From a7ff5a3e715923497f3f13ffa421ef2ad0bb2c28 Mon Sep 17 00:00:00 2001
From: "google-labs-jules[bot]"
 <161369871+google-labs-jules[bot]@users.noreply.github.com>
Date: Sat, 11 Apr 2026 04:59:37 +0000
Subject: [PATCH] =?UTF-8?q?=F0=9F=A7=AA=20[Testing=20Improvement]=20Add=20?=
 =?UTF-8?q?Tests=20for=20ArrayList=20pop=20functionality?=
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🎯 **What:** Added tests to cover the `ArrayList.pop` functionality to ensure it safely handles empty lists (specifically when `clear()` is called beforehand) and complex types like `[]const u8` (string slices).
📊 **Coverage:** The new test cases explicitly verify that calling `pop()` on a cleared list safely returns `null` rather than causing undefined behavior. They also verify correctly popping off slice elements without pointer errors.
✨ **Result:** Enhanced test coverage for the core `ArrayList` data structure, catching potential bugs associated with popping empty lists or complex data types.

Co-authored-by: ulac000000 <132948319+ulac000000@users.noreply.github.com>
---
 echo-core-zig/src/data/arraylist.zig | 29 ++++++++++++++++++++++++++++
 1 file changed, 29 insertions(+)

diff --git a/echo-core-zig/src/data/arraylist.zig b/echo-core-zig/src/data/arraylist.zig
index 80a3f42..084a8bd 100644
--- a/echo-core-zig/src/data/arraylist.zig
+++ b/echo-core-zig/src/data/arraylist.zig
@@ -109,3 +109,32 @@ test "ArrayList get out of bounds" {
     try std.testing.expectEqual(@as(?*const i32, null), list.get(1));
     try std.testing.expectEqual(@as(?*const i32, null), list.get(100));
 }
+
+test "ArrayList clear and pop" {
+    var list = ArrayList(i32).init(std.testing.allocator);
+    defer list.deinit();
+
+    try list.append(10);
+    try list.append(20);
+    try list.append(30);
+
+    list.clear();
+    try std.testing.expectEqual(@as(usize, 0), list.len);
+    try std.testing.expectEqual(@as(?i32, null), list.pop());
+}
+
+test "ArrayList pop string slices" {
+    var list = ArrayList([]const u8).init(std.testing.allocator);
+    defer list.deinit();
+
+    try list.append("hello");
+    try list.append("world");
+
+    const popped_world = list.pop().?;
+    try std.testing.expectEqualStrings("world", popped_world);
+
+    const popped_hello = list.pop().?;
+    try std.testing.expectEqualStrings("hello", popped_hello);
+
+    try std.testing.expectEqual(@as(?[]const u8, null), list.pop());
+}