feat(codex): auto-install git bash via winget on windows

packages/omo-codex/scripts/install/git-bash.test.mjs

@@ -1,7 +1,7 @@
 import assert from "node:assert/strict";
 import test from "node:test";
 
-import { resolveGitBash } from "./git-bash.mjs";
+import { prepareGitBashForInstall, resolveGitBash } from "./git-bash.mjs";
 
 const programFilesGitBash = "C:\\Program Files\\Git\\bin\\bash.exe";
 const programFilesX86GitBash = "C:\\Program Files (x86)\\Git\\bin\\bash.exe";
@@ -68,3 +68,63 @@ test("#given Windows without Git Bash #when resolving #then returns install guid
 	assert.match(result.installHint, /winget install --id Git\.Git -e --source winget/);
 	assert.match(result.installHint, /rerun `bunx omo install --platform=codex`/);
 });
+
+test("#given Windows without Git Bash and winget is allowed #when preparing #then winget runs and resolver retries", async () => {
+	const runCalls = [];
+	const resolutions = [
+		{ found: false, checkedPaths: [programFilesGitBash], installHint: "install hint" },
+		{ found: true, path: programFilesGitBash, source: "program-files" },
+	];
+	let resolveCallCount = 0;
+
+	const result = await prepareGitBashForInstall({
+		platform: "win32",
+		env: {},
+		cwd: "C:\\repo",
+		resolveGitBash: () => resolutions[resolveCallCount++] ?? resolutions[resolutions.length - 1],
+		runCommand: async (command, args, options) => {
+			runCalls.push([command, ...args, options.cwd].join(" "));
+		},
+	});
+
+	assert.deepEqual(runCalls, ["winget install --id Git.Git -e --source winget C:\\repo"]);
+	assert.equal(resolveCallCount, 2);
+	assert.deepEqual(result, { found: true, path: programFilesGitBash, source: "program-files" });
+});
+
+test("#given Windows without Git Bash and skip env is set #when preparing #then winget is not run and install hint remains", async () => {
+	const runCalls = [];
+	const missingResolution = {
+		found: false,
+		checkedPaths: [programFilesGitBash, programFilesX86GitBash],
+		installHint: "install hint",
+	};
+
+	const result = await prepareGitBashForInstall({
+		platform: "win32",
+		env: { OMO_CODEX_SKIP_GIT_BASH_AUTO_INSTALL: "1" },
+		cwd: "C:\\repo",
+		resolveGitBash: () => missingResolution,
+		runCommand: async (command, args, options) => {
+			runCalls.push([command, ...args, options.cwd].join(" "));
+		},
+	});
+
+	assert.deepEqual(runCalls, []);
+	assert.deepEqual(result, missingResolution);
+});
+
+test("#given non-Windows platform #when preparing #then winget is never called", async () => {
+	const runCalls = [];
+	const result = await prepareGitBashForInstall({
+		platform: "linux",
+		env: {},
+		cwd: "/repo",
+		runCommand: async (command, args, options) => {
+			runCalls.push([command, ...args, options.cwd].join(" "));
+		},
+	});
+
+	assert.deepEqual(runCalls, []);
+	assert.deepEqual(result, { found: true, path: null, source: "not-required" });
+});