fix(tui): detect Apple Terminal Shift+Enter

packages/tui/test/terminal.test.ts

@@ -1,6 +1,45 @@
 import assert from "node:assert";
 import { describe, it } from "node:test";
-import { ProcessTerminal } from "../src/terminal.ts";
+import { isNativeModifierPressed } from "../src/native-modifiers.ts";
+import { normalizeAppleTerminalInput, ProcessTerminal } from "../src/terminal.ts";
+
+function withEnv(name: string, value: string | undefined, fn: () => void): void {
+	const previous = process.env[name];
+	if (value === undefined) delete process.env[name];
+	else process.env[name] = value;
+	try {
+		fn();
+	} finally {
+		if (previous === undefined) delete process.env[name];
+		else process.env[name] = previous;
+	}
+}
+
+describe("normalizeAppleTerminalInput", () => {
+	it("rewrites Apple Terminal Return to CSI-u Shift+Enter when Shift is pressed", () => {
+		assert.equal(normalizeAppleTerminalInput("\r", true, true), "\x1b[13;2u");
+	});
+
+	it("leaves Apple Terminal Return unchanged when Shift is not pressed", () => {
+		assert.equal(normalizeAppleTerminalInput("\r", true, false), "\r");
+	});
+
+	it("leaves non-Apple Terminal Return unchanged when Shift is pressed", () => {
+		assert.equal(normalizeAppleTerminalInput("\r", false, true), "\r");
+	});
+
+	it("leaves non-Return input unchanged", () => {
+		assert.equal(normalizeAppleTerminalInput("\x1b[13;2u", true, true), "\x1b[13;2u");
+		assert.equal(normalizeAppleTerminalInput("a", true, true), "a");
+	});
+
+	it("treats native helper failure as Shift not pressed", () => {
+		withEnv("PI_TUI_DISABLE_NATIVE_MODIFIERS", "1", () => {
+			assert.equal(isNativeModifierPressed("shift"), false);
+			assert.equal(normalizeAppleTerminalInput("\r", true, isNativeModifierPressed("shift")), "\r");
+		});
+	});
+});
 
 describe("ProcessTerminal dimensions", () => {
 	it("falls back to COLUMNS and LINES before default dimensions", () => {