node_modules/@babel/plugin-transform-classes/lib/transformClass.js

"use strict";

Object.defineProperty(exports, "__esModule", {
  value: true
});
exports.default = transformClass;

var _helperFunctionName = require("@babel/helper-function-name");

var _helperReplaceSupers = require("@babel/helper-replace-supers");

var _helperEnvironmentVisitor = require("@babel/helper-environment-visitor");

var _helperOptimiseCallExpression = require("@babel/helper-optimise-call-expression");

var _core = require("@babel/core");

var _helperAnnotateAsPure = require("@babel/helper-annotate-as-pure");

var _inlineCreateSuperHelpers = require("./inline-createSuper-helpers");

function buildConstructor(classRef, constructorBody, node) {
  const func = _core.types.functionDeclaration(_core.types.cloneNode(classRef), [], constructorBody);

  _core.types.inherits(func, node);

  return func;
}

function transformClass(path, file, builtinClasses, isLoose, assumptions) {
  const classState = {
    parent: undefined,
    scope: undefined,
    node: undefined,
    path: undefined,
    file: undefined,
    classId: undefined,
    classRef: undefined,
    superFnId: undefined,
    superName: undefined,
    superReturns: [],
    isDerived: false,
    extendsNative: false,
    construct: undefined,
    constructorBody: undefined,
    userConstructor: undefined,
    userConstructorPath: undefined,
    hasConstructor: false,
    staticPropBody: [],
    body: [],
    superThises: [],
    pushedConstructor: false,
    pushedInherits: false,
    pushedCreateClass: false,
    protoAlias: null,
    isLoose: false,
    dynamicKeys: new Map(),
    methods: {
      instance: {
        hasComputed: false,
        list: [],
        map: new Map()
      },
      static: {
        hasComputed: false,
        list: [],
        map: new Map()
      }
    }
  };

  const setState = newState => {
    Object.assign(classState, newState);
  };

  const findThisesVisitor = _core.traverse.visitors.merge([_helperEnvironmentVisitor.default, {
    ThisExpression(path) {
      classState.superThises.push(path);
    }

  }]);

  function createClassHelper(args) {
    return _core.types.callExpression(classState.file.addHelper("createClass"), args);
  }

  function maybeCreateConstructor() {
    let hasConstructor = false;
    const paths = classState.path.get("body.body");

    for (const path of paths) {
      hasConstructor = path.equals("kind", "constructor");
      if (hasConstructor) break;
    }

    if (hasConstructor) return;
    let params, body;

    if (classState.isDerived) {
      const constructor = _core.template.expression.ast`
        (function () {
          super(...arguments);
        })
      `;
      params = constructor.params;
      body = constructor.body;
    } else {
      params = [];
      body = _core.types.blockStatement([]);
    }

    classState.path.get("body").unshiftContainer("body", _core.types.classMethod("constructor", _core.types.identifier("constructor"), params, body));
  }

  function buildBody() {
    maybeCreateConstructor();
    pushBody();
    verifyConstructor();

    if (classState.userConstructor) {
      const {
        constructorBody,
        userConstructor,
        construct
      } = classState;
      constructorBody.body.push(...userConstructor.body.body);

      _core.types.inherits(construct, userConstructor);

      _core.types.inherits(constructorBody, userConstructor.body);
    }

    pushDescriptors();
  }

  function pushBody() {
    const classBodyPaths = classState.path.get("body.body");

    for (const path of classBodyPaths) {
      const node = path.node;

      if (path.isClassProperty()) {
        throw path.buildCodeFrameError("Missing class properties transform.");
      }

      if (node.decorators) {
        throw path.buildCodeFrameError("Method has decorators, put the decorator plugin before the classes one.");
      }

      if (_core.types.isClassMethod(node)) {
        const isConstructor = node.kind === "constructor";
        const replaceSupers = new _helperReplaceSupers.default({
          methodPath: path,
          objectRef: classState.classRef,
          superRef: classState.superName,
          constantSuper: assumptions.constantSuper,
          file: classState.file,
          refToPreserve: classState.classRef
        });
        replaceSupers.replace();
        const superReturns = [];
        path.traverse(_core.traverse.visitors.merge([_helperEnvironmentVisitor.default, {
          ReturnStatement(path) {
            if (!path.getFunctionParent().isArrowFunctionExpression()) {
              superReturns.push(path);
            }
          }

        }]));

        if (isConstructor) {
          pushConstructor(superReturns, node, path);
        } else {
          pushMethod(node, path);
        }
      }
    }
  }

  function pushDescriptors() {
    pushInheritsToBody();
    const {
      body
    } = classState;
    const props = {
      instance: null,
      static: null
    };

    for (const placement of ["static", "instance"]) {
      if (classState.methods[placement].list.length) {
        props[placement] = classState.methods[placement].list.map(desc => {
          const obj = _core.types.objectExpression([_core.types.objectProperty(_core.types.identifier("key"), desc.key)]);

          for (const kind of ["get", "set", "value"]) {
            if (desc[kind] != null) {
              obj.properties.push(_core.types.objectProperty(_core.types.identifier(kind), desc[kind]));
            }
          }

          return obj;
        });
      }
    }

    if (props.instance || props.static) {
      let args = [_core.types.cloneNode(classState.classRef), props.instance ? _core.types.arrayExpression(props.instance) : _core.types.nullLiteral(), props.static ? _core.types.arrayExpression(props.static) : _core.types.nullLiteral()];
      let lastNonNullIndex = 0;

      for (let i = 0; i < args.length; i++) {
        if (!_core.types.isNullLiteral(args[i])) lastNonNullIndex = i;
      }

      args = args.slice(0, lastNonNullIndex + 1);
      body.push(_core.types.expressionStatement(createClassHelper(args)));
      classState.pushedCreateClass = true;
    }
  }

  function wrapSuperCall(bareSuper, superRef, thisRef, body) {
    const bareSuperNode = bareSuper.node;
    let call;

    if (assumptions.superIsCallableConstructor) {
      bareSuperNode.arguments.unshift(_core.types.thisExpression());

      if (bareSuperNode.arguments.length === 2 && _core.types.isSpreadElement(bareSuperNode.arguments[1]) && _core.types.isIdentifier(bareSuperNode.arguments[1].argument, {
        name: "arguments"
      })) {
        bareSuperNode.arguments[1] = bareSuperNode.arguments[1].argument;
        bareSuperNode.callee = _core.types.memberExpression(_core.types.cloneNode(superRef), _core.types.identifier("apply"));
      } else {
        bareSuperNode.callee = _core.types.memberExpression(_core.types.cloneNode(superRef), _core.types.identifier("call"));
      }

      call = _core.types.logicalExpression("||", bareSuperNode, _core.types.thisExpression());
    } else {
      call = (0, _helperOptimiseCallExpression.default)(_core.types.cloneNode(classState.superFnId), _core.types.thisExpression(), bareSuperNode.arguments, false);
    }

    if (bareSuper.parentPath.isExpressionStatement() && bareSuper.parentPath.container === body.node.body && body.node.body.length - 1 === bareSuper.parentPath.key) {
      if (classState.superThises.length) {
        call = _core.types.assignmentExpression("=", thisRef(), call);
      }

      bareSuper.parentPath.replaceWith(_core.types.returnStatement(call));
    } else {
      bareSuper.replaceWith(_core.types.assignmentExpression("=", thisRef(), call));
    }
  }

  function verifyConstructor() {
    if (!classState.isDerived) return;
    const path = classState.userConstructorPath;
    const body = path.get("body");
    path.traverse(findThisesVisitor);

    let thisRef = function () {
      const ref = path.scope.generateDeclaredUidIdentifier("this");

      thisRef = () => _core.types.cloneNode(ref);

      return ref;
    };

    for (const thisPath of classState.superThises) {
      const {
        node,
        parentPath
      } = thisPath;

      if (parentPath.isMemberExpression({
        object: node
      })) {
        thisPath.replaceWith(thisRef());
        continue;
      }

      thisPath.replaceWith(_core.types.callExpression(classState.file.addHelper("assertThisInitialized"), [thisRef()]));
    }

    const bareSupers = new Set();
    path.traverse(_core.traverse.visitors.merge([_helperEnvironmentVisitor.default, {
      Super(path) {
        const {
          node,
          parentPath
        } = path;

        if (parentPath.isCallExpression({
          callee: node
        })) {
          bareSupers.add(parentPath);
        }
      }

    }]));
    let guaranteedSuperBeforeFinish = !!bareSupers.size;

    for (const bareSuper of bareSupers) {
      wrapSuperCall(bareSuper, classState.superName, thisRef, body);

      if (guaranteedSuperBeforeFinish) {
        bareSuper.find(function (parentPath) {
          if (parentPath === path) {
            return true;
          }

          if (parentPath.isLoop() || parentPath.isConditional() || parentPath.isArrowFunctionExpression()) {
            guaranteedSuperBeforeFinish = false;
            return true;
          }
        });
      }
    }

    let wrapReturn;

    if (classState.isLoose) {
      wrapReturn = returnArg => {
        const thisExpr = _core.types.callExpression(classState.file.addHelper("assertThisInitialized"), [thisRef()]);

        return returnArg ? _core.types.logicalExpression("||", returnArg, thisExpr) : thisExpr;
      };
    } else {
      wrapReturn = returnArg => _core.types.callExpression(classState.file.addHelper("possibleConstructorReturn"), [thisRef()].concat(returnArg || []));
    }

    const bodyPaths = body.get("body");

    if (!bodyPaths.length || !bodyPaths.pop().isReturnStatement()) {
      body.pushContainer("body", _core.types.returnStatement(guaranteedSuperBeforeFinish ? thisRef() : wrapReturn()));
    }

    for (const returnPath of classState.superReturns) {
      returnPath.get("argument").replaceWith(wrapReturn(returnPath.node.argument));
    }
  }

  function pushMethod(node, path) {
    const scope = path ? path.scope : classState.scope;

    if (node.kind === "method") {
      if (processMethod(node, scope)) return;
    }

    const placement = node.static ? "static" : "instance";
    const methods = classState.methods[placement];
    const descKey = node.kind === "method" ? "value" : node.kind;
    const key = _core.types.isNumericLiteral(node.key) || _core.types.isBigIntLiteral(node.key) ? _core.types.stringLiteral(String(node.key.value)) : _core.types.toComputedKey(node);

    let fn = _core.types.toExpression(node);

    if (_core.types.isStringLiteral(key)) {
      if (node.kind === "method") {
        fn = (0, _helperFunctionName.default)({
          id: key,
          node: node,
          scope
        });
      }
    } else {
      methods.hasComputed = true;
    }

    let descriptor;

    if (!methods.hasComputed && methods.map.has(key.value)) {
      descriptor = methods.map.get(key.value);
      descriptor[descKey] = fn;

      if (descKey === "value") {
        descriptor.get = null;
        descriptor.set = null;
      } else {
        descriptor.value = null;
      }
    } else {
      descriptor = {
        key: key,
        [descKey]: fn
      };
      methods.list.push(descriptor);

      if (!methods.hasComputed) {
        methods.map.set(key.value, descriptor);
      }
    }
  }

  function processMethod(node, scope) {
    if (assumptions.setClassMethods && !node.decorators) {
      let {
        classRef
      } = classState;

      if (!node.static) {
        insertProtoAliasOnce();
        classRef = classState.protoAlias;
      }

      const methodName = _core.types.memberExpression(_core.types.cloneNode(classRef), node.key, node.computed || _core.types.isLiteral(node.key));

      let func = _core.types.functionExpression(null, node.params, node.body, node.generator, node.async);

      _core.types.inherits(func, node);

      const key = _core.types.toComputedKey(node, node.key);

      if (_core.types.isStringLiteral(key)) {
        func = (0, _helperFunctionName.default)({
          node: func,
          id: key,
          scope
        });
      }

      const expr = _core.types.expressionStatement(_core.types.assignmentExpression("=", methodName, func));

      _core.types.inheritsComments(expr, node);

      classState.body.push(expr);
      return true;
    }

    return false;
  }

  function insertProtoAliasOnce() {
    if (classState.protoAlias === null) {
      setState({
        protoAlias: classState.scope.generateUidIdentifier("proto")
      });

      const classProto = _core.types.memberExpression(classState.classRef, _core.types.identifier("prototype"));

      const protoDeclaration = _core.types.variableDeclaration("var", [_core.types.variableDeclarator(classState.protoAlias, classProto)]);

      classState.body.push(protoDeclaration);
    }
  }

  function pushConstructor(superReturns, method, path) {
    setState({
      userConstructorPath: path,
      userConstructor: method,
      hasConstructor: true,
      superReturns
    });
    const {
      construct
    } = classState;

    _core.types.inheritsComments(construct, method);

    construct.params = method.params;

    _core.types.inherits(construct.body, method.body);

    construct.body.directives = method.body.directives;
    pushConstructorToBody();
  }

  function pushConstructorToBody() {
    if (classState.pushedConstructor) return;
    classState.pushedConstructor = true;

    if (classState.hasInstanceDescriptors || classState.hasStaticDescriptors) {
      pushDescriptors();
    }

    classState.body.push(classState.construct);
    pushInheritsToBody();
  }

  function pushInheritsToBody() {
    if (!classState.isDerived || classState.pushedInherits) return;
    const superFnId = path.scope.generateUidIdentifier("super");
    setState({
      pushedInherits: true,
      superFnId
    });

    if (!assumptions.superIsCallableConstructor) {
      classState.body.unshift(_core.types.variableDeclaration("var", [_core.types.variableDeclarator(superFnId, _core.types.callExpression((0, _inlineCreateSuperHelpers.default)(classState.file), [_core.types.cloneNode(classState.classRef)]))]));
    }

    classState.body.unshift(_core.types.expressionStatement(_core.types.callExpression(classState.file.addHelper(classState.isLoose ? "inheritsLoose" : "inherits"), [_core.types.cloneNode(classState.classRef), _core.types.cloneNode(classState.superName)])));
  }

  function extractDynamicKeys() {
    const {
      dynamicKeys,
      node,
      scope
    } = classState;

    for (const elem of node.body.body) {
      if (!_core.types.isClassMethod(elem) || !elem.computed) continue;
      if (scope.isPure(elem.key, true)) continue;
      const id = scope.generateUidIdentifierBasedOnNode(elem.key);
      dynamicKeys.set(id.name, elem.key);
      elem.key = id;
    }
  }

  function setupClosureParamsArgs() {
    const {
      superName,
      dynamicKeys
    } = classState;
    const closureParams = [];
    const closureArgs = [];

    if (classState.isDerived) {
      let arg = _core.types.cloneNode(superName);

      if (classState.extendsNative) {
        arg = _core.types.callExpression(classState.file.addHelper("wrapNativeSuper"), [arg]);
        (0, _helperAnnotateAsPure.default)(arg);
      }

      const param = classState.scope.generateUidIdentifierBasedOnNode(superName);
      closureParams.push(param);
      closureArgs.push(arg);
      setState({
        superName: _core.types.cloneNode(param)
      });
    }

    for (const [name, value] of dynamicKeys) {
      closureParams.push(_core.types.identifier(name));
      closureArgs.push(value);
    }

    return {
      closureParams,
      closureArgs
    };
  }

  function classTransformer(path, file, builtinClasses, isLoose) {
    setState({
      parent: path.parent,
      scope: path.scope,
      node: path.node,
      path,
      file,
      isLoose
    });
    setState({
      classId: classState.node.id,
      classRef: classState.node.id ? _core.types.identifier(classState.node.id.name) : classState.scope.generateUidIdentifier("class"),
      superName: classState.node.superClass,
      isDerived: !!classState.node.superClass,
      constructorBody: _core.types.blockStatement([])
    });
    setState({
      extendsNative: classState.isDerived && builtinClasses.has(classState.superName.name) && !classState.scope.hasBinding(classState.superName.name, true)
    });
    const {
      classRef,
      node,
      constructorBody
    } = classState;
    setState({
      construct: buildConstructor(classRef, constructorBody, node)
    });
    extractDynamicKeys();
    const {
      body
    } = classState;
    const {
      closureParams,
      closureArgs
    } = setupClosureParamsArgs();
    buildBody();

    if (!assumptions.noClassCalls) {
      constructorBody.body.unshift(_core.types.expressionStatement(_core.types.callExpression(classState.file.addHelper("classCallCheck"), [_core.types.thisExpression(), _core.types.cloneNode(classState.classRef)])));
    }

    body.push(...classState.staticPropBody.map(fn => fn(_core.types.cloneNode(classState.classRef))));
    const isStrict = path.isInStrictMode();
    let constructorOnly = classState.classId && body.length === 1;

    if (constructorOnly && !isStrict) {
      for (const param of classState.construct.params) {
        if (!_core.types.isIdentifier(param)) {
          constructorOnly = false;
          break;
        }
      }
    }

    const directives = constructorOnly ? body[0].body.directives : [];

    if (!isStrict) {
      directives.push(_core.types.directive(_core.types.directiveLiteral("use strict")));
    }

    if (constructorOnly) {
      const expr = _core.types.toExpression(body[0]);

      return classState.isLoose ? expr : createClassHelper([expr]);
    }

    let returnArg = _core.types.cloneNode(classState.classRef);

    if (!classState.pushedCreateClass && !classState.isLoose) {
      returnArg = createClassHelper([returnArg]);
    }

    body.push(_core.types.returnStatement(returnArg));

    const container = _core.types.arrowFunctionExpression(closureParams, _core.types.blockStatement(body, directives));

    return _core.types.callExpression(container, closureArgs);
  }

  return classTransformer(path, file, builtinClasses, isLoose);
}