Python Test

1import { test } from "node:test";
2import assert from "node:assert/strict";
3import { resolvePythonCommand, pythonInvocation } from "./python.mjs";
4
5// Regression: on Windows a standard python.org install has no `python3.exe`
6// (only `python.exe` + the `py` launcher), so `spawn("python3", …)` ENOENTs and
7// every Python-backed audio feature silently no-ops. resolvePythonCommand takes
8// injectable platform/probe params so all branches are testable without
9// spawning a real interpreter.
10
11// probeFor(names): a probe that reports success only for the given argv-0 names.
12function probeFor(...names) {
13  const ok = new Set(names);
14  return (cmd) => ok.has(cmd);
15}
16
17test("non-win32 uses python3 when it runs", () => {
18  assert.deepEqual(resolvePythonCommand("linux", probeFor("python3")), ["python3"]);
19  assert.deepEqual(resolvePythonCommand("darwin", probeFor("python3")), ["python3"]);
20});
21
22test("win32 prefers python3 when the Microsoft Store build provides it", () => {
23  assert.deepEqual(resolvePythonCommand("win32", probeFor("python3", "python", "py")), ["python3"]);
24});
25
26test("win32 falls back to python.exe when python3 is absent (python.org install)", () => {
27  // The exact reported scenario: no python3, but `python` exists.
28  assert.deepEqual(resolvePythonCommand("win32", probeFor("python", "py")), ["python"]);
29});
30
31test("win32 falls back to the py launcher with -3 when only py exists", () => {
32  assert.deepEqual(resolvePythonCommand("win32", probeFor("py")), ["py", "-3"]);
33});
34
35test("py launcher is probed as `py -3 --version`, not bare `py`", () => {
36  const seen = [];
37  const probe = (cmd, args) => {
38    seen.push([cmd, ...args]);
39    return cmd === "py";
40  };
41  resolvePythonCommand("win32", probe);
42  assert.deepEqual(seen.at(-1), ["py", "-3", "--version"]);
43});
44
45test("falls back to the canonical name (loud failure, unchanged) when nothing runs", () => {
46  // No interpreter anywhere — must not throw, and must return python3 so the
47  // eventual spawn fails exactly as it did before this fix, never worse.
48  assert.deepEqual(
49    resolvePythonCommand("win32", () => false),
50    ["python3"],
51  );
52  assert.deepEqual(
53    resolvePythonCommand("linux", () => false),
54    ["python3"],
55  );
56});
57
58test("pythonInvocation prepends the resolved prefix ahead of caller args", () => {
59  assert.deepEqual(pythonInvocation(["-c", "import x"], ["python"]), {
60    cmd: "python",
61    args: ["-c", "import x"],
62  });
63  // The py launcher's -3 must stay ahead of the caller's own arguments.
64  assert.deepEqual(pythonInvocation(["-c", "import x"], ["py", "-3"]), {
65    cmd: "py",
66    args: ["-3", "-c", "import x"],
67  });
68});