storybookjs/storybook

[Bug]: CSF Parsing error: Expected 'ObjectExpression' but found 'undefined' instead in 'Identifier'.

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#31104 opened on Apr 12, 2025

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 (1 comment) (4 reactions) (0 assignees)TypeScript (89,909 stars) (10,058 forks)batch import
bugcsfhelp wanted

Description

Describe the bug

Image

Reproduction link

https://github.com/ianzone/storybook-init

Reproduction steps

clone, install and run dev, then see error in console.

System

System:
    OS: Linux 5.15 Ubuntu 24.04.2 LTS 24.04.2 LTS (Noble Numbat)
    CPU: (20) x64 13th Gen Intel(R) Core(TM) i7-13800H
    Shell: 5.9 - /home/linuxbrew/.linuxbrew/bin/zsh
  Binaries:
    Node: 22.14.0 - /home/linuxbrew/.linuxbrew/opt/node@22/bin/node
    Yarn: 1.22.22 - /home/linuxbrew/.linuxbrew/bin/yarn
    npm: 10.9.2 - /home/linuxbrew/.linuxbrew/opt/node@22/bin/npm
    pnpm: 10.8.0 - /home/linuxbrew/.linuxbrew/bin/pnpm
  npmPackages:
    @storybook/addon-a11y: ^8.6.11 => 8.6.11
    @storybook/addon-coverage: ^1.0.5 => 1.0.5
    @storybook/addon-essentials: ^8.6.11 => 8.6.11
    @storybook/addon-interactions: ^8.6.11 => 8.6.11
    @storybook/addon-links: ^8.6.11 => 8.6.11
    @storybook/blocks: ^8.6.11 => 8.6.11
    storybook: ^8.6.11 => 8.6.11
    storybook-addon-rslib: ^1.0.1 => 1.0.1
    storybook-react-rsbuild: ^1.0.1 => 1.0.1

Additional context

No response

Contributor guide

Tech stack
typescriptjavascriptreactnodejs
Domain
frontendtoolingdeveloper experience
Issue type
bug
DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.
3
Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.
1-3 hours
Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.
fresh
ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.
clear
Prerequisites
JavaScriptStorybook basics
Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.
60
Research direction
The bug is in CSF parsing, likely in the storybook core. Start by reproducing the issue using the provided repo. Search the codebase for the error string 'Expected ObjectExpression but found undefined instead' to locate the relevant parser. Check the packages that handle CSF (e.g., @storybook/core server, @storybook/csf tools). Look at recent commits that might have introduced a regression. The reproduction uses storybook react rsbuild, so also examine the integration with rsbuild.