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"use strict";
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.default = void 0;
exports.ensure = ensure;
exports.get = get;
exports.getDependencies = getDependencies;
exports.list = void 0;
exports.minVersion = minVersion;
var _traverse = require("@babel/traverse");
var _t = require("@babel/types");
var _helpers = require("./helpers");
const {
assignmentExpression,
cloneNode,
expressionStatement,
file,
identifier
} = _t;
function makePath(path) {
const parts = [];
for (; path.parentPath; path = path.parentPath) {
parts.push(path.key);
if (path.inList) parts.push(path.listKey);
}
return parts.reverse().join(".");
}
let FileClass = undefined;
function getHelperMetadata(file) {
const globals = new Set();
const localBindingNames = new Set();
const dependencies = new Map();
let exportName;
let exportPath;
const exportBindingAssignments = [];
const importPaths = [];
const importBindingsReferences = [];
const dependencyVisitor = {
ImportDeclaration(child) {
const name = child.node.source.value;
if (!_helpers.default[name]) {
throw child.buildCodeFrameError(`Unknown helper ${name}`);
}
if (child.get("specifiers").length !== 1 || !child.get("specifiers.0").isImportDefaultSpecifier()) {
throw child.buildCodeFrameError("Helpers can only import a default value");
}
const bindingIdentifier = child.node.specifiers[0].local;
dependencies.set(bindingIdentifier, name);
importPaths.push(makePath(child));
},
ExportDefaultDeclaration(child) {
const decl = child.get("declaration");
if (!decl.isFunctionDeclaration() || !decl.node.id) {
throw decl.buildCodeFrameError("Helpers can only export named function declarations");
}
exportName = decl.node.id.name;
exportPath = makePath(child);
},
ExportAllDeclaration(child) {
throw child.buildCodeFrameError("Helpers can only export default");
},
ExportNamedDeclaration(child) {
throw child.buildCodeFrameError("Helpers can only export default");
},
Statement(child) {
if (child.isImportDeclaration() || child.isExportDeclaration()) return;
child.skip();
}
};
const referenceVisitor = {
Program(path) {
const bindings = path.scope.getAllBindings();
Object.keys(bindings).forEach(name => {
if (name === exportName) return;
if (dependencies.has(bindings[name].identifier)) return;
localBindingNames.add(name);
});
},
ReferencedIdentifier(child) {
const name = child.node.name;
const binding = child.scope.getBinding(name);
if (!binding) {
globals.add(name);
} else if (dependencies.has(binding.identifier)) {
importBindingsReferences.push(makePath(child));
}
},
AssignmentExpression(child) {
const left = child.get("left");
if (!(exportName in left.getBindingIdentifiers())) return;
if (!left.isIdentifier()) {
throw left.buildCodeFrameError("Only simple assignments to exports are allowed in helpers");
}
const binding = child.scope.getBinding(exportName);
if (binding != null && binding.scope.path.isProgram()) {
exportBindingAssignments.push(makePath(child));
}
}
};
(0, _traverse.default)(file.ast, dependencyVisitor, file.scope);
(0, _traverse.default)(file.ast, referenceVisitor, file.scope);
if (!exportPath) throw new Error("Helpers must have a default export.");
exportBindingAssignments.reverse();
return {
globals: Array.from(globals),
localBindingNames: Array.from(localBindingNames),
dependencies,
exportBindingAssignments,
exportPath,
exportName,
importBindingsReferences,
importPaths
};
}
function permuteHelperAST(file, metadata, id, localBindings, getDependency) {
if (localBindings && !id) {
throw new Error("Unexpected local bindings for module-based helpers.");
}
if (!id) return;
const {
localBindingNames,
dependencies,
exportBindingAssignments,
exportPath,
exportName,
importBindingsReferences,
importPaths
} = metadata;
const dependenciesRefs = {};
dependencies.forEach((name, id) => {
dependenciesRefs[id.name] = typeof getDependency === "function" && getDependency(name) || id;
});
const toRename = {};
const bindings = new Set(localBindings || []);
localBindingNames.forEach(name => {
let newName = name;
while (bindings.has(newName)) newName = "_" + newName;
if (newName !== name) toRename[name] = newName;
});
if (id.type === "Identifier" && exportName !== id.name) {
toRename[exportName] = id.name;
}
const {
path
} = file;
const exp = path.get(exportPath);
const imps = importPaths.map(p => path.get(p));
const impsBindingRefs = importBindingsReferences.map(p => path.get(p));
const decl = exp.get("declaration");
if (id.type === "Identifier") {
exp.replaceWith(decl);
} else if (id.type === "MemberExpression") {
exportBindingAssignments.forEach(assignPath => {
const assign = path.get(assignPath);
assign.replaceWith(assignmentExpression("=", id, assign.node));
});
exp.replaceWith(decl);
path.pushContainer("body", expressionStatement(assignmentExpression("=", id, identifier(exportName))));
} else {
throw new Error("Unexpected helper format.");
}
Object.keys(toRename).forEach(name => {
path.scope.rename(name, toRename[name]);
});
for (const path of imps) path.remove();
for (const path of impsBindingRefs) {
const node = cloneNode(dependenciesRefs[path.node.name]);
path.replaceWith(node);
}
}
const helperData = Object.create(null);
function loadHelper(name) {
if (!helperData[name]) {
const helper = _helpers.default[name];
if (!helper) {
throw Object.assign(new ReferenceError(`Unknown helper ${name}`), {
code: "BABEL_HELPER_UNKNOWN",
helper: name
});
}
const fn = () => {
{
if (!FileClass) {
const fakeFile = {
ast: file(helper.ast()),
path: null
};
(0, _traverse.default)(fakeFile.ast, {
Program: path => (fakeFile.path = path).stop()
});
return fakeFile;
}
}
return new FileClass({
filename: `babel-helper://${name}`
}, {
ast: file(helper.ast()),
code: "[internal Babel helper code]",
inputMap: null
});
};
let metadata = null;
helperData[name] = {
minVersion: helper.minVersion,
build(getDependency, id, localBindings) {
const file = fn();
metadata || (metadata = getHelperMetadata(file));
permuteHelperAST(file, metadata, id, localBindings, getDependency);
return {
nodes: file.ast.program.body,
globals: metadata.globals
};
},
getDependencies() {
metadata || (metadata = getHelperMetadata(fn()));
return Array.from(metadata.dependencies.values());
}
};
}
return helperData[name];
}
function get(name, getDependency, id, localBindings) {
return loadHelper(name).build(getDependency, id, localBindings);
}
function minVersion(name) {
return loadHelper(name).minVersion;
}
function getDependencies(name) {
return loadHelper(name).getDependencies();
}
function ensure(name, newFileClass) {
FileClass || (FileClass = newFileClass);
loadHelper(name);
}
const list = Object.keys(_helpers.default).map(name => name.replace(/^_/, ""));
exports.list = list;
var _default = get;
exports.default = _default;
//# sourceMappingURL=index.js.map
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