Ultralight-SDK/inspector/Models/PropertyPath.js

/*
 * Copyright (C) 2015 Apple Inc. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 *
 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
 * THE POSSIBILITY OF SUCH DAMAGE.
 */

WI.PropertyPath = class PropertyPath
{
    constructor(object, pathComponent, parent, isPrototype)
    {
        console.assert(object instanceof WI.RemoteObject || object === null);
        console.assert(!pathComponent || typeof pathComponent === "string");
        console.assert(!parent || parent instanceof WI.PropertyPath);
        console.assert(!parent || pathComponent.length);

        // We allow property pathes with null objects as end-caps only.
        // Disallow appending to a PropertyPath with null objects.
        if (parent && !parent.object)
            throw new Error("Attempted to append to a PropertyPath with null object.");

        this._object = object;
        this._pathComponent = typeof pathComponent === "string" ? pathComponent : null;
        this._parent = parent || null;
        this._isPrototype = isPrototype || false;
    }

    // Static

    static emptyPropertyPathForScope(object)
    {
        return new WI.PropertyPath(object, WI.PropertyPath.SpecialPathComponent.EmptyPathComponentForScope);
    }

    // Public

    get object() { return this._object; }
    get parent() { return this._parent; }
    get isPrototype() { return this._isPrototype; }

    get pathComponent() { return this._pathComponent; }
    set pathComponent(pathComponent) { this._pathComponent = pathComponent; }

    get rootObject()
    {
        return this._parent ? this._parent.rootObject : this._object;
    }

    get lastNonPrototypeObject()
    {
        if (!this._parent)
            return this._object;

        var p = this._parent;
        while (p) {
            if (!p.isPrototype)
                break;
            if (!p.parent)
                break;
            p = p.parent;
        }

        return p.object;
    }

    get fullPath()
    {
        var components = [];
        for (var p = this; p && p.pathComponent; p = p.parent)
            components.push(p.pathComponent);
        components.reverse();
        return components.join("");
    }

    get reducedPath()
    {
        // The display path for a value should not include __proto__.
        // The path for "foo.__proto__.bar.__proto__.x" is better shown as "foo.bar.x".
        // FIXME: We should keep __proto__ if this property was overridden.
        var components = [];

        var p = this;

        // Include trailing __proto__s.
        for (; p && p.isPrototype; p = p.parent)
            components.push(p.pathComponent);

        // Skip other __proto__s.
        for (; p && p.pathComponent; p = p.parent) {
            if (p.isPrototype)
                continue;
            components.push(p.pathComponent);
        }

        components.reverse();
        return components.join("");
    }

    displayPath(type)
    {
        return type === WI.PropertyPath.Type.Value ? this.reducedPath : this.fullPath;
    }

    isRoot()
    {
        return !this._parent;
    }

    isScope()
    {
        return this._pathComponent === WI.PropertyPath.SpecialPathComponent.EmptyPathComponentForScope;
    }

    isPathComponentImpossible()
    {
        return this._pathComponent && this._pathComponent.startsWith("@");
    }

    isFullPathImpossible()
    {
        if (this.isPathComponentImpossible())
            return true;

        if (this._parent)
            return this._parent.isFullPathImpossible();

        return false;
    }

    appendPropertyName(object, propertyName)
    {
        var isPrototype = propertyName === "__proto__";

        if (this.isScope())
            return new WI.PropertyPath(object, propertyName, this, isPrototype);

        var component = this._canPropertyNameBeDotAccess(propertyName) ? "." + propertyName : "[" + doubleQuotedString(propertyName) + "]";
        return new WI.PropertyPath(object, component, this, isPrototype);
    }

    appendPropertySymbol(object, symbolName)
    {
        var component = WI.PropertyPath.SpecialPathComponent.SymbolPropertyName + (symbolName.length ? "(" + symbolName + ")" : "");
        return new WI.PropertyPath(object, component, this);
    }

    appendInternalPropertyName(object, propertyName)
    {
        var component = WI.PropertyPath.SpecialPathComponent.InternalPropertyName + "[" + propertyName + "]";
        return new WI.PropertyPath(object, component, this);
    }

    appendGetterPropertyName(object, propertyName)
    {
        var component = ".__lookupGetter__(" + doubleQuotedString(propertyName) + ")";
        return new WI.PropertyPath(object, component, this);
    }

    appendSetterPropertyName(object, propertyName)
    {
        var component = ".__lookupSetter__(" + doubleQuotedString(propertyName) + ")";
        return new WI.PropertyPath(object, component, this);
    }

    appendArrayIndex(object, indexString)
    {
        var component = "[" + indexString + "]";
        return new WI.PropertyPath(object, component, this);
    }

    appendMapKey(object)
    {
        var component = WI.PropertyPath.SpecialPathComponent.MapKey;
        return new WI.PropertyPath(object, component, this);
    }

    appendMapValue(object, keyObject)
    {
        console.assert(!keyObject || keyObject instanceof WI.RemoteObject);

        if (keyObject && keyObject.hasValue()) {
            if (keyObject.type === "string") {
                var component = ".get(" + doubleQuotedString(keyObject.description) + ")";
                return new WI.PropertyPath(object, component, this);
            }

            var component = ".get(" + keyObject.description + ")";
            return new WI.PropertyPath(object, component, this);
        }

        var component = WI.PropertyPath.SpecialPathComponent.MapValue;
        return new WI.PropertyPath(object, component, this);
    }

    appendSetIndex(object)
    {
        var component = WI.PropertyPath.SpecialPathComponent.SetIndex;
        return new WI.PropertyPath(object, component, this);
    }

    appendSymbolProperty(object)
    {
        var component = WI.PropertyPath.SpecialPathComponent.SymbolPropertyName;
        return new WI.PropertyPath(object, component, this);
    }

    appendPropertyDescriptor(object, descriptor, type)
    {
        console.assert(descriptor instanceof WI.PropertyDescriptor);

        if (descriptor.isInternalProperty)
            return this.appendInternalPropertyName(object, descriptor.name);
        if (descriptor.symbol)
            return this.appendSymbolProperty(object);

        if (type === WI.PropertyPath.Type.Getter)
            return this.appendGetterPropertyName(object, descriptor.name);
        if (type === WI.PropertyPath.Type.Setter)
            return this.appendSetterPropertyName(object, descriptor.name);

        console.assert(type === WI.PropertyPath.Type.Value);

        if (this._object.subtype === "array" && !isNaN(parseInt(descriptor.name)))
            return this.appendArrayIndex(object, descriptor.name);

        return this.appendPropertyName(object, descriptor.name);
    }

    // Private

    _canPropertyNameBeDotAccess(propertyName)
    {
        return /^(?![0-9])\w+$/.test(propertyName);
    }
};

WI.PropertyPath.SpecialPathComponent = {
    InternalPropertyName: "@internal",
    SymbolPropertyName: "@symbol",
    MapKey: "@mapkey",
    MapValue: "@mapvalue",
    SetIndex: "@setindex",
    EmptyPathComponentForScope: "",
};

WI.PropertyPath.Type = {
    Value: "value",
    Getter: "getter",
    Setter: "setter",
};