Tests: Add LibWeb layout tests

Author: https://github.com/kalenikaliaksandr
Commit: 78b503946c
Pull-request: https://github.com/SerenityOS/serenity/pull/17230
Reviewed-by: https://github.com/linusg

Tests/LibWeb/Layout/layout_test.sh

@@ -0,0 +1,20 @@
+#!/usr/bin/env bash
+
+set -eo pipefail
+
+SCRIPT_DIR="$(dirname "${0}")"
+SERENITY_ROOT="$(realpath "${SCRIPT_DIR}"/../../..)"
+LADYBIRD_BUILD_DIR="${SERENITY_ROOT}/Build/ladybird"
+
+for filename in "$SCRIPT_DIR"/input/*; do
+    name=$(basename "$filename" .html)
+    input_html_path=$(realpath "$SCRIPT_DIR")/input/"$name".html
+    output_layout_dump=$(cd "$LADYBIRD_BUILD_DIR"; ./ladybird -d "$input_html_path")
+    expected_layout_dump_path="$(realpath "$SCRIPT_DIR")/expected/$name.txt"
+    if cmp <(echo "$output_layout_dump") "$expected_layout_dump_path"; then
+        echo "$name PASSED"
+    else
+        echo "$name FAILED"
+        diff "$expected_layout_dump_path" <(echo "$output_layout_dump")
+    fi
+done