmaFragSet")
) {
throw new Error(
"transform-react-jsx: pragma has been set but " +
"pragmaFrag has not been set",
);
}
},
};
visitor.JSXAttribute = function (path) {
if (t.isJSXElement(path.node.value)) {
path.node.value = t.jsxExpressionContainer(path.node.value);
}
};
return {
name: "transform-react-jsx",
inherits: jsx,
visitor,
};
});