Re-enable test metrics

Both the durations and allocations will be _much_ higher with the new htmlRunner
which, for example, does 2 HTTP requests per test (html, testing.js).

#1057

Author: karlseguin

src/test_runner.zig

@@ -35,7 +35,7 @@ pub const std_options = std.Options{
 };
 
 pub var js_runner_duration: usize = 0;
-pub var tracking_allocator = TrackingAllocator.init(std.testing.allocator);
+pub var tracking_allocator: Allocator = undefined;
 
 pub fn main() !void {
     var mem: [8192]u8 = undefined;
@@ -52,6 +52,12 @@ pub fn main() !void {
     var args = try std.process.argsWithAllocator(allocator);
     defer args.deinit();
 
+    var tracking_arena = std.heap.ArenaAllocator.init(std.heap.c_allocator);
+    defer tracking_arena.deinit();
+
+    var ta = TrackingAllocator.init(tracking_arena.allocator());
+    tracking_allocator = ta.allocator();
+
     // ignore the exec name.
     _ = args.next();
     var json_stats = false;
@@ -82,6 +88,7 @@ pub fn main() !void {
         if (isSetup(t) or isTeardown(t)) {
             continue;
         }
+        defer _ = tracking_arena.reset(.retain_capacity);
 
         var status = Status.pass;
         slowest.startTiming();
@@ -175,7 +182,7 @@ pub fn main() !void {
     if (json_stats) {
         var stdout = std.fs.File.stdout();
         var writer = stdout.writer(&.{});
-        const stats = tracking_allocator.stats();
+        const stats = ta.stats();
         try std.json.Stringify.value(&.{
             .{ .name = "browser", .bench = .{
                 .duration = js_runner_duration,

src/testing.zig

@@ -360,8 +360,6 @@ fn isJsonValue(a: std.json.Value, b: std.json.Value) bool {
     }
 }
 
-pub const tracking_allocator = @import("root").tracking_allocator.allocator();
-
 var gpa: std.heap.GeneralPurposeAllocator(.{}) = .init;
 pub var test_app: *App = undefined;
 pub var test_browser: Browser = undefined;
@@ -387,9 +385,14 @@ pub fn shutdown() void {
 
 pub fn htmlRunner(file: []const u8) !void {
     defer _ = arena_instance.reset(.retain_capacity);
+
+    const start = try std.time.Instant.now();
+
     const page = try test_session.createPage();
     defer test_session.removePage();
 
+    page.arena = @import("root").tracking_allocator;
+
     const js_context = page.main_context;
     var try_catch: Env.TryCatch = undefined;
     try_catch.init(js_context);
@@ -399,6 +402,8 @@ pub fn htmlRunner(file: []const u8) !void {
     try page.navigate(url, .{});
     _ = page.wait(2000);
 
+    @import("root").js_runner_duration += std.time.Instant.since(try std.time.Instant.now(), start);
+
     const value = js_context.exec("testing.getStatus()", "testing.getStatus()") catch |err| {
         const msg = try_catch.err(arena_allocator) catch @errorName(err) orelse "unknown";
         std.debug.print("{s}: test failure\nError: {s}\n", .{ file, msg });