Add argument parser unit coverage

tests/args.test.mjs

@@ -0,0 +1,67 @@
+import assert from "node:assert/strict";
+import test from "node:test";
+
+import { parseArgs, splitRawArgumentString } from "../plugins/codex/scripts/lib/args.mjs";
+
+const config = {
+  valueOptions: ["base", "scope"],
+  booleanOptions: ["wait", "background"],
+  aliasMap: { b: "base", w: "wait" }
+};
+
+test("parseArgs handles separate and inline long-option values", () => {
+  assert.deepEqual(parseArgs(["--base", "main", "--scope=branch", "focus"], config), {
+    options: { base: "main", scope: "branch" },
+    positionals: ["focus"]
+  });
+});
+
+test("parseArgs handles boolean values and short aliases", () => {
+  assert.deepEqual(parseArgs(["-w", "--background=false", "-b", "trunk"], config), {
+    options: { wait: true, background: false, base: "trunk" },
+    positionals: []
+  });
+});
+
+test("parseArgs preserves unknown options as positionals", () => {
+  assert.deepEqual(parseArgs(["--unknown=value", "-x", "-"], config), {
+    options: {},
+    positionals: ["--unknown=value", "-x", "-"]
+  });
+});
+
+test("parseArgs treats every token after -- as positional", () => {
+  assert.deepEqual(parseArgs(["--wait", "--", "--base", "main"], config), {
+    options: { wait: true },
+    positionals: ["--base", "main"]
+  });
+});
+
+test("parseArgs rejects missing long-option values", () => {
+  assert.throws(() => parseArgs(["--base"], config), /Missing value for --base/);
+});
+
+test("parseArgs rejects missing short-option values", () => {
+  assert.throws(() => parseArgs(["-b"], config), /Missing value for -b/);
+});
+
+test("splitRawArgumentString groups single- and double-quoted text", () => {
+  assert.deepEqual(splitRawArgumentString(`review "two words" 'single quoted' plain`), [
+    "review",
+    "two words",
+    "single quoted",
+    "plain"
+  ]);
+});
+
+test("splitRawArgumentString handles escaped spaces, quotes, and backslashes", () => {
+  assert.deepEqual(splitRawArgumentString(String.raw`one\ two \"quoted\" path\\tail`), [
+    "one two",
+    '"quoted"',
+    "path\\tail"
+  ]);
+});
+
+test("splitRawArgumentString preserves a trailing backslash", () => {
+  assert.deepEqual(splitRawArgumentString("value\\"), ["value\\"]);
+});