refactor: separate library and cli entry point (#250)

mkshims.ts

@@ -5,11 +5,6 @@ import path                         from 'path';
 import {Engine}                     from './sources/Engine';
 import {SupportedPackageManagerSet} from './sources/types';
 
-function shouldGenerateShim(name: string) {
-  // No filtering needed at the moment
-  return true;
-}
-
 const engine = new Engine();
 
 const distDir = path.join(__dirname, `dist`);
@@ -23,26 +18,33 @@ fs.mkdirSync(shimsDir, {recursive: true});
 fs.mkdirSync(physicalNodewinDir, {recursive: true});
 
 async function main() {
+  const corepackPath = path.join(distDir, `corepack.js`);
+  fs.writeFileSync(corepackPath, [
+    `#!/usr/bin/env node`,
+    `require('./lib/corepack.cjs').runMain(process.argv.slice(2));`,
+  ].join(`\n`));
+  fs.chmodSync(corepackPath, 0o755);
+
   for (const packageManager of SupportedPackageManagerSet) {
     const binSet = engine.getBinariesFor(packageManager);
 
     for (const binaryName of binSet) {
       const entryPath = path.join(distDir, `${binaryName}.js`);
       const entryScript = [
-        `#!/usr/bin/env node\n`,
-        `require('./corepack').runMain(['${binaryName}', ...process.argv.slice(2)]);\n`,
-      ].join(``);
+        `#!/usr/bin/env node`,
+        `require('./lib/corepack.cjs').runMain(['${binaryName}', ...process.argv.slice(2)]);`,
+      ].join(`\n`);
 
       fs.writeFileSync(entryPath, entryScript);
       fs.chmodSync(entryPath, 0o755);
     }
   }
 
-  for (const binaryName of fs.readdirSync(distDir)) {
-    if (shouldGenerateShim(binaryName) === false)
+  for (const entry of fs.readdirSync(distDir, {withFileTypes: true})) {
+    if (entry.isDirectory())
       continue;
 
-    await cmdShim(path.join(distDir, binaryName), path.join(shimsDir, path.basename(binaryName, `.js`)), {createCmdFile: true});
+    await cmdShim(path.join(distDir, entry.name), path.join(shimsDir, path.basename(entry.name, `.js`)), {createCmdFile: true});
   }
 
   // The Node distribution doesn't support symlinks, so they copy the shims into
@@ -60,11 +62,11 @@ async function main() {
     stat: (p: string, cb: () => void) => fs.stat(remapPath(p), cb),
   });
 
-  for (const binaryName of fs.readdirSync(distDir)) {
-    if (shouldGenerateShim(binaryName) === false)
+  for (const entry of fs.readdirSync(distDir, {withFileTypes: true})) {
+    if (entry.isDirectory())
       continue;
 
-    await cmdShim(path.join(virtualNodewinDir, `dist/${binaryName}`), path.join(physicalNodewinDir, path.basename(binaryName, `.js`)), {createCmdFile: true, fs: easyStatFs});
+    await cmdShim(path.join(virtualNodewinDir, `dist/${entry.name}`), path.join(physicalNodewinDir, path.basename(entry.name, `.js`)), {createCmdFile: true, fs: easyStatFs});
   }
 
   console.log(`All shims have been generated.`);

package.json

@@ -51,8 +51,8 @@
   },
   "scripts": {
     "build": "rm -rf dist shims && run build:bundle && ts-node ./mkshims.ts",
-    "build:bundle": "esbuild ./sources/_entryPoint.ts --bundle --platform=node --target=node14.14.0 --external:corepack --outfile='./dist/corepack.js' --resolve-extensions='.ts,.mjs,.js'",
-    "corepack": "ts-node ./sources/_entryPoint.ts",
+    "build:bundle": "esbuild ./sources/_lib.ts --bundle --platform=node --target=node14.14.0 --external:corepack --outfile='./dist/lib/corepack.cjs' --resolve-extensions='.ts,.mjs,.js'",
+    "corepack": "ts-node ./sources/_cli.ts",
     "lint": "eslint .",
     "prepack": "yarn build",
     "postpack": "rm -rf dist shims",

sources/_cli.ts

@@ -0,0 +1,3 @@
+import {runMain} from './main';
+
+runMain(process.argv.slice(2));

sources/_entryPoint.ts

@@ -1,8 +0,0 @@
-#!/usr/bin/env node
-import {runMain} from './main';
-
-// Used by the generated shims
-export {runMain};
-
-if (process.mainModule === module)
-  runMain(process.argv.slice(2));

sources/_lib.ts

@@ -0,0 +1 @@
+export {runMain} from './main';