bring back std/examples/xeval.ts (#3822)

1 files changed, 48 insertions, 0 deletions

diff --git a/std/examples/tests/xeval_test.ts b/std/examples/tests/xeval_test.ts
new file mode 100644
index 000000000..db9cbceee
--- /dev/null
+++ b/std/examples/tests/xeval_test.ts
@@ -0,0 +1,48 @@
+import { xeval } from "../xeval.ts";
+import { stringsReader } from "../../io/util.ts";
+import { decode, encode } from "../../strings/mod.ts";
+import { assertEquals, assertStrContains } from "../../testing/asserts.ts";
+import { test } from "../../testing/mod.ts";
+const { execPath, run } = Deno;
+
+test(async function xevalSuccess(): Promise<void> {
+  const chunks: string[] = [];
+  await xeval(stringsReader("a\nb\nc"), ($): number => chunks.push($));
+  assertEquals(chunks, ["a", "b", "c"]);
+});
+
+test(async function xevalDelimiter(): Promise<void> {
+  const chunks: string[] = [];
+  await xeval(stringsReader("!MADMADAMADAM!"), ($): number => chunks.push($), {
+    delimiter: "MADAM"
+  });
+  assertEquals(chunks, ["!MAD", "ADAM!"]);
+});
+
+// https://github.com/denoland/deno/issues/2861
+const xevalPath = "examples/xeval.ts";
+
+test(async function xevalCliReplvar(): Promise<void> {
+  const p = run({
+    args: [execPath(), xevalPath, "--", "--replvar=abc", "console.log(abc)"],
+    stdin: "piped",
+    stdout: "piped",
+    stderr: "null"
+  });
+  await p.stdin!.write(encode("hello"));
+  await p.stdin!.close();
+  assertEquals(await p.status(), { code: 0, success: true });
+  assertEquals(decode(await p.output()).trimEnd(), "hello");
+});
+
+test(async function xevalCliSyntaxError(): Promise<void> {
+  const p = run({
+    args: [execPath(), xevalPath, "--", "("],
+    stdin: "null",
+    stdout: "piped",
+    stderr: "piped"
+  });
+  assertEquals(await p.status(), { code: 1, success: false });
+  assertEquals(decode(await p.output()), "");
+  assertStrContains(decode(await p.stderrOutput()), "Uncaught SyntaxError");
+});