Scripts are sent in a non-existent `executionContextId`

Version

19.8.1

Platform

Darwin MacBook-Pro-2.guest.corp.microsoft.com 22.4.0 Darwin Kernel Version 22.4.0: Mon Mar 6 21:00:17 PST 2023; root:xnu-8796.101.5~3/RELEASE_X86_64 x86_64

Subsystem

inspector

What steps will reproduce the bug?

Run the following script:

const { Session } = require('node:inspector');

const session = new Session();
const executionContexts = new Map();
session.on('Runtime.executionContextCreated', call => {
  console.log(call);
  executionContexts.set(call.params.context.id, call.params.context);
});
session.on('Debugger.scriptParsed', call => {
  console.log(call);
  if (!executionContexts.has(call.params.executionContextId)) {
    console.error(`Got script in execution context ${call.params.executionContextId}, but have only ${[...executionContexts.keys()].join()}`);
    process.exit(1);
  }
});

session.connect();

session.post('Runtime.enable', () => {
  console.log('Runtime enabled')

  session.post('Debugger.enable', () => {
    console.log('Debugger enabled')
  });
});

How often does it reproduce? Is there a required condition?

100% of the time

What is the expected behavior? Why is that the expected behavior?

The script should run successfully. All execution contexts should come in Runtime.executionContextCreated events before Runtime.enable returns.

What do you see instead?

{
  method: 'Runtime.executionContextCreated',
  params: {
    context: {
      id: 1,
      origin: '',
      name: '/Users/connor/.asdf/installs/nodejs/19.8.1/bin/node[90017]',
      uniqueId: '-8333824095165494686.-3638729329792817601',
      auxData: [Object]
    }
  }
}
Runtime enabled
{
  method: 'Debugger.scriptParsed',
  params: {
    scriptId: '6',
    url: 'node:internal/per_context/primordials',
    startLine: 0,
    startColumn: 0,
    endLine: 737,
    endColumn: 0,
    executionContextId: 0,
    hash: 'bc07b5754e60d05f0e36aee626f46b4561cc1d342c7c84e1655eca736753f7f8',
    isLiveEdit: false,
    sourceMapURL: '',
    hasSourceURL: false,
    isModule: false,
    length: 21457,
    stackTrace: { callFrames: [Array] },
    scriptLanguage: 'JavaScript',
    embedderName: 'node:internal/per_context/primordials'
  }
}
Got script in execution context 0, but have only 1

Additional information

Later scripts are in the execution context ID of 1, but earlier ones are in the non-existent 0 context.

Originally came up in vscode-js-debug as a result of adding more intended correctness around how execution contexts are handled https://github.com/microsoft/vscode-js-debug/issues/1643

Start with the node:inspector Session entry point and run the reproduction script to observe Runtime.executionContextCreated and Debugger.scriptParsed ordering. Trace the inspector event handling involved in Runtime.enable and Debugger.enable; done means the reported script events use an existing execution context and the reproduction completes without exiting.