Meta: Add a script to run the Web Platform tests locally

This change adds a script that can run the Web Platform Tests and
compare different test runs.

Documentation/RunningTests.md

@@ -67,3 +67,24 @@ cd Build/lagom
 ninja
 CTEST_OUTPUT_ON_FAILURE=1 LADYBIRD_SOURCE_DIR=${PWD}/../.. ninja test
 ```
+
+# Running the Web Platform Tests
+
+The Web Platform Tests can be run with the `WPT.sh` script. This script can also be used to compare the results of two 
+test runs.
+
+Example usage:
+
+```sh
+# Run the WPT tests then run them again, comparing the results from the two runs
+./Meta/WPT.sh run --log expectations.log css
+git checkout my-css-change
+./Meta/WPT.sh compare --log results.log expectations.log css
+```
+
+```sh
+# Pull the latest changes from the upstream WPT repository
+./Meta/WPT.sh update
+# Run all of the Web Platform Tests, outputting the results to results.log
+./Meta/WPT.sh run --log results.log 
+```

Meta/WPT.sh

@@ -0,0 +1,155 @@
+#!/usr/bin/env bash
+
+set -e
+
+DIR="$( cd "$( dirname "${BASH_SOURCE[0]}" )" && pwd )"
+
+LADYBIRD_SOURCE_DIR="$(realpath "${DIR}"/..)"
+WPT_SOURCE_DIR=${WPT_SOURCE_DIR:-"${LADYBIRD_SOURCE_DIR}/Tests/LibWeb/WPT/wpt"}
+WPT_REPOSITORY_URL=${WPT_REPOSITORY_URL:-"https://github.com/web-platform-tests/wpt.git"}
+
+LADYBIRD_BINARY=${LADYBIRD_BINARY:-"${LADYBIRD_SOURCE_DIR}/Build/ladybird/bin/Ladybird"}
+WEBDRIVER_BINARY=${WEBDRIVER_BINARY:-"${LADYBIRD_SOURCE_DIR}/Build/ladybird/bin/WebDriver"}
+
+WPT_PROCESSES=${WPT_PROCESSES:-$(nproc)}
+WPT_CERTIFICATES=(
+  "tools/certs/cacert.pem"
+  "${LADYBIRD_SOURCE_DIR}/Build/ladybird/Lagom/cacert.pem"
+)
+WPT_ARGS=( "--binary=${LADYBIRD_BINARY}"
+           "--webdriver-binary=${WEBDRIVER_BINARY}"
+           "--install-webdriver"
+            "--processes=${WPT_PROCESSES}"
+           "--webdriver-arg=--force-cpu-painting"
+            "--no-pause-after-test"
+           "-f"
+           "${EXTRA_WPT_ARGS[@]}"
+)
+
+ARG0=$0
+print_help() {
+  NAME=$(basename "$ARG0")
+  cat <<EOF
+  Usage: $NAME COMMAND [OPTIONS..] [TESTS...]
+    Supported COMMANDs:
+      update:     Update the Web Platform Tests repository.
+      run:        $NAME run [OPTIONS...] [TESTS...]
+                      Run the Web Platform Tests.
+      compare:    $NAME compare [OPTIONS...] LOG_FILE [TESTS...]
+                      Run the Web Platform Tests comparing the results to the expectations in LOG_FILE.
+
+    Examples:
+      $NAME update
+          Updates the Web Platform Tests repository.
+      $NAME run
+          Run all of the Web Platform Tests.
+      $NAME run --log expectations.log css dom
+          Run the Web Platform Tests in the 'css' and 'dom' directories and save the output to expectations.log.
+      $NAME compare expectations.log
+          Run all of the Web Platform Tests comparing the results to the expectations in before.log.
+      $NAME compare --log results.log expectations.log css/CSS2
+          Run the Web Platform Tests in the 'css/CSS2' directory, comparing the results to the expectations in expectations.log; output the results to results.log.
+EOF
+}
+
+usage() {
+    >&2 print_help
+    exit 1
+}
+
+CMD=$1
+[ -n "$CMD" ] || usage
+shift
+if [ "$CMD" = "--help" ] || [ "$CMD" = "help" ]; then
+    print_help
+    exit 0
+fi
+
+ARG=$1
+if [ "$ARG" = "--log" ]; then
+    shift
+    LOG_NAME="$(pwd -P)/$1"
+    [ -n "$LOG_NAME" ] || usage;
+    shift
+    WPT_ARGS+=( "--log-raw=${LOG_NAME}" )
+fi
+TEST_LIST=( "$@" )
+
+# shellcheck source=/dev/null
+. "${DIR}/shell_include.sh"
+
+exit_if_running_as_root "Do not run WPT.sh as root"
+
+ensure_wpt_repository() {
+    mkdir -p "${WPT_SOURCE_DIR}"
+    pushd "${WPT_SOURCE_DIR}" > /dev/null
+        if [ ! -d .git ]; then
+            git clone --depth 1 "${WPT_REPOSITORY_URL}" "${WPT_SOURCE_DIR}"
+        fi
+    popd > /dev/null
+}
+
+build_ladybird_and_webdriver() {
+    "${DIR}"/ladybird.sh build WebDriver
+}
+
+update_wpt() {
+    ensure_wpt_repository
+    pushd "${WPT_SOURCE_DIR}" > /dev/null
+        git pull
+    popd > /dev/null
+}
+
+execute_wpt() {
+    pushd "${WPT_SOURCE_DIR}" > /dev/null
+        for certificate_path in "${WPT_CERTIFICATES[@]}"; do
+            if [ ! -f "${certificate_path}" ]; then
+                echo "Certificate not found: \"${certificate_path}\""
+                exit 1
+            fi
+            WPT_ARGS+=( "--webdriver-arg=--certificate=${certificate_path}" )
+        done
+        QT_QPA_PLATFORM="minimal" ./wpt run "${WPT_ARGS[@]}" ladybird "${TEST_LIST[@]}"
+    popd > /dev/null
+}
+
+run_wpt() {
+    ensure_wpt_repository
+    build_ladybird_and_webdriver
+    execute_wpt
+}
+
+compare_wpt() {
+    ensure_wpt_repository
+    METADATA_DIR=$(mktemp -d)
+    pushd "${WPT_SOURCE_DIR}" > /dev/null
+      ./wpt update-expectations --product ladybird --full --metadata="${METADATA_DIR}" "${INPUT_LOG_NAME}"
+    popd > /dev/null
+    WPT_ARGS+=( "--metadata=${METADATA_DIR}" )
+    build_ladybird_and_webdriver
+    execute_wpt
+    rm -rf "${METADATA_DIR}"
+}
+
+if [[ "$CMD" =~ ^(update|run|compare)$ ]]; then
+    case "$CMD" in
+        update)
+            update_wpt
+            ;;
+        run)
+            run_wpt
+            ;;
+        compare)
+            INPUT_LOG_NAME="$(pwd -P)/$1"
+            if [ ! -f "$INPUT_LOG_NAME" ]; then
+                echo "Log file not found: \"${INPUT_LOG_NAME}\""
+                usage;
+            fi
+            shift
+            compare_wpt
+            ;;
+    esac
+else
+    >&2 echo "Unknown command: $CMD"
+    usage
+fi