WRNexusJS/packages/compiler/test/island-resolution.test.ts

import { expect, test } from "bun:test";
import { mkdirSync, mkdtempSync, writeFileSync } from "node:fs";
import { tmpdir } from "node:os";
import { join } from "node:path";
import { resolveWrnImport } from "../src/import-resolver.ts";

function appWith(files: Record<string, string>) {
  const root = mkdtempSync(join(tmpdir(), "wrnexus-island-"));
  mkdirSync(join(root, "app"), { recursive: true });
  for (const [name, contents] of Object.entries(files)) {
    writeFileSync(join(root, "app", name), contents);
  }
  return root;
}

test("resolves a .tsx import and tags it as an island", () => {
  const root = appWith({ "Chart.tsx": "export default function Chart() { return null; }" });
  const result = resolveWrnImport(
    { source: "./Chart", specifiers: [] } as any,
    join(root, "app", "page.wrn"),
    { appRoot: root },
  );

  expect(result.resolved).toContain("Chart.tsx");
  expect(result.kind).toBe("island");
});

test("does not tag a .ts import as an island", () => {
  const root = appWith({ "helper.ts": "export const value = 1;" });
  const result = resolveWrnImport(
    { source: "./helper", specifiers: [] } as any,
    join(root, "app", "page.wrn"),
    { appRoot: root },
  );

  expect(result.resolved).toContain("helper.ts");
  expect(result.kind).toBeUndefined();
});

test("prefers .wrn over .tsx when both exist", () => {
  const root = appWith({
    "Widget.wrn": "<template></template>",
    "Widget.tsx": "export default function Widget() { return null; }",
  });
  const result = resolveWrnImport(
    { source: "./Widget", specifiers: [] } as any,
    join(root, "app", "page.wrn"),
    { appRoot: root },
  );

  expect(result.resolved).toContain("Widget.wrn");
  expect(result.kind).toBeUndefined();
});

test("resolves an explicit .tsx extension as an island", () => {
  const root = appWith({ "Chart.tsx": "export default function Chart() { return null; }" });
  const result = resolveWrnImport(
    { source: "./Chart.tsx", specifiers: [] } as any,
    join(root, "app", "page.wrn"),
    { appRoot: root },
  );

  expect(result.kind).toBe("island");
});