test: add unresolved local import scanner

src/lib/local-imports.test.ts

@@ -0,0 +1,36 @@
+import { mkdtemp, mkdir, rm, writeFile } from "node:fs/promises";
+import { tmpdir } from "node:os";
+import { join } from "node:path";
+import { afterEach, describe, expect, it } from "vitest";
+import { findMissingLocalImports } from "./local-imports";
+
+const roots: string[] = [];
+
+afterEach(async () => {
+  await Promise.all(roots.splice(0).map((root) => rm(root, { recursive: true, force: true })));
+});
+
+describe("findMissingLocalImports", () => {
+  it("reports unresolved alias imports and ignores modules that exist", async () => {
+    const root = await mkdtemp(join(tmpdir(), "epicnext-imports-"));
+    roots.push(root);
+    await mkdir(join(root, "src", "features"), { recursive: true });
+    await mkdir(join(root, "src", "components", "ui"), { recursive: true });
+    await writeFile(join(root, "src", "components", "ui", "card.tsx"), "export const Card = {};\n");
+    await writeFile(
+      join(root, "src", "features", "page.tsx"),
+      [
+        'import { Card } from "@/components/ui/card";',
+        'import { Button } from "@/components/ui/button";',
+        "export default Card;",
+      ].join("\n"),
+    );
+
+    await expect(findMissingLocalImports(root)).resolves.toEqual([
+      {
+        importer: "src/features/page.tsx",
+        specifier: "@/components/ui/button",
+      },
+    ]);
+  });
+});

src/lib/local-imports.ts

@@ -0,0 +1,67 @@
+import { access, readdir, readFile } from "node:fs/promises";
+import { dirname, extname, join, relative, resolve, sep } from "node:path";
+
+export interface MissingLocalImport {
+  importer: string;
+  specifier: string;
+}
+
+const sourceExtensions = new Set([".ts", ".tsx", ".js", ".jsx", ".mjs", ".cjs"]);
+const resolutionSuffixes = [".ts", ".tsx", ".js", ".jsx", ".mjs", ".cjs", "/index.ts", "/index.tsx", "/index.js", "/index.jsx"];
+const importPattern = /(?:import|export)\s+(?:[^"']*?\s+from\s+)?["']([^"']+)["']|import\(\s*["']([^"']+)["']\s*\)|require\(\s*["']([^"']+)["']\s*\)/g;
+
+async function collectSourceFiles(directory: string): Promise<string[]> {
+  const entries = await readdir(directory, { withFileTypes: true });
+  const files = await Promise.all(
+    entries.map(async (entry) => {
+      const path = join(directory, entry.name);
+      if (entry.isDirectory()) return collectSourceFiles(path);
+      return sourceExtensions.has(extname(entry.name)) ? [path] : [];
+    }),
+  );
+  return files.flat();
+}
+
+async function exists(path: string): Promise<boolean> {
+  try {
+    await access(path);
+    return true;
+  } catch {
+    return false;
+  }
+}
+
+async function resolvesToLocalFile(base: string): Promise<boolean> {
+  if (sourceExtensions.has(extname(base)) && (await exists(base))) return true;
+  for (const suffix of resolutionSuffixes) {
+    if (await exists(`${base}${suffix}`)) return true;
+  }
+  return false;
+}
+
+export async function findMissingLocalImports(root: string): Promise<MissingLocalImport[]> {
+  const src = resolve(root, "src");
+  const files = await collectSourceFiles(src);
+  const missing: MissingLocalImport[] = [];
+
+  for (const importer of files) {
+    const source = await readFile(importer, "utf8");
+    for (const match of source.matchAll(importPattern)) {
+      const specifier = match[1] ?? match[2] ?? match[3];
+      if (!specifier?.startsWith("@/") && !specifier?.startsWith("./") && !specifier?.startsWith("../")) continue;
+      const base = specifier.startsWith("@/")
+        ? resolve(src, specifier.slice(2))
+        : resolve(dirname(importer), specifier);
+      if (!(await resolvesToLocalFile(base))) {
+        missing.push({
+          importer: relative(root, importer).split(sep).join("/"),
+          specifier,
+        });
+      }
+    }
+  }
+
+  return missing.sort((a, b) =>
+    a.importer.localeCompare(b.importer) || a.specifier.localeCompare(b.specifier),
+  );
+}