{"id":3672,"date":"2026-11-01T09:34:41","date_gmt":"2026-11-01T00:34:41","guid":{"rendered":"https:\/\/qol-kk.com\/wp2\/?p=3672"},"modified":"2026-11-01T09:34:41","modified_gmt":"2026-11-01T00:34:41","slug":"20261024-00mvllzw","status":"publish","type":"post","link":"https:\/\/qol-kk.com\/wp2\/blog\/2026\/11\/01\/20261024-00mvllzw\/","title":{"rendered":"core-js\u3068babel\/preset-env\u3067\u7406\u89e3\u3059\u308b\u30c8\u30e9\u30f3\u30b9\u30d1\u30a4\u30eb\u3068\u30dd\u30ea\u30d5\u30a3\u30eb"},"content":{"rendered":"<h2>\u6982\u8981<\/h2>\n<p>\u30e2\u30c0\u30f3\u306a\u30d5\u30ed\u30f3\u30c8\u30a8\u30f3\u30c9\u958b\u767a\u3067\u306f\u3001\u6700\u65b0\u306eJavaScript\u69cb\u6587\u3092\u66f8\u3044\u3066\u3082\u53e4\u3044\u30d6\u30e9\u30a6\u30b6\u3067\u52d5\u304f\u3002\u3053\u308c\u3092\u652f\u3048\u3066\u3044\u308b\u306e\u304cBabel\u3060\u3002\u3057\u304b\u3057\u300cBabel\u3092\u4f7f\u3048\u3070\u5168\u90e8\u3088\u3057\u306a\u306b\u5909\u63db\u3057\u3066\u304f\u308c\u308b\u300d\u3068\u7406\u89e3\u3057\u3066\u3044\u308b\u3068\u3001<code>async<\/code>\u306f\u52d5\u304f\u306e\u306b<code>Array.prototype.flat<\/code>\u304c<code>undefined is not a function<\/code>\u3067\u843d\u3061\u308b\u3001\u3068\u3044\u3063\u305f\u4e8b\u6545\u306b\u906d\u3046\u3002<\/p>\n<p>\u3053\u306e\u8a18\u4e8b\u3067\u306f\u3001<strong>\u30c8\u30e9\u30f3\u30b9\u30d1\u30a4\u30eb\uff08transpile\uff09<\/strong> \u3068 <strong>\u30dd\u30ea\u30d5\u30a3\u30eb\uff08polyfill\uff09<\/strong> \u3068\u3044\u30462\u3064\u306e\u5225\u7269\u3092\u5207\u308a\u5206\u3051\u305f\u3046\u3048\u3067\u3001<code>@babel\/preset-env<\/code> \u3068 <code>core-js<\/code> \u304c\u305d\u308c\u305e\u308c\u4f55\u3092\u62c5\u5f53\u3057\u3066\u3044\u308b\u306e\u304b\u3092\u8003\u5bdf\u3059\u308b\u3002\u4e21\u8005\u306e\u5883\u754c\u3092\u7406\u89e3\u3057\u3066\u304a\u304f\u3068\u3001\u30d0\u30f3\u30c9\u30eb\u30b5\u30a4\u30ba\u306e\u80a5\u5927\u3084\u300c\u672c\u756a\u3060\u3051\u843d\u3061\u308b\u300d\u7cfb\u306e\u30d0\u30b0\u306b\u5bfe\u3057\u3066\u7b4b\u306e\u3044\u3044\u5224\u65ad\u304c\u3067\u304d\u308b\u3002<\/p>\n<h2>\u30c8\u30e9\u30f3\u30b9\u30d1\u30a4\u30eb\u3068\u30dd\u30ea\u30d5\u30a3\u30eb\u306f\u5225\u306e\u554f\u984c\u3092\u89e3\u3044\u3066\u3044\u308b<\/h2>\n<h3>\u30c8\u30e9\u30f3\u30b9\u30d1\u30a4\u30eb = \u69cb\u6587\u306e\u66f8\u304d\u63db\u3048<\/h3>\n<p>\u30c8\u30e9\u30f3\u30b9\u30d1\u30a4\u30eb\u306f\u3001\u65b0\u3057\u3044<strong>\u69cb\u6587\uff08syntax\uff09<\/strong> \u3092\u53e4\u3044\u69cb\u6587\u306b\u66f8\u304d\u63db\u3048\u308b\u51e6\u7406\u3060\u3002\u69cb\u6587\u3068\u306f\u3001JavaScript\u306e\u6587\u6cd5\u305d\u306e\u3082\u306e\u3092\u6307\u3059\u3002<\/p>\n<pre class=\"lang:default decode:true\">\/\/ Before\nconst add = (a, b) =&gt; a + b;\nclass User {}\nconst run = async () =&gt; { await task(); };\n\n\/\/ After\uff08\u30a4\u30e1\u30fc\u30b8\uff09\nvar add = function (a, b) { return a + b; };\nfunction User() {}\n\/\/ async \u306f\u30b9\u30c6\u30fc\u30c8\u30de\u30b7\u30f3\u3078\u5c55\u958b<\/pre>\n<p>\u30a2\u30ed\u30fc\u95a2\u6570\u30fb\u30af\u30e9\u30b9\u69cb\u6587\u30fb<code>async\/await<\/code>\u30fb\u30b9\u30d7\u30ec\u30c3\u30c9\u69cb\u6587\u30fb\u30aa\u30d7\u30b7\u30e7\u30ca\u30eb\u30c1\u30a7\u30a4\u30cb\u30f3\u30b0 <code>?.<\/code>\u3002\u3053\u308c\u3089\u306f\u300c\u66f8\u304d\u65b9\u300d\u304c\u65b0\u3057\u3044\u3060\u3051\u3067\u3001\u3084\u3063\u3066\u3044\u308b\u3053\u3068\u81ea\u4f53\u306f\u53e4\u3044JavaScript\u3067\u3082\u8868\u73fe\u3067\u304d\u308b\u3002\u3060\u304b\u3089Babel\u306f\u30bd\u30fc\u30b9\u30b3\u30fc\u30c9\u3092\u9759\u7684\u306b\u89e3\u6790\u3057\u3001\u7b49\u4fa1\u306a\u53e4\u3044\u66f8\u304d\u65b9\u3078\u30bd\u30fc\u30b9\u30b3\u30fc\u30c9\u30ec\u30d9\u30eb\u3067\u7f6e\u304d\u63db\u3048\u3089\u308c\u308b\u3002\u5b9f\u884c\u74b0\u5883\u306b\u4f55\u3082\u8db3\u3059\u5fc5\u8981\u304c\u306a\u3044\u3002\u3053\u308c\u304cBabel\u672c\u4f53\u306e\u4ed5\u4e8b\u3060\u3002<\/p>\n<h3>\u30dd\u30ea\u30d5\u30a3\u30eb = API\u306e\u5f8c\u4ed8\u3051\u5b9f\u88c5<\/h3>\n<p>\u4e00\u65b9\u3001\u4ee5\u4e0b\u306f\u69cb\u6587\u3067\u306f\u306a\u304f<strong>\u5b9f\u884c\u6642\u306e\u30aa\u30d6\u30b8\u30a7\u30af\u30c8\u30fb\u30e1\u30bd\u30c3\u30c9<\/strong>\u3060\u3002<\/p>\n<pre class=\"lang:default decode:true\">[1, 2, 3].flat();            \/\/ Array.prototype.flat\n[1, 2, 3].at(-1);            \/\/ Array.prototype.at\nObject.fromEntries(entries); \/\/ Object.fromEntries\n\"a,b\".replaceAll(\",\", \"-\");  \/\/ String.prototype.replaceAll\nnew Map(); new Set();        \/\/ Map \/ Set<\/pre>\n<p><code>flat<\/code> \u304c\u5b58\u5728\u3057\u306a\u3044\u30d6\u30e9\u30a6\u30b6\u306b\u5bfe\u3057\u3066\u300c<code>flat<\/code> \u3068\u3044\u3046\u66f8\u304d\u65b9\u3092\u5225\u306e\u66f8\u304d\u65b9\u306b\u5909\u63db\u3059\u308b\u300d\u3053\u3068\u306f\u3067\u304d\u306a\u3044\u3002<code>flat<\/code> \u306f\u6587\u6cd5\u3067\u306f\u306a\u304f\u3001\u5b9f\u884c\u6642\u306b <code>Array.prototype<\/code> \u3078\u751f\u3048\u3066\u3044\u308b\u3079\u304d\u30e1\u30bd\u30c3\u30c9\u3060\u304b\u3089\u3060\u3002<\/p>\n<p>\u3060\u304b\u3089\u89e3\u6c7a\u7b56\u306f\u300c\u5909\u63db\u300d\u3067\u306f\u306a\u304f\u300c<strong>\u305d\u306e\u74b0\u5883\u306b <code>flat<\/code> \u306e\u5b9f\u88c5\u3092\u6ce8\u5165\u3059\u308b<\/strong>\u300d\u3053\u3068\u3002\u3053\u306e\u5b9f\u88c5\u306e\u584a\u3092\u63d0\u4f9b\u3059\u308b\u306e\u304c <code>core-js<\/code> \u3060\u3002<\/p>\n<p>&gt; \u3064\u307e\u308a\u3001Babel\uff08\u30c8\u30e9\u30f3\u30b9\u30d1\u30a4\u30eb\uff09\u306f\u69cb\u6587\u3092\u89e3\u6c7a\u3057\u3001core-js\uff08\u30dd\u30ea\u30d5\u30a3\u30eb\uff09\u306fAPI\u3092\u89e3\u6c7a\u3059\u308b\u3002\u5b88\u5099\u7bc4\u56f2\u304c\u305d\u3082\u305d\u3082\u9055\u3046\u3002<\/p>\n<h2>@babel\/preset-env \u304c\u8abf\u6574\u5f79\u306b\u306a\u308b<\/h2>\n<p><code>@babel\/preset-env<\/code> \u306f\u300c\u30bf\u30fc\u30b2\u30c3\u30c8\u74b0\u5883\u306b\u5fdc\u3058\u3066\u5fc5\u8981\u306a\u5909\u63db\u3068\u30dd\u30ea\u30d5\u30a3\u30eb\u3092\u9078\u3076\u300d\u30d7\u30ea\u30bb\u30c3\u30c8\u3060\u3002\u9375\u306f <strong><code>targets<\/code><\/strong> \u3068 <strong><code>useBuiltIns<\/code><\/strong> \u306e2\u3064\u3002<\/p>\n<h3>targets\uff1a\u3069\u3053\u307e\u3067\u5bfe\u5fdc\u3059\u308b\u304b<\/h3>\n<p>\u5bfe\u5fdc\u3057\u305f\u3044\u30d6\u30e9\u30a6\u30b6\u30fb\u74b0\u5883\u3092 Browserslist \u306e\u8a18\u6cd5\u3067\u6307\u5b9a\u3059\u308b\u3002<\/p>\n<pre class=\"lang:default decode:true\"># .browserslistrc\n&gt; 0.5%\nlast 2 versions\nnot dead<\/pre>\n<p>\u30bf\u30fc\u30b2\u30c3\u30c8\u304c\u65b0\u3057\u3044\u307b\u3069\u5909\u63db\u3068\u30dd\u30ea\u30d5\u30a3\u30eb\u306f\u6e1b\u308a\u3001\u51fa\u529b\u306f\u8efd\u304f\u306a\u308b\u3002\u7518\u304f\u3059\u308b\u307b\u3069\u592a\u308b\u3002<\/p>\n<p>&gt; <strong>Babel 8\uff082026-06 \u306b\u5b89\u5b9a\u7248\u30ea\u30ea\u30fc\u30b9\uff09\u3067\u306e\u91cd\u8981\u306a\u5909\u66f4<\/strong>\uff1aBabel 7 \u306f <code>targets<\/code> \u672a\u6307\u5b9a\u3060\u3068\u5168\u30d6\u30e9\u30a6\u30b6\uff08\u5b9f\u8cea ES5\uff09\u307e\u3067\u843d\u3068\u3057\u3066\u3044\u305f\u304c\u3001Babel 8 \u306e <code>@babel\/preset-env<\/code> \u306f\u30c7\u30d5\u30a9\u30eb\u30c8\u3067 ES5 \u3078\u30b3\u30f3\u30d1\u30a4\u30eb\u3057\u306a\u304f\u306a\u308a\u3001Browserslist \u306e <code>defaults<\/code>\uff08\u304a\u304a\u3088\u305d ES2023 \u76f8\u5f53\uff09\u306b\u5f93\u3046\u3088\u3046\u306b\u306a\u3063\u305f\u3002\u3064\u307e\u308a <strong>\u53e4\u3044\u30d6\u30e9\u30a6\u30b6\u3084 ES5 \u307e\u3067\u78ba\u5b9f\u306b\u843d\u3068\u3057\u305f\u3044\u306a\u3089\u3001<code>targets<\/code> \u3082\u3057\u304f\u306f <code>.browserslistrc<\/code> \u3092\u660e\u793a\u6307\u5b9a\u3059\u308b\u5fc5\u8981\u304c\u3042\u308b<\/strong>\u3002\u6307\u5b9a\u3092\u7701\u304f\u3068\u300c\u53e4\u3044\u74b0\u5883\u5411\u3051\u306e\u3064\u3082\u308a\u304c\u3001\u5b9f\u306f ES2023 \u6b62\u307e\u308a\u3060\u3063\u305f\u300d\u3068\u3044\u3046\u53d6\u308a\u9055\u3048\u304c\u8d77\u304d\u3084\u3059\u3044\u3002\u9006\u306b\u8a00\u3048\u3070\u3001\u5bfe\u5fdc\u7bc4\u56f2\u3092\u660e\u793a\u3057\u3066\u304a\u304f\u3053\u3068\u306e\u91cd\u8981\u6027\u304c Babel 8 \u3067\u4e00\u6bb5\u4e0a\u304c\u3063\u305f\u3002<\/p>\n<h3>useBuiltIns\uff1a\u30dd\u30ea\u30d5\u30a3\u30eb\u306e\u5165\u308a\u65b9<\/h3>\n<p><code>useBuiltIns<\/code> \u304c\u3001core-js \u306e\u30dd\u30ea\u30d5\u30a3\u30eb\u3092\u3069\u3046\u6ce8\u5165\u3059\u308b\u304b\u3092\u6c7a\u3081\u308b\u6700\u91cd\u8981\u30aa\u30d7\u30b7\u30e7\u30f3\u3060\u3002<\/p>\n<ul>\n<li><strong><code>false<\/code><\/strong>\uff08\u30c7\u30d5\u30a9\u30eb\u30c8\uff09: \u30dd\u30ea\u30d5\u30a3\u30eb\u3092\u4e00\u5207\u6ce8\u5165\u3057\u306a\u3044\u3002\u69cb\u6587\u5909\u63db\u3060\u3051\u3002<code>flat<\/code> \u843d\u3061\u306f\u3053\u306e\u72b6\u614b\u3067\u8d77\u304d\u308b\u3002<\/li>\n<li><strong><code>entry<\/code><\/strong>: \u30a8\u30f3\u30c8\u30ea\u30fc\u306b\u66f8\u3044\u305f <code>import \"core-js\"<\/code> \u3092\u3001targets \u306b\u57fa\u3065\u3044\u3066\u5fc5\u8981\u306a\u30e2\u30b8\u30e5\u30fc\u30eb\u7fa4\u3078\u5c55\u958b\u3059\u308b\u3002<\/li>\n<li><strong><code>usage<\/code><\/strong>: \u30b3\u30fc\u30c9\u4e2d\u3067\u5b9f\u969b\u306b\u4f7f\u3063\u3066\u3044\u308bAPI\u3092\u691c\u51fa\u3057\u3001\u30d5\u30a1\u30a4\u30eb\u3054\u3068\u306b\u5fc5\u8981\u306a\u30dd\u30ea\u30d5\u30a3\u30eb\u3060\u3051\u3092\u81ea\u52d5 import \u3059\u308b\u3002<\/li>\n<\/ul>\n<pre class=\"lang:default decode:true\">\/\/ babel.config.js\uff08\u30a2\u30d7\u30ea\u5411\u3051\u306e\u57fa\u672c\u5f62\uff09\nmodule.exports = {\n  presets: [\n    [\"@babel\/preset-env\", {\n      useBuiltIns: \"usage\",\n      corejs: { version: \"3.51\", proposals: false },\n    }],\n  ],\n};<\/pre>\n<p><code>usage<\/code> \u306b\u3059\u308b\u3068\u3001<code>flat<\/code> \u3092\u4f7f\u3063\u3066\u3044\u308b\u30d5\u30a1\u30a4\u30eb\u306b\u3060\u3051\u5bfe\u5fdc\u30dd\u30ea\u30d5\u30a3\u30eb\u304c\u81ea\u52d5\u3067\u5dee\u3057\u8fbc\u307e\u308c\u308b\u3002<\/p>\n<pre class=\"lang:default decode:true\">\/\/ src\/feature.js\nconst result = [1, 2, 3].flat();\n\/\/ \u2193 \u30d3\u30eb\u30c9\u6642\u306b\u81ea\u52d5\u6ce8\u5165\u3055\u308c\u308b\u30a4\u30e1\u30fc\u30b8\n\/\/ import \"core-js\/modules\/es.array.flat.js\";<\/pre>\n<p><code>corejs<\/code> \u306e <code>version<\/code> \u306b\u306f\u57f7\u7b46\u6642\u70b9\u306e\u6700\u65b0\u3067\u3042\u308b 3.51 \u3092\u7f6e\u3044\u305f\u3002core-js \u306f\u30e1\u30b8\u30e3\u30fc\u304c\u9577\u304f 3 \u7cfb\u306e\u307e\u307e\u3067\u3001API\u30fb\u4f7f\u3044\u65b9\u81ea\u4f53\u306f\u5909\u308f\u3063\u3066\u3044\u306a\u3044\u3002\u3053\u3053\u306f\u304a\u4f7f\u3044\u306e <code>package.json<\/code> \u306e <code>core-js<\/code> \u30d0\u30fc\u30b8\u30e7\u30f3\u306b\u305d\u306e\u307e\u307e\u5408\u308f\u305b\u3066\u8aad\u307f\u66ff\u3048\u3066\u3088\u3044\uff08<code>useBuiltIns<\/code> \/ <code>corejs:3<\/code> \u306e\u57fa\u672c\u8a2d\u8a08\u306f Babel 8 \u3067\u3082\u305d\u306e\u307e\u307e\u6709\u52b9\uff09\u3002<\/p>\n<h2>\u30a2\u30d7\u30ea\u306f useBuiltIns\u3001\u30e9\u30a4\u30d6\u30e9\u30ea\u306f transform-runtime<\/h2>\n<p>\u5b9f\u52d9\u3067\u9593\u9055\u3048\u3084\u3059\u3044\u306e\u304c\u3053\u3053\u3060\u3002<code>useBuiltIns<\/code> \u306e\u30dd\u30ea\u30d5\u30a3\u30eb\u6ce8\u5165\u306f <code>Array.prototype<\/code> \u306a\u3069\u306e<strong>\u30b0\u30ed\u30fc\u30d0\u30eb\u3092\u66f8\u304d\u63db\u3048\u308b<\/strong>\u3002\u30a2\u30d7\u30ea\u306e\u6700\u7d42\u6210\u679c\u7269\u306a\u3089\u305d\u308c\u3067\u3088\u3044\u304c\u3001<strong>npm \u3067\u914d\u5e03\u3059\u308b\u30e9\u30a4\u30d6\u30e9\u30ea<\/strong>\u304c\u30b0\u30ed\u30fc\u30d0\u30eb\u3092\u6c5a\u67d3\u3059\u308b\u3068\u3001\u5229\u7528\u5074\u306e\u74b0\u5883\u3092\u58ca\u3057\u304b\u306d\u306a\u3044\u3002<\/p>\n<p>\u30e9\u30a4\u30d6\u30e9\u30ea\u5074\u3067\u306f <code>@babel\/plugin-transform-runtime<\/code> + <code>@babel\/runtime-corejs3<\/code> \u3092\u4f7f\u3044\u3001\u30b0\u30ed\u30fc\u30d0\u30eb\u3092\u6c5a\u3055\u306a\u3044\u5f62\u3067\u30dd\u30ea\u30d5\u30a3\u30eb\u3092\u53c2\u7167\u3059\u308b\u306e\u304c\u5b9a\u77f3\u3060\u3002<\/p>\n<pre class=\"lang:default decode:true\">\/\/ babel.config.js\uff08\u30e9\u30a4\u30d6\u30e9\u30ea\u5411\u3051\uff09\nmodule.exports = {\n  presets: [\"@babel\/preset-env\"],\n  plugins: [[\"@babel\/plugin-transform-runtime\", { corejs: 3 }]],\n};<\/pre>\n<p><strong>\u30a2\u30d7\u30ea\u306f <code>useBuiltIns<\/code>\u3001\u30e9\u30a4\u30d6\u30e9\u30ea\u306f <code>transform-runtime<\/code><\/strong> \u3068\u899a\u3048\u3066\u304a\u304f\u3068\u5224\u65ad\u3092\u9593\u9055\u3048\u306b\u304f\u3044\u3002<\/p>\n<h2>\u78ba\u8a8d\u65b9\u6cd5<\/h2>\n<p>\u610f\u56f3\u3069\u304a\u308a\u306b\u30dd\u30ea\u30d5\u30a3\u30eb\u304c\u5165\u3063\u3066\u3044\u308b\u304b\u306f\u3001\u30d3\u30eb\u30c9\u51fa\u529b\u3092\u76f4\u63a5\u898b\u308b\u306e\u304c\u4e00\u756a\u901f\u3044\u3002<\/p>\n<ol>\n<li><code>useBuiltIns: \"usage\"<\/code> \u3067\u30d3\u30eb\u30c9\u3057\u3001\u751f\u6210\u7269\u306b <code>core-js\/modules\/es.array.flat<\/code> \u76f8\u5f53\u306e import \u304c\u542b\u307e\u308c\u3066\u3044\u308b\u304b\u78ba\u8a8d\u3059\u308b\u3002<\/li>\n<li><code>targets<\/code> \u3092\u65b0\u3057\u3044\u30d6\u30e9\u30a6\u30b6\u3060\u3051\u306b\u7d5e\u308b\u3068\u30dd\u30ea\u30d5\u30a3\u30eb\u304c\u6d88\u3048\u3001\u53e4\u3044\u30d6\u30e9\u30a6\u30b6\u3092\u8db3\u3059\u3068\u5897\u3048\u308b\u3053\u3068\u3092\u78ba\u8a8d\u3059\u308b\u3002<\/li>\n<li>preset-env \u306b <code>debug: true<\/code> \u3092\u6e21\u3059\u3068\u3001\u30d3\u30eb\u30c9\u6642\u306b\u3069\u306e\u5909\u63db\u30fb\u30dd\u30ea\u30d5\u30a3\u30eb\u304c\u6709\u52b9\u5316\u3055\u308c\u305f\u304b\u3092\u30ed\u30b0\u3067\u78ba\u8a8d\u3067\u304d\u308b\u3002<\/li>\n<\/ol>\n<pre class=\"lang:default decode:true\">[\"@babel\/preset-env\", { debug: true }]<\/pre>\n<h2>\u6ce8\u610f\u70b9<\/h2>\n<ul>\n<li><strong><code>corejs<\/code> \u306e\u30d0\u30fc\u30b8\u30e7\u30f3\u306f\u5fc5\u305a\u660e\u793a\u3059\u308b\u3002<\/strong> \u7701\u7565\u3059\u308b\u3068\u8b66\u544a\u304c\u51fa\u308b\u3046\u3048\u3001\u610f\u56f3\u3057\u306a\u3044\u30d0\u30fc\u30b8\u30e7\u30f3\u306e\u30dd\u30ea\u30d5\u30a3\u30eb\u304c\u4f7f\u308f\u308c\u3046\u308b\u3002<code>package.json<\/code> \u306e <code>core-js<\/code> \u3068\u63c3\u3048\u308b\u3002<\/li>\n<li><strong><code>proposals<\/code> \u3092\u5b89\u6613\u306b\u6709\u52b9\u5316\u3057\u306a\u3044\u3002<\/strong> \u4ed5\u69d8\u78ba\u5b9a\u524d\u306eAPI\u307e\u3067\u30dd\u30ea\u30d5\u30a3\u30eb\u3059\u308b\u3068\u3001\u5c06\u6765\u306e\u4ed5\u69d8\u5909\u66f4\u3067\u6319\u52d5\u304c\u5909\u308f\u308b\u30ea\u30b9\u30af\u3092\u62b1\u3048\u308b\u3002<\/li>\n<li><strong>\u30bf\u30fc\u30b2\u30c3\u30c8\u3092\u5e83\u3052\u3059\u304e\u306a\u3044\u3002<\/strong> <code>targets<\/code> \u3092\u7518\u304f\u3059\u308b\u307b\u3069\u5909\u63db\u3068\u30dd\u30ea\u30d5\u30a3\u30eb\u304c\u5897\u3048\u3001\u30d0\u30f3\u30c9\u30eb\u304c\u592a\u308b\u3002\u5b9f\u30e6\u30fc\u30b6\u30fc\u306e\u74b0\u5883\u30c7\u30fc\u30bf\u3067\u7d5e\u308b\u3002<\/li>\n<li><strong><code>Promise<\/code> \u306a\u3069\u306e\u5927\u7269\u30dd\u30ea\u30d5\u30a3\u30eb\u306f\u30b3\u30b9\u30c8\u304c\u5927\u304d\u3044\u3002<\/strong> \u5bfe\u5fdc\u30d6\u30e9\u30a6\u30b6\u8981\u4ef6\u306f\u6280\u8853\u3067\u306f\u306a\u304f\u30d3\u30b8\u30cd\u30b9\u5224\u65ad\u3068\u3057\u3066\u63e1\u3063\u3066\u304a\u304f\u3002<\/li>\n<li><strong>Babel 8 \u3067\u306f <code>loose<\/code> \/ <code>spec<\/code> \u30aa\u30d7\u30b7\u30e7\u30f3\u304c\u5ec3\u6b62\u3055\u308c\u3001\u30c8\u30c3\u30d7\u30ec\u30d9\u30eb\u306e <code>assumptions<\/code> \u306b\u7d71\u5408\u3055\u308c\u305f\u3002<\/strong> Babel 7 \u306e\u8a2d\u5b9a\u304b\u3089\u79fb\u884c\u3059\u308b\u5834\u5408\u306f\u3001\u30d7\u30e9\u30b0\u30a4\u30f3\u3054\u3068\u306b\u6563\u3089\u3070\u3063\u3066\u3044\u305f <code>loose<\/code> \u6307\u5b9a\u3092 <code>assumptions<\/code> \u306b\u66f8\u304d\u63db\u3048\u308b\u3002<\/li>\n<li><strong>Babel 8 \u672c\u4f53\u306f ESM-only \u3067\u914d\u5e03\u3055\u308c\u308b\uff08\u5168\u30d1\u30c3\u30b1\u30fc\u30b8\u306b TypeScript \u578b\u3092\u540c\u68b1\uff09\u3002<\/strong> \u30d7\u30ed\u30b0\u30e9\u30e0\u304b\u3089 <code>@babel\/core<\/code> \u306a\u3069\u3092 <code>require<\/code> \u3057\u3066\u547c\u3073\u51fa\u3057\u3066\u3044\u308b\u7b87\u6240\u304c\u3042\u308c\u3070 <code>import<\/code> \u3078\u306e\u79fb\u884c\u304c\u5fc5\u8981\u306b\u306a\u308b\u3002\u8a2d\u5b9a\u30d5\u30a1\u30a4\u30eb\uff08<code>babel.config.js<\/code>\uff09\u7d4c\u7531\u3067\u4f7f\u3046\u901a\u5e38\u306e\u69cb\u6210\u306b\u306f\u5f71\u97ff\u3057\u306a\u3044\u3002<\/li>\n<\/ul>\n<h2>\u307e\u3068\u3081<\/h2>\n<ul>\n<li><strong>\u30c8\u30e9\u30f3\u30b9\u30d1\u30a4\u30eb = \u69cb\u6587\u306e\u66f8\u304d\u63db\u3048<\/strong>\u3002Babel\u672c\u4f53\u306e\u4ed5\u4e8b\u3002\u5b9f\u884c\u74b0\u5883\u306b\u4f55\u3082\u8db3\u3055\u306a\u3044\u3002<\/li>\n<li><strong>\u30dd\u30ea\u30d5\u30a3\u30eb = API\u306e\u5f8c\u4ed8\u3051\u5b9f\u88c5<\/strong>\u3002core-js \u304c\u5b9f\u4f53\u3092\u63d0\u4f9b\u3059\u308b\u3002<\/li>\n<li><code>@babel\/preset-env<\/code> \u306f <code>targets<\/code> \u3092\u898b\u3066\u300c\u5fc5\u8981\u306a\u5909\u63db\u300d\u3068\u300c\u5fc5\u8981\u306a\u30dd\u30ea\u30d5\u30a3\u30eb\u300d\u3092\u9078\u3073\u3001<code>useBuiltIns<\/code> \u3067\u30dd\u30ea\u30d5\u30a3\u30eb\u306e\u5165\u308a\u65b9\u3092\u5236\u5fa1\u3059\u308b\u3002Babel 8 \u304b\u3089\u306f\u30c7\u30d5\u30a9\u30eb\u30c8\u304c ES5 \u3067\u306f\u306a\u304f Browserslist \u306e <code>defaults<\/code>\uff08\u2252ES2023\uff09\u306b\u306a\u3063\u305f\u305f\u3081\u3001\u53e4\u3044\u74b0\u5883\u5bfe\u5fdc\u3067\u306f <code>targets<\/code> \u306e\u660e\u793a\u304c\u3044\u3063\u305d\u3046\u91cd\u8981\u306b\u306a\u3063\u305f\u3002<\/li>\n<li>\u30a2\u30d7\u30ea\u306f <code>useBuiltIns: \"usage\"<\/code>\u3001\u30e9\u30a4\u30d6\u30e9\u30ea\u306f <code>transform-runtime<\/code> \u304c\u57fa\u672c\u7dda\u3002<\/li>\n<li>\u300cBabel\u304c\u5168\u90e8\u3084\u3063\u3066\u304f\u308c\u308b\u300d\u3067\u306f\u306a\u304f\u300cBabel\u306f\u69cb\u6587\u3001core-js\u306fAPI\u300d\u3068\u5207\u308a\u5206\u3051\u308b\u3068\u3001<code>flat is not a function<\/code> \u7cfb\u306e\u4e8b\u6545\u3082\u3001\u30d0\u30f3\u30c9\u30eb\u80a5\u5927\u306e\u5224\u65ad\u3082\u3001\u898b\u901a\u3057\u3088\u304f\u6271\u3048\u308b\u3002<\/li>\n<\/ul>\n<p>Sources:<\/p>\n<ul>\n<li><a href=\"https:\/\/babeljs.io\/blog\/2026\/06\/16\/8.0.0\">Releasing Babel 8 today: ESM-only, drop ES5 default, and a smooth migration path \u00b7 Babel<\/a><\/li>\n<li><a href=\"https:\/\/babeljs.io\/docs\/v8-migration\">Upgrade to Babel 8 \u00b7 Babel<\/a><\/li>\n<li><a href=\"https:\/\/babeljs.io\/docs\/babel-preset-env\">@babel\/preset-env \u00b7 Babel<\/a><\/li>\n<li><a href=\"https:\/\/www.npmjs.com\/package\/core-js\">core-js - npm<\/a><\/li>\n<\/ul>\n","protected":false},"excerpt":{"rendered":"<p>\u30e2\u30c0\u30f3\u306a\u30d5\u30ed\u30f3\u30c8\u30a8\u30f3\u30c9\u958b\u767a\u3067\u306f\u3001\u6700\u65b0\u306eJavaScript\u69cb\u6587\u3092\u66f8\u3044\u3066\u3082\u53e4\u3044\u30d6\u30e9\u30a6\u30b6\u3067\u52d5\u304f\u3002\u3053\u308c\u3092\u652f\u3048\u3066\u3044\u308b\u306e\u304cBabel\u3060\u3002\u3057\u304b\u3057\u300cBabel\u3092\u4f7f\u3048\u3070\u5168\u90e8\u3088\u3057\u306a\u306b\u5909\u63db\u3057\u3066\u304f\u308c\u308b\u300d\u3068\u7406\u89e3\u3057\u3066\u3044\u308b\u3068\u3001async\u306f\u52d5\u304f\u306e\u306bArray.proto\u2026<\/p>\n","protected":false},"author":1,"featured_media":3671,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_newsletter_access":"","_jetpack_dont_email_post_to_subs":false,"_jetpack_newsletter_tier_id":0,"_jetpack_memberships_contains_paywalled_content":false,"sns_share_botton_hide":"","vkExUnit_sns_title":"","_vk_print_noindex":"","sitemap_hide":"","_veu_custom_css":"","veu_display_promotion_alert":"","vkexunit_cta_each_option":"","_lightning_design_setting":[],"_jetpack_hide_featured_image":false,"_jetpack_featured_image_duplicate_dismissed":0,"_jetpack_feature_clip_id":0,"_jetpack_memberships_contains_paid_content":false,"footnotes":"","jetpack_publicize_message":"","jetpack_publicize_feature_enabled":true,"jetpack_social_post_already_shared":true,"jetpack_social_options":{"image_generator_settings":{"template":"highway","default_image_id":0,"font":"","enabled":false},"version":2},"jetpack_post_was_ever_published":false},"categories":[36],"tags":[64,365,584],"class_list":["post-3672","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-javascript-memorandum","tag-api","tag-javascript","tag-js"],"veu_head_title_object":{"title":"","add_site_title":""},"jetpack_publicize_connections":[],"jetpack-related-posts":[],"jetpack_sharing_enabled":true,"jetpack_featured_media_url":"https:\/\/qol-kk.com\/wp2\/wp-content\/uploads\/2026\/11\/20261024-00mvllzw-thumbnail.jpg","_links":{"self":[{"href":"https:\/\/qol-kk.com\/wp2\/wp-json\/wp\/v2\/posts\/3672","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/qol-kk.com\/wp2\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/qol-kk.com\/wp2\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/qol-kk.com\/wp2\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/qol-kk.com\/wp2\/wp-json\/wp\/v2\/comments?post=3672"}],"version-history":[{"count":1,"href":"https:\/\/qol-kk.com\/wp2\/wp-json\/wp\/v2\/posts\/3672\/revisions"}],"predecessor-version":[{"id":3673,"href":"https:\/\/qol-kk.com\/wp2\/wp-json\/wp\/v2\/posts\/3672\/revisions\/3673"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/qol-kk.com\/wp2\/wp-json\/wp\/v2\/media\/3671"}],"wp:attachment":[{"href":"https:\/\/qol-kk.com\/wp2\/wp-json\/wp\/v2\/media?parent=3672"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/qol-kk.com\/wp2\/wp-json\/wp\/v2\/categories?post=3672"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/qol-kk.com\/wp2\/wp-json\/wp\/v2\/tags?post=3672"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}