Allow RCTBundleURLProvider to request an inline source map (#37878)

Summary:
See: http://blog.nparashuram.com/2019/10/debugging-react-native-ios-apps-with.html
When using direct debugging with JavaScriptCore, Safari Web Inspector doesn't pick up the source map over the network. Instead, as far as I can tell, it expects you to pass the source URL at the time you load your bundle:  https://developer.apple.com/documentation/javascriptcore/jscontext/1451384-evaluatescript?language=objc . This leads to a very sub-par developer experience debugging the JSbundle directly. It will however, pick up an inline source map. Therefore, let's add a way to have React Native tell metro to request an inline source map.

I did this by modifying `RCTBundleURLProvider` to have a new query parameter for `inlineSourceMap`, and set to true by default for JSC.

## Changelog:

[IOS] [ADDED] - Added support to inline the source map via RCTBundleURLProvider

Pull Request resolved: #37878

Test Plan:
I can put a breakpoint in RNTester, via Safari Web Inspector, in human readable code :D

<img width="1728" alt="Screenshot 2023-06-14 at 4 09 03 AM" src="https://github.com/facebook/react-native/assets/6722175/055277fa-d887-4566-9dc6-3ea07a1a60b0">

Reviewed By: motiz88

Differential Revision: D46855418

Pulled By: huntie

fbshipit-source-id: 2134cdbcd0a3e81052d26ed75f83601ae4ddecfe

Author: Saadnajmi

packages/react-native/React/Base/RCTBundleURLProvider.h

@@ -101,6 +101,7 @@ RCT_EXTERN void RCTBundleURLProviderAllowPackagerServerAccess(BOOL allowed);
 
 @property (nonatomic, assign) BOOL enableMinification;
 @property (nonatomic, assign) BOOL enableDev;
+@property (nonatomic, assign) BOOL inlineSourceMap;
 
 /**
  * The scheme/protocol used of the packager, the default is the http protocol
@@ -125,13 +126,32 @@ RCT_EXTERN void RCTBundleURLProviderAllowPackagerServerAccess(BOOL allowed);
 + (NSURL *)jsBundleURLForBundleRoot:(NSString *)bundleRoot
                        packagerHost:(NSString *)packagerHost
                           enableDev:(BOOL)enableDev
-                 enableMinification:(BOOL)enableMinification;
+                 enableMinification:(BOOL)enableMinification
+    __deprecated_msg(
+        "Use `jsBundleURLForBundleRoot:packagerHost:enableDev:enableMinification:inlineSourceMap:` instead");
+
++ (NSURL *)jsBundleURLForBundleRoot:(NSString *)bundleRoot
+                       packagerHost:(NSString *)packagerHost
+                     packagerScheme:(NSString *)scheme
+                          enableDev:(BOOL)enableDev
+                 enableMinification:(BOOL)enableMinification
+                        modulesOnly:(BOOL)modulesOnly
+                          runModule:(BOOL)runModule
+    __deprecated_msg(
+        "Use jsBundleURLForBundleRoot:packagerHost:enableDev:enableMinification:inlineSourceMap:modulesOnly:runModule:`  instead");
+
++ (NSURL *)jsBundleURLForBundleRoot:(NSString *)bundleRoot
+                       packagerHost:(NSString *)packagerHost
+                          enableDev:(BOOL)enableDev
+                 enableMinification:(BOOL)enableMinification
+                    inlineSourceMap:(BOOL)inlineSourceMap;
 
 + (NSURL *)jsBundleURLForBundleRoot:(NSString *)bundleRoot
                        packagerHost:(NSString *)packagerHost
                      packagerScheme:(NSString *)scheme
                           enableDev:(BOOL)enableDev
                  enableMinification:(BOOL)enableMinification
+                    inlineSourceMap:(BOOL)inlineSourceMap
                         modulesOnly:(BOOL)modulesOnly
                           runModule:(BOOL)runModule;
 /**
@@ -142,6 +162,17 @@ RCT_EXTERN void RCTBundleURLProviderAllowPackagerServerAccess(BOOL allowed);
 + (NSURL *)resourceURLForResourcePath:(NSString *)path
                          packagerHost:(NSString *)packagerHost
                                scheme:(NSString *)scheme
-                                query:(NSString *)query;
+                                query:(NSString *)query
+    __deprecated_msg("Use version with queryItems parameter instead");
+
+/**
+ * Given a hostname for the packager and a resource path (including "/"), return the URL to the resource.
+ * In general, please use the instance method to decide if the packager is running and fallback to the pre-packaged
+ * resource if it is not: -resourceURLForResourceRoot:resourceName:resourceExtension:offlineBundle:
+ */
++ (NSURL *)resourceURLForResourcePath:(NSString *)path
+                         packagerHost:(NSString *)packagerHost
+                               scheme:(NSString *)scheme
+                           queryItems:(NSArray<NSURLQueryItem *> *)queryItems;
 
 @end

packages/react-native/React/Base/RCTBundleURLProvider.mm

@@ -22,10 +22,12 @@ void RCTBundleURLProviderAllowPackagerServerAccess(BOOL allowed)
   kRCTAllowPackagerAccess = allowed;
 }
 #endif
+static NSString *const kRCTPlatformName = @"ios";
 static NSString *const kRCTPackagerSchemeKey = @"RCT_packager_scheme";
 static NSString *const kRCTJsLocationKey = @"RCT_jsLocation";
 static NSString *const kRCTEnableDevKey = @"RCT_enableDev";
 static NSString *const kRCTEnableMinificationKey = @"RCT_enableMinification";
+static NSString *const kRCTInlineSourceMapKey = @"RCT_inlineSourceMap";
 
 @implementation RCTBundleURLProvider
 
@@ -187,6 +189,7 @@ - (NSURL *)jsBundleURLForBundleRoot:(NSString *)bundleRoot fallbackURLProvider:(
                                            packagerScheme:[self packagerScheme]
                                                 enableDev:[self enableDev]
                                        enableMinification:[self enableMinification]
+                                          inlineSourceMap:[self inlineSourceMap]
                                               modulesOnly:NO
                                                 runModule:YES];
   }
@@ -199,6 +202,7 @@ - (NSURL *)jsBundleURLForSplitBundleRoot:(NSString *)bundleRoot
                                          packagerScheme:[self packagerScheme]
                                               enableDev:[self enableDev]
                                      enableMinification:[self enableMinification]
+                                        inlineSourceMap:[self inlineSourceMap]
                                             modulesOnly:YES
                                               runModule:NO];
 }
@@ -238,20 +242,37 @@ - (NSURL *)resourceURLForResourceRoot:(NSString *)root
   return [[self class] resourceURLForResourcePath:path
                                      packagerHost:packagerServerHostPort
                                            scheme:packagerServerScheme
-                                            query:nil];
+                                       queryItems:nil];
 }
 
 + (NSURL *)jsBundleURLForBundleRoot:(NSString *)bundleRoot
                        packagerHost:(NSString *)packagerHost
                           enableDev:(BOOL)enableDev
                  enableMinification:(BOOL)enableMinification
+{
+  return [self jsBundleURLForBundleRoot:bundleRoot
+                           packagerHost:packagerHost
+                         packagerScheme:nil
+                              enableDev:enableDev
+                     enableMinification:enableMinification
+                        inlineSourceMap:NO
+                            modulesOnly:NO
+                              runModule:YES];
+}
+
++ (NSURL *)jsBundleURLForBundleRoot:(NSString *)bundleRoot
+                       packagerHost:(NSString *)packagerHost
+                          enableDev:(BOOL)enableDev
+                 enableMinification:(BOOL)enableMinification
+                    inlineSourceMap:(BOOL)inlineSourceMap
 
 {
   return [self jsBundleURLForBundleRoot:bundleRoot
                            packagerHost:packagerHost
                          packagerScheme:nil
                               enableDev:enableDev
                      enableMinification:enableMinification
+                        inlineSourceMap:inlineSourceMap
                             modulesOnly:NO
                               runModule:YES];
 }
@@ -263,22 +284,43 @@ + (NSURL *)jsBundleURLForBundleRoot:(NSString *)bundleRoot
                  enableMinification:(BOOL)enableMinification
                         modulesOnly:(BOOL)modulesOnly
                           runModule:(BOOL)runModule
+{
+  return [self jsBundleURLForBundleRoot:bundleRoot
+                           packagerHost:packagerHost
+                         packagerScheme:nil
+                              enableDev:enableDev
+                     enableMinification:enableMinification
+                        inlineSourceMap:NO
+                            modulesOnly:modulesOnly
+                              runModule:runModule];
+}
+
++ (NSURL *)jsBundleURLForBundleRoot:(NSString *)bundleRoot
+                       packagerHost:(NSString *)packagerHost
+                     packagerScheme:(NSString *)scheme
+                          enableDev:(BOOL)enableDev
+                 enableMinification:(BOOL)enableMinification
+                    inlineSourceMap:(BOOL)inlineSourceMap
+                        modulesOnly:(BOOL)modulesOnly
+                          runModule:(BOOL)runModule
 {
   NSString *path = [NSString stringWithFormat:@"/%@.bundle", bundleRoot];
   BOOL lazy = enableDev;
-  // When we support only iOS 8 and above, use queryItems for a better API.
-  NSString *query = [NSString stringWithFormat:@"platform=ios&dev=%@&lazy=%@&minify=%@&modulesOnly=%@&runModule=%@",
-                                               enableDev ? @"true" : @"false",
-                                               lazy ? @"true" : @"false",
-                                               enableMinification ? @"true" : @"false",
-                                               modulesOnly ? @"true" : @"false",
-                                               runModule ? @"true" : @"false"];
+  NSArray<NSURLQueryItem *> *queryItems = @[
+    [[NSURLQueryItem alloc] initWithName:@"platform" value:kRCTPlatformName],
+    [[NSURLQueryItem alloc] initWithName:@"dev" value:enableDev ? @"true" : @"false"],
+    [[NSURLQueryItem alloc] initWithName:@"lazy" value:lazy ? @"true" : @"false"],
+    [[NSURLQueryItem alloc] initWithName:@"minify" value:enableMinification ? @"true" : @"false"],
+    [[NSURLQueryItem alloc] initWithName:@"inlineSourceMap" value:inlineSourceMap ? @"true" : @"false"],
+    [[NSURLQueryItem alloc] initWithName:@"modulesOnly" value:modulesOnly ? @"true" : @"false"],
+    [[NSURLQueryItem alloc] initWithName:@"runModule" value:runModule ? @"true" : @"false"],
+  ];
 
   NSString *bundleID = [[NSBundle mainBundle] objectForInfoDictionaryKey:(NSString *)kCFBundleIdentifierKey];
   if (bundleID) {
-    query = [NSString stringWithFormat:@"%@&app=%@", query, bundleID];
+    queryItems = [queryItems arrayByAddingObject:[[NSURLQueryItem alloc] initWithName:@"app" value:bundleID]];
   }
-  return [[self class] resourceURLForResourcePath:path packagerHost:packagerHost scheme:scheme query:query];
+  return [[self class] resourceURLForResourcePath:path packagerHost:packagerHost scheme:scheme queryItems:queryItems];
 }
 
 + (NSURL *)resourceURLForResourcePath:(NSString *)path
@@ -295,6 +337,20 @@ + (NSURL *)resourceURLForResourcePath:(NSString *)path
   return components.URL;
 }
 
++ (NSURL *)resourceURLForResourcePath:(NSString *)path
+                         packagerHost:(NSString *)packagerHost
+                               scheme:(NSString *)scheme
+                           queryItems:(NSArray<NSURLQueryItem *> *)queryItems
+{
+  NSURLComponents *components = [NSURLComponents componentsWithURL:serverRootWithHostPort(packagerHost, scheme)
+                                           resolvingAgainstBaseURL:NO];
+  components.path = path;
+  if (queryItems != nil) {
+    components.queryItems = queryItems;
+  }
+  return components.URL;
+}
+
 - (void)updateValue:(id)object forKey:(NSString *)key
 {
   [[NSUserDefaults standardUserDefaults] setObject:object forKey:key];
@@ -312,6 +368,11 @@ - (BOOL)enableMinification
   return [[NSUserDefaults standardUserDefaults] boolForKey:kRCTEnableMinificationKey];
 }
 
+- (BOOL)inlineSourceMap
+{
+  return [[NSUserDefaults standardUserDefaults] boolForKey:kRCTInlineSourceMapKey];
+}
+
 - (NSString *)jsLocation
 {
   return [[NSUserDefaults standardUserDefaults] stringForKey:kRCTJsLocationKey];
@@ -341,6 +402,11 @@ - (void)setEnableMinification:(BOOL)enableMinification
   [self updateValue:@(enableMinification) forKey:kRCTEnableMinificationKey];
 }
 
+- (void)setInlineSourceMap:(BOOL)inlineSourceMap
+{
+  [self updateValue:@(inlineSourceMap) forKey:kRCTInlineSourceMapKey];
+}
+
 - (void)setPackagerScheme:(NSString *)packagerScheme
 {
   [self updateValue:packagerScheme forKey:kRCTPackagerSchemeKey];

packages/rn-tester/RNTesterUnitTests/RCTBundleURLProviderTests.m

@@ -26,7 +26,7 @@
       URLWithString:
           [NSString
               stringWithFormat:
-                  @"http://localhost:8081/%@.bundle?platform=ios&dev=true&lazy=true&minify=false&modulesOnly=false&runModule=true&app=com.apple.dt.xctest.tool",
+                  @"http://localhost:8081/%@.bundle?platform=ios&dev=true&lazy=true&minify=false&inlineSourceMap=false&modulesOnly=false&runModule=true&app=com.apple.dt.xctest.tool",
                   testFile]];
 }
 
@@ -36,7 +36,7 @@
       URLWithString:
           [NSString
               stringWithFormat:
-                  @"http://192.168.1.1:8081/%@.bundle?platform=ios&dev=true&lazy=true&minify=false&modulesOnly=false&runModule=true&app=com.apple.dt.xctest.tool",
+                  @"http://192.168.1.1:8081/%@.bundle?platform=ios&dev=true&lazy=true&minify=false&inlineSourceMap=false&modulesOnly=false&runModule=true&app=com.apple.dt.xctest.tool",
                   testFile]];
 }