Add node modules and new code for release (#39)

Co-authored-by: tbarnes94 <tbarnes94@users.noreply.github.com>

node_modules/babel-preset-current-node-syntax/LICENSE

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+MIT License
+
+Copyright (c) 2020 Nicolò Ribaudo and other contributors
+
+Permission is hereby granted, free of charge, to any person obtaining
+a copy of this software and associated documentation files (the
+"Software"), to deal in the Software without restriction, including
+without limitation the rights to use, copy, modify, merge, publish,
+distribute, sublicense, and/or sell copies of the Software, and to
+permit persons to whom the Software is furnished to do so, subject to
+the following conditions:
+
+The above copyright notice and this permission notice shall be
+included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
+EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
+NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
+LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
+OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
+WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

node_modules/babel-preset-current-node-syntax/README.md

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+# `babel-preset-current-node-syntax`
+
+> A Babel preset that enables parsing of proposals supported by the current Node.js version.
+
+## Installation
+
+If you are using yarn:
+```
+yarn add --dev babel-preset-current-node-syntax
+```
+
+If you are using npm:
+```
+npm install --save-dev babel-preset-current-node-syntax
+```
+
+## Contributing
+
+PRs are welcome! The codebase is so small that I didn't setup a linter, but try
+to match the style of the existing code.
+
+You can run tests with the following command:
+```
+yarn node test/index.js
+```
+
+The `test/fixtures.json` file contains a bunch of syntax tests, alongside with
+the minimum supported node version for each of them. Babel should throw on
+older versions, without support for that given syntax.
+All the tests are run using `@babel/parser@7.0.0`.

node_modules/babel-preset-current-node-syntax/package.json

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+{
+  "name": "babel-preset-current-node-syntax",
+  "version": "0.1.3",
+  "description": "A Babel preset that enables parsing of proposals supported by the current Node.js version.",
+  "main": "src/index.js",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/nicolo-ribaudo/babel-preset-current-node-syntax.git"
+  },
+  "author": {
+    "name": "Nicolò Ribaudo",
+    "url": "https://github.com/nicolo-ribaudo"
+  },
+  "scripts": {
+    "test": "node ./test/index.js"
+  },
+  "dependencies": {
+    "@babel/plugin-syntax-async-generators": "^7.8.4",
+    "@babel/plugin-syntax-bigint": "^7.8.3",
+    "@babel/plugin-syntax-class-properties": "^7.8.3",
+    "@babel/plugin-syntax-import-meta": "^7.8.3",
+    "@babel/plugin-syntax-json-strings": "^7.8.3",
+    "@babel/plugin-syntax-logical-assignment-operators": "^7.8.3",
+    "@babel/plugin-syntax-nullish-coalescing-operator": "^7.8.3",
+    "@babel/plugin-syntax-numeric-separator": "^7.8.3",
+    "@babel/plugin-syntax-object-rest-spread": "^7.8.3",
+    "@babel/plugin-syntax-optional-catch-binding": "^7.8.3",
+    "@babel/plugin-syntax-optional-chaining": "^7.8.3"
+  },
+  "peerDependencies": {
+    "@babel/core": "^7.0.0"
+  },
+  "devDependencies": {
+    "@babel/core": "7.0.0"
+  },
+  "resolutions": {
+    "@babel/parser": "7.0.0"
+  },
+  "license": "MIT"
+}

node_modules/babel-preset-current-node-syntax/src/index.js

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+const tests = {
+  // ECMAScript 2018
+  "object-rest-spread": ["({ ...{} })", "({ ...x } = {})"], // Babel 7.2.0
+  "async-generators": ["async function* f() {}"], //  Babel 7.2.0
+
+  // ECMAScript 2019
+  "optional-catch-binding": ["try {} catch {}"], // Babel 7.2.0
+  "json-strings": ["'\\u2028'"], // Babel 7.2.0
+
+  // ECMAScript 2020
+  "bigint": ["1n"], // Babel 7.8.0
+  "optional-chaining": ["a?.b"], // Babel 7.9.0
+  "nullish-coalescing-operator": ["a ?? b"], // Babel 7.9.0
+  // import.meta is handled manually
+
+  // Stage 3
+  "numeric-separator": ["1_2"],
+  "class-properties": [
+    "(class { x = 1 })",
+    "(class { #x = 1 })",
+    "(class { #x() {} })",
+  ],
+  "logical-assignment-operators": ["a ||= b", "a &&= b", "a ??= c"],
+};
+
+const plugins = [];
+const works = (test) => {
+  try {
+    // Wrap the test in a function to only test the syntax, without executing it
+    (0, eval)(`(() => { ${test} })`);
+    return true;
+  } catch (_error) {
+    return false;
+  }
+};
+
+for (const [name, cases] of Object.entries(tests)) {
+  if (cases.some(works)) {
+    plugins.push(require.resolve(`@babel/plugin-syntax-${name}`));
+  }
+}
+
+// import.meta is only allowed in modules, and modules can only be evaluated
+// synchronously. For this reason, we cannot detect import.meta support at
+// runtime. It is supported starting from 10.4, so we can check the version.
+const major = parseInt(process.versions.node, 10);
+const minor = parseInt(process.versions.node.match(/^\d+\.(\d+)/)[1], 10);
+if (major > 10 || (major === 10 && minor > 4)) {
+  plugins.push(require.resolve("@babel/plugin-syntax-import-meta"));
+}
+
+module.exports = () => ({ plugins });