std/node: add some Node.js polyfill to require() (#3382)

1 files changed, 44 insertions, 0 deletions

diff --git a/std/node/module_test.ts b/std/node/module_test.ts
new file mode 100644
index 000000000..91744d94d
--- /dev/null
+++ b/std/node/module_test.ts
@@ -0,0 +1,44 @@
+import { test } from "../testing/mod.ts";
+import { assertEquals, assert } from "../testing/asserts.ts";
+import { createRequire } from "./module.ts";
+
+// TS compiler would try to resolve if function named "require"
+// Thus suffixing it with require_ to fix this...
+const require_ = createRequire(import.meta.url);
+
+test(function requireSuccess() {
+  // Relative to import.meta.url
+  const result = require_("./tests/cjs/cjs_a.js");
+  assert("helloA" in result);
+  assert("helloB" in result);
+  assert("C" in result);
+  assert("leftPad" in result);
+  assertEquals(result.helloA(), "A");
+  assertEquals(result.helloB(), "B");
+  assertEquals(result.C, "C");
+  assertEquals(result.leftPad("pad", 4), " pad");
+});
+
+test(function requireCycle() {
+  const resultA = require_("./tests/cjs/cjs_cycle_a");
+  const resultB = require_("./tests/cjs/cjs_cycle_b");
+  assert(resultA);
+  assert(resultB);
+});
+
+test(function requireBuiltin() {
+  const fs = require_("fs");
+  assert("readFileSync" in fs);
+  const { readFileSync, isNull, extname } = require_("./tests/cjs/cjs_builtin");
+  assertEquals(
+    readFileSync("./node/testdata/hello.txt", { encoding: "utf8" }),
+    "hello world"
+  );
+  assert(isNull(null));
+  assertEquals(extname("index.html"), ".html");
+});
+
+test(function requireIndexJS() {
+  const { isIndex } = require_("./tests/cjs");
+  assert(isIndex);
+});