From 9dfcb9ec3ae6987a3231e4d6dd2bf8fb557440c8 Mon Sep 17 00:00:00 2001
From: Moti Zilberman <moti@meta.com>
Date: Tue, 21 May 2024 15:17:34 -0700
Subject: [PATCH] Generate object previews for live console messages

Summary:
Changelog: [Internal]

bypass-github-export-checks

Currently, Hermes never generates object/array previews for values logged via the `console` API. This makes console logs significantly less readable than in Chrome. Here we enable the preview generation machinery that already exists in Hermes.

We conservatively mimic V8's behaviour of [only generating previews for immediately-emitted messages](https://source.chromium.org/chromium/chromium/src/+/main:v8/src/inspector/v8-console-agent-impl.cc;l=53,64;drc=451a101b0a8bbc323dbf5697dd956b55284ec9ee) and not for buffered messages. I don't know *why* V8 does this, but can only guess it's meant to improve the performance of starting a debugging session, by evaluating less code and sending smaller payloads. (Anyway, we can change our decision later.)

Reviewed By: dannysu

Differential Revision: D57617059

fbshipit-source-id: 1f5a71ce98ac915a5b874ed6c009d971405a9f2d
---
 .../tests/ConsoleApiTest.cpp                  | 39 +++++++++++++++++++
 1 file changed, 39 insertions(+)

diff --git a/packages/react-native/ReactCommon/jsinspector-modern/tests/ConsoleApiTest.cpp b/packages/react-native/ReactCommon/jsinspector-modern/tests/ConsoleApiTest.cpp
index 1dec6c86d4c..5cf43e44842 100644
--- a/packages/react-native/ReactCommon/jsinspector-modern/tests/ConsoleApiTest.cpp
+++ b/packages/react-native/ReactCommon/jsinspector-modern/tests/ConsoleApiTest.cpp
@@ -84,6 +84,10 @@ class ConsoleApiTest
     JsiIntegrationPortableTest::TearDown();
   }
 
+  /**
+   * Expect a console API call to be reported with parameters matching \param
+   * paramsMatcher.
+   */
   void expectConsoleApiCall(Matcher<folly::dynamic> paramsMatcher) {
     if (runtimeEnabled_) {
       expectConsoleApiCallImpl(std::move(paramsMatcher));
@@ -92,6 +96,28 @@ class ConsoleApiTest
     }
   }
 
+  /**
+   * Expect a console API call to be reported with parameters matching \param
+   * paramsMatcher, only if the Runtime domain is currently enabled ( = the call
+   * is reported in real time).
+   */
+  void expectConsoleApiCallImmediate(Matcher<folly::dynamic> paramsMatcher) {
+    if (runtimeEnabled_) {
+      expectConsoleApiCallImpl(std::move(paramsMatcher));
+    }
+  }
+
+  /**
+   * Expect a console API call to be reported with parameters matching \param
+   * paramsMatcher, only if the Runtime domain is currently disabled ( = the
+   * call will be buffered and reported later upon enabling the domain).
+   */
+  void expectConsoleApiCallBuffered(Matcher<folly::dynamic> paramsMatcher) {
+    if (!runtimeEnabled_) {
+      expectedConsoleApiCalls_.emplace_back(paramsMatcher);
+    }
+  }
+
   bool isRuntimeDomainEnabled() const {
     return runtimeEnabled_;
   }
@@ -758,6 +784,19 @@ TEST_P(ConsoleApiTest, testConsoleLogTwice) {
   eval("console.log('hello again');");
 }
 
+TEST_P(ConsoleApiTest, testConsoleLogWithObjectPreview) {
+  InSequence s;
+  expectConsoleApiCallImmediate(AllOf(
+      AtJsonPtr("/type", "log"),
+      AtJsonPtr("/args/0/preview/type", "object"),
+      AtJsonPtr("/args/0/preview/overflow", false),
+      AtJsonPtr("/args/0/preview/properties/0/name", "string"),
+      AtJsonPtr("/args/0/preview/properties/0/type", "string"),
+      AtJsonPtr("/args/0/preview/properties/0/value", "hello")));
+  expectConsoleApiCallBuffered(AllOf(AtJsonPtr("/type", "log")));
+  eval("console.log({ string: 'hello' });");
+}
+
 static const auto paramValues = testing::Values(
     Params{
         .withConsolePolyfill = true,