changes after CR

packages/vscode-extension/lib/metro_helpers.js

@@ -41,14 +41,17 @@ function adaptMetroConfig(config) {
         module.output[0].data.code = `${preludeCode};var __REACT_DEVTOOLS_PORT__=${process.env.RCT_DEVTOOLS_PORT};`;
       }
     } else if (module.path === "__env__") {
-      // this handles @expo/env plugin, which is used to expose the number of lines in the prelude. 
-      // This is used to calculate the line number offset when reporting line numbers for 
-      // console.logs, breakpoints and uncaught exceptions. The reason why this is needed, is that
+      // this handles @expo/env plugin, which is used to inject environment variables
+      // the code below instantiates a global variable __EXPO_ENV_PRELUDE_LINES__ that stores
+      // the number of lines in the prelude. This is used to calculate the line number offset
+      // when reporting line numbers from the JS runtime, breakpoints
+      // and uncaught exceptions. The reason why this is needed, is that
       // metro doesn't include __env__ prelude in the source map resulting in the source map
       // transformation getting shifted by the number of lines in the prelude.
-      const expoEnvPreludeLines = module.output[0].data.lineCount;
-      process.stdout.write(JSON.stringify({ type: "RNIDE_Expo_Env_Prelude_Lines", expoEnvPreludeLines }));
-      process.stdout.write("\n");      
+      const expoEnvCode = module.output[0].data.code;
+      if (!expoEnvCode.includes("__EXPO_ENV_PRELUDE_LINES__")) {
+        module.output[0].data.code = `${expoEnvCode};var __EXPO_ENV_PRELUDE_LINES__=${module.output[0].data.lineCount};`;
+      }
     }
     return origProcessModuleFilter(module);
   };

packages/vscode-extension/src/debugging/DebugAdapter.ts

@@ -86,8 +86,6 @@ export class DebugAdapter extends DebugSession {
   private projectPathAlias?: string;
   private threads: Array<Thread> = [];
   private sourceMaps: Array<[string, string, SourceMapConsumer, number]> = [];
-  private lineOffset: number;
-
   private linesStartAt1 = true;
   private columnsStartAt1 = true;
 
@@ -99,7 +97,6 @@ export class DebugAdapter extends DebugSession {
     this.absoluteProjectPath = configuration.absoluteProjectPath;
     this.projectPathAlias = configuration.projectPathAlias;
     this.connection = new WebSocket(configuration.websocketAddress);
-    this.lineOffset = configuration.lineOffset;
 
     this.connection.on("open", () => {
       // the below catch handler is used to ignore errors coming from non critical CDP messages we
@@ -155,6 +152,10 @@ export class DebugAdapter extends DebugSession {
             const sourceMap = JSON.parse(decodedData);
             const consumer = await new SourceMapConsumer(sourceMap);
 
+            const sourceFile = await (await fetch(message.params.url)).text();
+            const lineOffsetRegex = /__EXPO_ENV_PRELUDE_LINES__=(\d+);/;
+            const match = sourceFile.match(lineOffsetRegex);
+            const lineOffset = Number(match ? match[1] : null);
             // This line is here because of a problem with sourcemaps for expo projects,
             // that was addressed in this PR https://github.com/expo/expo/pull/29463,
             // unfortunately it still requires changes to metro that were attempted here
@@ -164,11 +165,13 @@ export class DebugAdapter extends DebugSession {
             // (generated during reload) do not contain the prelude causing the issue
             const shouldApplyOffset =
               semver.lte(getReactNativeVersion(), "0.76.0") && this.sourceMaps.length === 0;
+            Logger.debug("Expo prelude lines were detected and an offset was set to:", lineOffset);
+
             this.sourceMaps.push([
               message.params.url,
               message.params.scriptId,
               consumer,
-              shouldApplyOffset ? this.lineOffset : 0,
+              shouldApplyOffset ? lineOffset : 0,
             ]);
             this.updateBreakpointsInSource(message.params.url, consumer);
           }

packages/vscode-extension/src/debugging/DebugSession.ts

@@ -56,7 +56,6 @@ export class DebugSession implements Disposable {
         websocketAddress: websocketAddress,
         absoluteProjectPath: getAppRootFolder(),
         projectPathAlias: this.metro.isUsingNewDebugger ? "/[metro-project]" : undefined,
-        lineOffset: this.metro.initialBundleLineOffset,
       },
       {
         suppressDebugStatusbar: true,

packages/vscode-extension/src/project/metro.ts

@@ -46,10 +46,6 @@ type MetroEvent =
       transformedFileCount: number;
       totalFileCount: number;
     }
-  | {
-      type: "RNIDE_Expo_Env_Prelude_Lines";
-      expoEnvPreludeLines: number;
-    }
   | {
       type: "RNIDE_initialize_done";
       port: number;
@@ -68,7 +64,6 @@ type MetroEvent =
 export class Metro implements Disposable {
   private subprocess?: ChildProcess;
   private _port = 0;
-  private _initialBundleLineOffset = 0;
   private startPromise: Promise<void> | undefined;
   private usesNewDebugger?: Boolean;
 
@@ -85,10 +80,6 @@ export class Metro implements Disposable {
     return this._port;
   }
 
-  public get initialBundleLineOffset() {
-    return this._initialBundleLineOffset;
-  }
-
   public dispose() {
     this.subprocess?.kill(9);
   }
@@ -216,12 +207,6 @@ export class Metro implements Disposable {
           }
 
           switch (event.type) {
-            case "RNIDE_Expo_Env_Prelude_Lines":
-              this._initialBundleLineOffset = event.expoEnvPreludeLines;
-              Logger.debug(
-                `Metro initial bundle offset is set to ${this._initialBundleLineOffset}`
-              );
-              break;
             case "RNIDE_initialize_done":
               this._port = event.port;
               Logger.info(`Metro started on port ${this._port}`);