[fix]: make context.addInitScript() use correct isolated world

[seanmcguire12]

why

• currently, we add the init scripts to the main world
• this is problematic, because page.evaluate() uses the v3-world
• this means that you can't easily evaluate the script you add with addInitScript()

what changed

• makes sure that init scripts are added to the v3-world

test plan

• added a test which calls page.evaluate() on a script added via context.addInitScript()

[changeset-bot]

🦋 Changeset detected

Latest commit: 6d78851

The changes in this PR will be included in the next version bump.

This PR includes changesets to release 2 packages

Name	Type
@browserbasehq/stagehand	Patch
@browserbasehq/stagehand-evals	Patch

Not sure what this means? Click here to learn what changesets are.

Click here if you're a maintainer who wants to add another changeset to this PR

[greptile-apps]

Greptile Overview

Greptile Summary

Fixed context.addInitScript() to inject scripts into the v3-world isolated execution context instead of the main world, ensuring that page.evaluate() can access functions and globals added via init scripts.

Key changes:

• Modified installInitScriptOnSession() in packages/core/lib/v3/understudy/page.ts:135-138 to include worldName: "v3-world" parameter
• Added comprehensive test case verifying the fix works as expected
• Change is consistent with how other v3 components (Frame, selectorResolver) use isolated worlds throughout the codebase

Confidence Score: 5/5

• This PR is safe to merge with minimal risk
• The fix is a simple, targeted two-line change that correctly aligns init scripts with the isolated world pattern used throughout the v3 codebase. The change is well-tested with a new test case, follows existing patterns, and the implementation is correct
• No files require special attention

Important Files Changed

File Analysis

Filename	Score	Overview
packages/core/lib/v3/understudy/page.ts	5/5	Added worldName: "v3-world" to installInitScriptOnSession() to ensure init scripts execute in the same isolated world as page.evaluate(), making injected globals accessible
packages/core/lib/v3/tests/context-addInitScript.spec.ts	5/5	Added test verifying that functions injected via context.addInitScript() are callable from page.evaluate(), validating the isolated world fix
.changeset/seven-mice-draw.md	5/5	Changeset correctly describes the fix as a patch-level change with accurate user-facing description

Sequence Diagram

sequenceDiagram
    participant User
    participant Context
    participant Page
    participant CDPSession
    participant Browser
    participant IsolatedWorld as v3-world (Isolated)

    User->>Context: addInitScript(fn)
    Context->>Page: registerInitScript(source)
    Page->>Page: Check if script already exists
    Page->>Page: Add to initScripts array
    Page->>CDPSession: Page.addScriptToEvaluateOnNewDocument
    Note over CDPSession,Browser: worldName: "v3-world" (NEW)
    CDPSession->>Browser: Install script in v3-world
    Browser->>IsolatedWorld: Script registered for future docs
    
    User->>Page: goto(url)
    Browser->>IsolatedWorld: Execute init script in v3-world
    Note over IsolatedWorld: window.sayHelloFromStagehand = ...
    
    User->>Page: evaluate(fn)
    Page->>Page: createIsolatedWorldForCurrentMain()
    Note over Page,IsolatedWorld: Creates/reuses v3-world context
    Page->>IsolatedWorld: Runtime.evaluate in v3-world
    IsolatedWorld-->>Page: Access to init script globals
    Page-->>User: Result

Loading

[greptile-apps]

_{2 files reviewed, no comments}

_{Edit Code Review Agent Settings | Greptile}