Prepare repository for gradual flow->ts migration (#12317)

Co-authored-by: Bogdan Savluk <savluk.bogdan@gmail.com>

scripts/generators/tsconfig.js

@@ -0,0 +1,71 @@
+"use strict";
+
+const path = require("path");
+const fs = require("fs");
+
+const root = path.resolve(__dirname, "../../");
+
+const tsPkgs = fs
+  .readdirSync(path.join(root, "packages"))
+  .filter(name => name.startsWith("babel-"))
+  .map(name => ({
+    name: name.replace(/^babel-/, "@babel/"),
+    dir: path.resolve(root, "packages", name),
+  }))
+  .filter(({ dir }) => {
+    try {
+      fs.statSync(path.join(dir, "src", "index.ts"));
+      return true;
+    } catch {
+      return false;
+    }
+  });
+
+for (const { dir } of tsPkgs) {
+  const pkg = require(`${dir}/package.json`);
+
+  const references = [];
+  for (const dep of Object.keys(pkg.dependencies)) {
+    if (!dep.startsWith("@babel/")) continue;
+    for (const { name, dir: depDir } of tsPkgs) {
+      if (name === dep) {
+        references.push({ path: path.relative(dir, depDir) });
+        break;
+      }
+    }
+  }
+
+  fs.writeFileSync(
+    path.resolve(dir, "tsconfig.json"),
+    JSON.stringify(
+      {
+        extends: "../../tsconfig.base.json",
+        compilerOptions: {
+          // Until we have converted every package, we cannot store
+          // .d.ts files inside lib/ because it causes conflicts
+          // with Babel-related type definitions in node_modules/@types
+          outDir: "./dts",
+          rootDir: "./src",
+        },
+        include: ["./src/**/*"],
+        references,
+      },
+      null,
+      2
+    )
+  );
+}
+
+fs.writeFileSync(
+  path.resolve(root, `tsconfig.json`),
+  JSON.stringify(
+    {
+      files: [],
+      references: tsPkgs.map(({ dir }) => ({
+        path: path.relative(root, dir),
+      })),
+    },
+    null,
+    2
+  )
+);