2018-01-29 22:59:06 +01:00

160 lines
4.0 KiB
JavaScript

import { types as t } from "@babel/core";
export default function(api, options) {
const { loose } = options;
function getSpreadLiteral(spread, scope) {
if (loose && !t.isIdentifier(spread.argument, { name: "arguments" })) {
return spread.argument;
} else {
return scope.toArray(spread.argument, true);
}
}
function hasSpread(nodes) {
for (let i = 0; i < nodes.length; i++) {
if (t.isSpreadElement(nodes[i])) {
return true;
}
}
return false;
}
function push(_props, nodes) {
if (!_props.length) return _props;
nodes.push(t.arrayExpression(_props));
return [];
}
function build(props: Array, scope) {
const nodes = [];
let _props = [];
for (const prop of props) {
if (t.isSpreadElement(prop)) {
_props = push(_props, nodes);
nodes.push(getSpreadLiteral(prop, scope));
} else {
_props.push(prop);
}
}
push(_props, nodes);
return nodes;
}
return {
visitor: {
ArrayExpression(path, state) {
const { node, scope } = path;
const elements = node.elements;
if (!hasSpread(elements)) return;
const nodes = build(elements, scope, state);
const first = nodes.shift();
if (nodes.length === 0 && first !== elements[0].argument) {
path.replaceWith(first);
return;
}
path.replaceWith(
t.callExpression(
t.memberExpression(first, t.identifier("concat")),
nodes,
),
);
},
CallExpression(path, state) {
const { node, scope } = path;
const args = node.arguments;
if (!hasSpread(args)) return;
const calleePath = path.get("callee");
if (calleePath.isSuper()) return;
let contextLiteral = scope.buildUndefinedNode();
node.arguments = [];
let nodes;
if (args.length === 1 && args[0].argument.name === "arguments") {
nodes = [args[0].argument];
} else {
nodes = build(args, scope, state);
}
const first = nodes.shift();
if (nodes.length) {
node.arguments.push(
t.callExpression(
t.memberExpression(first, t.identifier("concat")),
nodes,
),
);
} else {
node.arguments.push(first);
}
const callee = node.callee;
if (calleePath.isMemberExpression()) {
const temp = scope.maybeGenerateMemoised(callee.object);
if (temp) {
callee.object = t.assignmentExpression("=", temp, callee.object);
contextLiteral = temp;
} else {
contextLiteral = t.cloneNode(callee.object);
}
t.appendToMemberExpression(callee, t.identifier("apply"));
} else {
node.callee = t.memberExpression(node.callee, t.identifier("apply"));
}
if (t.isSuper(contextLiteral)) {
contextLiteral = t.thisExpression();
}
node.arguments.unshift(t.cloneNode(contextLiteral));
},
NewExpression(path, state) {
const { node, scope } = path;
let args = node.arguments;
if (!hasSpread(args)) return;
const nodes = build(args, scope, state);
const context = t.arrayExpression([t.nullLiteral()]);
args = t.callExpression(
t.memberExpression(context, t.identifier("concat")),
nodes,
);
path.replaceWith(
t.newExpression(
t.callExpression(
t.memberExpression(
t.memberExpression(
t.memberExpression(
t.identifier("Function"),
t.identifier("prototype"),
),
t.identifier("bind"),
),
t.identifier("apply"),
),
[node.callee, args],
),
[],
),
);
},
},
};
}