babel/packages/babel-helpers/scripts/generate-helpers.js
Nicolò Ribaudo f63d73c94e
Allow putting helpers in individual files (#13190)
* Allow putting helpers in individual files

* Lint

* Also move `objectSpread2` (to show an helper with deps)

* Update fixture and package.json

* fixture
2021-04-22 20:45:52 +02:00

61 lines
1.5 KiB
JavaScript

import fs from "fs";
import { join } from "path";
import { URL } from "url";
const HELPERS_FOLDER = new URL("../src/helpers", import.meta.url);
const IGNORED_FILES = new Set(["package.json"]);
export default async function generateAsserts() {
let output = `/*
* This file is auto-generated! Do not modify it directly.
* To re-generate run 'make build'
*/
import template from "@babel/template";
`;
for (const file of (await fs.promises.readdir(HELPERS_FOLDER)).sort()) {
if (IGNORED_FILES.has(file)) continue;
const [helperName] = file.split(".");
const isValidId = isValidBindingIdentifier(helperName);
const varName = isValidId ? helperName : `_${helperName}`;
const fileContents = await fs.promises.readFile(
join(HELPERS_FOLDER.pathname, file),
"utf8"
);
const { minVersion } = fileContents.match(
/^\s*\/\*\s*@minVersion\s+(?<minVersion>\S+)\s*\*\/\s*$/m
).groups;
// TODO: We can minify the helpers in production
const source = fileContents
// Remove comments
.replace(/\/\*[^]*?\*\/|\/\/.*/g, "")
// Remove multiple newlines
.replace(/\n{2,}/g, "\n");
const intro = isValidId
? "export "
: `export { ${varName} as ${helperName} }\n`;
output += `\n${intro}const ${varName} = {
minVersion: ${JSON.stringify(minVersion)},
ast: () => template.program.ast(${JSON.stringify(source)})
};\n`;
}
return output;
}
function isValidBindingIdentifier(name) {
try {
Function(`var ${name}`);
return true;
} catch {
return false;
}
}