proxy-extend/dist/node-esm/proxyExtend.mjs.map

Transparently extend a JS object with additional properties (using ES6 Proxy)

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If so, flatten.\n    if (typeof value === 'object' && value !== null && proxyKey in value) {\n        const unproxied = value[proxyKey];\n        value = unproxied.value;\n        extension = { ...unproxied.extension, ...extension };\n    }\n    \n    let isString = false;\n    let isNumber = false;\n    \n    // Handle primitive values. Because a Proxy always behaves as an object, we cannot really transparently\n    // \"simulate\" a primitive. However, we use sensible equivalents where possible.\n    const valueType = typeof value;\n    let target = value;\n    if (valueType === 'undefined') {\n        throw new TypeError($msg`Cannot construct proxy, given \\`undefined\\``);\n    } else if (value === null) {\n        target = nullObject;\n    } else if (valueType === 'string') {\n        target = new String(value);\n        isString = true;\n    } else if (valueType === 'number') {\n        target = new Number(value);\n        isNumber = true;\n    } else if (valueType === 'bigint') {\n        // TODO: we could use a boxed `BigInt` through `Object()` (e.g. `Object(42n) instanceof BigInt`):\n        // https://2ality.com/2022/02/wrapper-objects.html\n        throw new TypeError($msg`Cannot construct proxy from bigint, given ${value}`);\n    } else if (valueType === 'boolean') {\n        // Note: we could use a boxed `Boolean`, but it would not be very useful because there's not much you can\n        // do with it. Boxed booleans (including `new Boolean(false)`) are treated as truthy in logic operations.\n        throw new TypeError($msg`Cannot construct proxy from boolean, given ${value}`);\n    } else if (valueType === 'symbol') {\n        throw new TypeError($msg`Cannot construct proxy from symbol, given ${value}`);\n    } else if (valueType !== 'object' && valueType !== 'function') {\n        // Note: this shouldn't happen, unless there's a new type of primitive added to JS\n        throw new TypeError($msg`Cannot construct proxy, given value of unknown type ${valueType}`);\n    }\n    \n    // Some methods of built-in types cannot be proxied, i.e. they need to bound directly to the\n    // target. Because they explicitly check the type of `this` (e.g. `Date`), or because they need\n    // to access an internal slot of the target (e.g. `String.toString`).\n    // https://stackoverflow.com/questions/36394479/proxies-on-regexps-and-boxed-primitives\n    // https://stackoverflow.com/questions/47874488/proxy-on-a-date-object\n    // https://stackoverflow.com/questions/43927933/why-is-set-incompatible-with-proxy\n    const usesInternalSlots =\n        target instanceof String\n        || target instanceof Number\n        || target instanceof Boolean\n        || target instanceof Date\n        || target instanceof RegExp\n        || target instanceof Map\n        || target instanceof WeakMap\n        || target instanceof Set\n        || target instanceof WeakSet\n        || target instanceof ArrayBuffer\n        || target instanceof TypedArray;\n    \n    \n    const handler = {\n        has(target, propKey) {\n            if (hasOwnProperty(extension, propKey)) {\n                // Note: use `hasOwnProperty` for the extension, rather than `in`, because we do not want to\n                // consider properties in the prototype chain as being part of the extension.\n                return true;\n            }\n            \n            // Implement `toJSON` for boxed primitives (otherwise `JSON.stringify` will not work properly).\n            if (propKey === 'toJSON' && (isString || isNumber)) { return true; }\n            \n            if (propKey === nodeInspectCustom) { return true; }\n            if (propKey === proxyKey) { return true; }\n            \n            return Reflect.has(target, propKey);\n        },\n        \n        get(target, propKey, receiver) {\n            // Backdoor to get the internal proxied data (value and extension).\n            // Note: use `value` here, not `target` (target is just an internal representation).\n            if (propKey === proxyKey) { return { value, extension }; }\n            \n            let targetProp = undefined;\n            if (hasOwnProperty(extension, propKey)) {\n                targetProp = extension[propKey];\n            } else if (propKey in target) {\n                targetProp = target[propKey];\n                \n                // Note: any getter properties will receive the `target`, rather than the proxy as their `this`\n                // value. Thus, getters will not have access to the extension. If you really need this behavior,\n                // you can use the following. But it's not recommended, due to the impact on performance.\n                /*\n                if (hasOwnProperty(target, propKey)) {\n                    const descriptor = Object.getOwnPropertyDescriptor(target, propKey);\n                    if (typeof descriptor.get === 'function') {\n                        targetProp = descriptor.get.call(receiver);\n                    }\n                }\n                */\n            } else {\n                // Fallback: property is present in neither the target nor the extension\n                \n                // Implement `toJSON` for boxed primitives (otherwise `JSON.stringify` will not work properly).\n                if (propKey === 'toJSON') {\n                    if (isString) {\n                        targetProp = target.toString.bind(target);\n                    } else if (isNumber) {\n                        targetProp = target.valueOf.bind(target);\n                    }\n                }\n                \n              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=== 'number') {\n        return true;\n    } else {\n        return false;\n    }\n};\n\n// Whether the given value is a proxy\nexport const isProxy = value => {\n    return typeof value === 'object' && value !== null && proxyKey in value;\n};\n\n// Unwrap the given proxy to access its internal data\nexport const unwrapProxy = proxy => {\n    if (!isProxy(proxy)) {\n        throw new TypeError($msg`Cannot unwrap input, expected a proxy, received: ${proxy}`);\n    }\n    \n    return proxy[proxyKey];\n};\n\n// Add some properties to `extend` as shorthand\nextend.is = isProxy;\nextend.unwrap = unwrapProxy;\n\n// Make formatting of proxies a little nicer\nexport const registerProxyFormatter = () => {\n    if (typeof require === 'function') {\n        const util = require('util');\n        \n        if (util.inspect && util.inspect.replDefaults) {\n            util.inspect.replDefaults.showProxy = false;\n        }\n    }\n    \n    // https://stackoverflow.com/questions/55733647/chrome-devtools-formatter-for-javascript-proxy\n    if (typeof window === 'object' && window !== null) {\n        if (!Array.isArray(window.devtoolsFormatters)) {\n            window.devtoolsFormatters = [];\n        }\n        \n        window.devtoolsFormatters.push({\n            header(value) {\n                if (!isProxy(value)) {\n                    return null;\n                }\n                \n                return ['object', { object: value[proxyKey].value }];\n            },\n        });\n    }\n};\n\nexport default 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