Prepare package build scripts and setup

Author: przemyslawzalewski

.gitignore

@@ -59,3 +59,6 @@ typings/
 
 # next.js build output
 .next
+
+index.cjs.js
+index.umd.js

.npmignore

@@ -0,0 +1 @@
+regenerate.js

package-lock.json

@@ -2,14 +2,18 @@
   "name": "@sandstreamdev/std",
   "version": "0.1.0",
   "description": "",
-  "main": "index.js",
-  "module": "index.js",
   "type": "module",
+  "module": "index.js",
+  "main": "index.cjs.js",
+  "browser": "index.umd.js",
   "sideEffects": false,
   "scripts": {
-    "prettier": "prettier \"**/*.{js,json,md}\"",
+    "build": "npm run regenerate && rollup -c",
+    "prepare": "npm run build",
+    "prettier:check": "npm run prettier -- --check",
     "prettier:fix": "npm run prettier -- --write",
-    "prettier:check": "npm run prettier -- --check"
+    "prettier": "prettier \"**/*.{js,json,md}\"",
+    "regenerate": "node --experimental-modules regenerate.js && npm run prettier:fix"
   },
   "repository": {
     "type": "git",
@@ -26,6 +30,7 @@
   },
   "homepage": "https://github.com/sandstreamdev/std#readme",
   "devDependencies": {
-    "prettier": "^1.18.2"
+    "prettier": "^1.18.2",
+    "rollup": "^1.22.0"
   }
 }

package.json

@@ -0,0 +1,84 @@
+import { promises } from "fs";
+import path from "path";
+
+const { readdir: readDirectoryAsync, writeFile: writeFileAsync } = promises;
+
+const [, , cwd = process.cwd()] = process.argv;
+
+const mapping = {
+  function: "_function"
+};
+
+const ignoredFiles = [
+  ".gitignore",
+  "index.js",
+  "LICENSE",
+  "package-lock.json",
+  "package.json",
+  "README.md",
+  "regenerate.js",
+  "rollup.config.js"
+];
+
+const ignoredDirectories = [".git", "node_modules"];
+
+const identifier = name => mapping[name] || name;
+
+const main = async cwd => {
+  console.log(`Indexing files in ${cwd}...`);
+
+  const entries = await readDirectoryAsync(cwd, { withFileTypes: true });
+  const files = entries
+    .filter(x => x.isFile())
+    .map(x => x.name)
+    .filter(x => !ignoredFiles.includes(x));
+  const directories = entries
+    .filter(x => x.isDirectory())
+    .map(x => x.name)
+    .filter(x => !ignoredDirectories.includes(x));
+
+  for (const directory of directories) {
+    await main(path.join(cwd, directory));
+  }
+
+  const submodules = files.map(filePath => {
+    const { base: fileName } = path.parse(filePath);
+    const splitted = fileName.split(".");
+    const id = identifier(splitted.slice(0, splitted.length - 1).join("_"));
+    const extension = `.${splitted[splitted.length - 1]}`;
+
+    return [fileName, id, extension];
+  });
+
+  const dependencies = [
+    ...submodules,
+    ...directories.map(x => [`${x}/index.js`, identifier(x), ""])
+  ];
+
+  const importDeclarations = dependencies
+    .map(([fileName, id]) =>
+      id !== "index" ? `import ${id} from './${fileName}'` : ""
+    )
+    .join("\r\n");
+
+  const exportDeclarationBody = dependencies
+    .map(([, id]) => (id !== "index" ? id : ""))
+    .join(", ");
+
+  const exportDeclaration = `export { ${exportDeclarationBody} }`;
+  const defaultExport = `export default { ${exportDeclarationBody} }`;
+
+  console.log(`Indexed files in ${cwd}:`);
+
+  const moduleContents = [
+    importDeclarations,
+    exportDeclaration,
+    defaultExport
+  ].join("\r\n\r\n");
+
+  console.log(moduleContents);
+
+  await writeFileAsync(path.join(cwd, "index.js"), moduleContents);
+};
+
+main(cwd);

regenerate.js

@@ -0,0 +1,15 @@
+export default {
+  input: "index.js",
+  output: [
+    {
+      exports: "named",
+      file: "index.cjs.js",
+      format: "cjs"
+    },
+    {
+      file: "index.umd.js",
+      format: "umd",
+      name: "@sandstreamdev/std"
+    }
+  ]
+};