380 lines
12 KiB
JavaScript

import hoistVariables from "@babel/helper-hoist-variables";
import { template, types as t } from "@babel/core";
const buildTemplate = template(`
SYSTEM_REGISTER(MODULE_NAME, SOURCES, function (EXPORT_IDENTIFIER, CONTEXT_IDENTIFIER) {
"use strict";
BEFORE_BODY;
return {
setters: SETTERS,
execute: function () {
BODY;
}
};
});
`);
const buildExportAll = template(`
for (var KEY in TARGET) {
if (KEY !== "default" && KEY !== "__esModule") EXPORT_OBJ[KEY] = TARGET[KEY];
}
`);
const TYPE_IMPORT = "Import";
export default function(api, options) {
const { systemGlobal = "System" } = options;
const IGNORE_REASSIGNMENT_SYMBOL = Symbol();
const reassignmentVisitor = {
"AssignmentExpression|UpdateExpression"(path) {
if (path.node[IGNORE_REASSIGNMENT_SYMBOL]) return;
path.node[IGNORE_REASSIGNMENT_SYMBOL] = true;
const arg = path.get(path.isAssignmentExpression() ? "left" : "argument");
if (!arg.isIdentifier()) return;
const name = arg.node.name;
// redeclared in this scope
if (this.scope.getBinding(name) !== path.scope.getBinding(name)) return;
const exportedNames = this.exports[name];
if (!exportedNames) return;
let node = path.node;
// if it is a non-prefix update expression (x++ etc)
// then we must replace with the expression (_export('x', x + 1), x++)
// in order to ensure the same update expression value
let isPostUpdateExpression = path.isUpdateExpression() && !node.prefix;
if (isPostUpdateExpression) {
if (node.operator === "++") {
node = t.binaryExpression("+", node.argument, t.numericLiteral(1));
} else if (node.operator === "--") {
node = t.binaryExpression("-", node.argument, t.numericLiteral(1));
} else {
isPostUpdateExpression = false;
}
}
for (const exportedName of exportedNames) {
node = this.buildCall(exportedName, node).expression;
}
if (isPostUpdateExpression) {
node = t.sequenceExpression([node, path.node]);
}
path.replaceWith(node);
},
};
return {
visitor: {
CallExpression(path, state) {
if (path.node.callee.type === TYPE_IMPORT) {
const contextIdent = state.contextIdent;
path.replaceWith(
t.callExpression(
t.memberExpression(contextIdent, t.identifier("import")),
path.node.arguments,
),
);
}
},
ReferencedIdentifier(path, state) {
if (
path.node.name == "__moduleName" &&
!path.scope.hasBinding("__moduleName")
) {
path.replaceWith(
t.memberExpression(state.contextIdent, t.identifier("id")),
);
}
},
Program: {
enter(path, state) {
state.contextIdent = path.scope.generateUidIdentifier("context");
},
exit(path, state) {
const exportIdent = path.scope.generateUidIdentifier("export");
const contextIdent = state.contextIdent;
const exportNames = Object.create(null);
const modules = [];
let beforeBody = [];
const setters = [];
const sources = [];
const variableIds = [];
const removedPaths = [];
function addExportName(key, val) {
exportNames[key] = exportNames[key] || [];
exportNames[key].push(val);
}
function pushModule(source, key, specifiers) {
let module;
modules.forEach(function(m) {
if (m.key === source) {
module = m;
}
});
if (!module) {
modules.push(
(module = { key: source, imports: [], exports: [] }),
);
}
module[key] = module[key].concat(specifiers);
}
function buildExportCall(name, val) {
return t.expressionStatement(
t.callExpression(exportIdent, [t.stringLiteral(name), val]),
);
}
const body: Array<Object> = path.get("body");
let canHoist = true;
for (let path of body) {
if (path.isExportDeclaration()) path = path.get("declaration");
if (path.isVariableDeclaration() && path.node.kind !== "var") {
canHoist = false;
break;
}
}
for (const path of body) {
if (canHoist && path.isFunctionDeclaration()) {
beforeBody.push(path.node);
removedPaths.push(path);
} else if (path.isImportDeclaration()) {
const source = path.node.source.value;
pushModule(source, "imports", path.node.specifiers);
for (const name in path.getBindingIdentifiers()) {
path.scope.removeBinding(name);
variableIds.push(t.identifier(name));
}
path.remove();
} else if (path.isExportAllDeclaration()) {
pushModule(path.node.source.value, "exports", path.node);
path.remove();
} else if (path.isExportDefaultDeclaration()) {
const declar = path.get("declaration");
if (
declar.isClassDeclaration() ||
declar.isFunctionDeclaration()
) {
const id = declar.node.id;
const nodes = [];
if (id) {
nodes.push(declar.node);
nodes.push(buildExportCall("default", id));
addExportName(id.name, "default");
} else {
nodes.push(
buildExportCall("default", t.toExpression(declar.node)),
);
}
if (!canHoist || declar.isClassDeclaration()) {
path.replaceWithMultiple(nodes);
} else {
beforeBody = beforeBody.concat(nodes);
removedPaths.push(path);
}
} else {
path.replaceWith(buildExportCall("default", declar.node));
}
} else if (path.isExportNamedDeclaration()) {
const declar = path.get("declaration");
if (declar.node) {
path.replaceWith(declar);
const nodes = [];
let bindingIdentifiers;
if (path.isFunction()) {
const node = declar.node;
const name = node.id.name;
if (canHoist) {
addExportName(name, name);
beforeBody.push(node);
beforeBody.push(buildExportCall(name, node.id));
removedPaths.push(path);
} else {
bindingIdentifiers = { [name]: node.id };
}
} else {
bindingIdentifiers = declar.getBindingIdentifiers();
}
for (const name in bindingIdentifiers) {
addExportName(name, name);
nodes.push(buildExportCall(name, t.identifier(name)));
}
path.insertAfter(nodes);
} else {
const specifiers = path.node.specifiers;
if (specifiers && specifiers.length) {
if (path.node.source) {
pushModule(path.node.source.value, "exports", specifiers);
path.remove();
} else {
const nodes = [];
for (const specifier of specifiers) {
nodes.push(
buildExportCall(
specifier.exported.name,
specifier.local,
),
);
addExportName(
specifier.local.name,
specifier.exported.name,
);
}
path.replaceWithMultiple(nodes);
}
}
}
}
}
modules.forEach(function(specifiers) {
const setterBody = [];
const target = path.scope.generateUidIdentifier(specifiers.key);
for (let specifier of specifiers.imports) {
if (t.isImportNamespaceSpecifier(specifier)) {
setterBody.push(
t.expressionStatement(
t.assignmentExpression("=", specifier.local, target),
),
);
} else if (t.isImportDefaultSpecifier(specifier)) {
specifier = t.importSpecifier(
specifier.local,
t.identifier("default"),
);
}
if (t.isImportSpecifier(specifier)) {
setterBody.push(
t.expressionStatement(
t.assignmentExpression(
"=",
specifier.local,
t.memberExpression(target, specifier.imported),
),
),
);
}
}
if (specifiers.exports.length) {
const exportObjRef = path.scope.generateUidIdentifier(
"exportObj",
);
setterBody.push(
t.variableDeclaration("var", [
t.variableDeclarator(exportObjRef, t.objectExpression([])),
]),
);
for (const node of specifiers.exports) {
if (t.isExportAllDeclaration(node)) {
setterBody.push(
buildExportAll({
KEY: path.scope.generateUidIdentifier("key"),
EXPORT_OBJ: exportObjRef,
TARGET: target,
}),
);
} else if (t.isExportSpecifier(node)) {
setterBody.push(
t.expressionStatement(
t.assignmentExpression(
"=",
t.memberExpression(exportObjRef, node.exported),
t.memberExpression(target, node.local),
),
),
);
} else {
// todo
}
}
setterBody.push(
t.expressionStatement(
t.callExpression(exportIdent, [exportObjRef]),
),
);
}
sources.push(t.stringLiteral(specifiers.key));
setters.push(
t.functionExpression(
null,
[target],
t.blockStatement(setterBody),
),
);
});
let moduleName = this.getModuleName();
if (moduleName) moduleName = t.stringLiteral(moduleName);
if (canHoist) {
hoistVariables(path, id => variableIds.push(id));
}
if (variableIds.length) {
beforeBody.unshift(
t.variableDeclaration(
"var",
variableIds.map(id => t.variableDeclarator(id)),
),
);
}
path.traverse(reassignmentVisitor, {
exports: exportNames,
buildCall: buildExportCall,
scope: path.scope,
});
for (const path of removedPaths) {
path.remove();
}
path.node.body = [
buildTemplate({
SYSTEM_REGISTER: t.memberExpression(
t.identifier(systemGlobal),
t.identifier("register"),
),
BEFORE_BODY: beforeBody,
MODULE_NAME: moduleName,
SETTERS: t.arrayExpression(setters),
SOURCES: t.arrayExpression(sources),
BODY: path.node.body,
EXPORT_IDENTIFIER: exportIdent,
CONTEXT_IDENTIFIER: contextIdent,
}),
];
},
},
},
};
}