Telemetry: Remove instance of check for sub-error handling

[valentinpalkovic]

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What I did

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  • bug: Internal changes that fixes incorrect behavior.
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Summary by CodeRabbit

Release Notes

• Bug Fixes
  • Improved error telemetry to capture more complete diagnostic data from nested error scenarios, enabling better error tracking and system monitoring without affecting user experience.

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☁️ Nx Cloud last updated this comment at 2025-12-14 11:19:49 UTC

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☁️ Nx Cloud last updated this comment at 2025-12-14 11:19:01 UTC

[coderabbitai]

📝 Walkthrough

Walkthrough

Modifies error handling in telemetry to use a permissive runtime check for subErrors presence instead of strict type checking. Iterates through subErrors unconditionally and invokes sendTelemetryError on each, passing the original error as parent context, removing inner type guards.

Changes

Cohort / File(s)	Summary
Telemetry error handling code/core/src/core-server/withTelemetry.ts	Replaces strict StorybookError type check with permissive runtime check for subErrors property; iterates subErrors unconditionally and sends telemetry for each, allowing non-StorybookError sub-errors to be processed under the same parent context

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10–15 minutes

• Focus areas: Understand the rationale for removing the strict type guard and verify the permissive runtime check handles edge cases appropriately (e.g., errors with undefined or empty subErrors).

Possibly related PRs

• storybookjs/storybook#33295: Modifies the same withTelemetry.ts file to iterate and propagate StorybookError subErrors for separate telemetry event emission.

✨ Finishing touches

• 📝 Generate docstrings

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[coderabbitai]

Actionable comments posted: 1

📜 Review details

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Review profile: CHILL

Plan: Pro

📥 Commits

Reviewing files that changed from the base of the PR and between c4980c1 and d8169b5.

📒 Files selected for processing (1)

• code/core/src/core-server/withTelemetry.ts (1 hunks)

🧰 Additional context used

📓 Path-based instructions (5)

**/*.{js,jsx,json,html,ts,tsx,mjs}

📄 CodeRabbit inference engine (.github/copilot-instructions.md)

Use ESLint and Prettier configurations that are enforced in the codebase

Files:

• code/core/src/core-server/withTelemetry.ts

**/*.{ts,tsx}

📄 CodeRabbit inference engine (.github/copilot-instructions.md)

Enable TypeScript strict mode

Files:

• code/core/src/core-server/withTelemetry.ts

code/**/*.{ts,tsx,js,jsx,mjs}

📄 CodeRabbit inference engine (.github/copilot-instructions.md)

code/**/*.{ts,tsx,js,jsx,mjs}: Use server-side logger from 'storybook/internal/node-logger' for Node.js code
Use client-side logger from 'storybook/internal/client-logger' for browser code
Do not use console.log, console.warn, or console.error directly unless in isolated files where importing loggers would significantly increase bundle size

Files:

• code/core/src/core-server/withTelemetry.ts

code/**/*.{ts,tsx,js,jsx}

📄 CodeRabbit inference engine (.github/copilot-instructions.md)

Export functions that need to be tested from their modules

Files:

• code/core/src/core-server/withTelemetry.ts

code/**/*.{js,jsx,json,html,ts,tsx,mjs}

📄 CodeRabbit inference engine (.github/copilot-instructions.md)

code/**/*.{js,jsx,json,html,ts,tsx,mjs}: Run Prettier with --write flag to format code before committing
Run ESLint with yarn lint:js:cmd to check for linting issues and fix errors before committing

Files:

• code/core/src/core-server/withTelemetry.ts

🧠 Learnings (1)

📚 Learning: 2025-11-05T09:37:25.920Z

Learnt from: Sidnioulz
Repo: storybookjs/storybook PR: 32458
File: code/core/src/components/components/tooltip/WithTooltip.tsx:54-96
Timestamp: 2025-11-05T09:37:25.920Z
Learning: Repo: storybookjs/storybook — In code/core/src/components/components/tooltip/WithTooltip.tsx, the legacy WithTooltip implementation is intentionally reintroduced for backward compatibility and is deprecated; maintainers (per Sidnioulz) do not want maintenance or improvements on it. Prefer WithTooltipNew/Popover; avoid suggesting changes to WithTooltip.* going forward.

Applied to files:

• code/core/src/core-server/withTelemetry.ts

🧬 Code graph analysis (1)

code/core/src/core-server/withTelemetry.ts (1)

code/core/src/server-errors.ts (1)

• StorybookError (8-8)

⏰ Context from checks skipped due to timeout of 90000ms. You can increase the timeout in your CodeRabbit configuration to a maximum of 15 minutes (900000ms). (6)

• GitHub Check: normal
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• GitHub Check: Core Unit Tests, windows-latest
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[coderabbitai]

⚠️ Potential issue | 🟠 Major

Add defensive checks to prevent runtime errors with non-StorybookError objects.

The change replaces strict type checking with duck-typing ('subErrors' in error), which introduces several type safety risks:

1. No array validation: error.subErrors.length assumes subErrors is an array, but the in operator only checks property existence. If a non-array subErrors property exists, this will throw at runtime.

2. Unsafe cast to StorybookError: Line 142 casts error as StorybookError without verification. When this reaches line 130, parent.fullErrorCode may be undefined if the error lacks this property.

3. Missing structural validation: Each subError is passed recursively without verifying it matches the expected error structure.

While the try-catch block prevents crashes, it may mask legitimate issues and make debugging harder.

Consider adding defensive runtime checks:

-      if (error && 'subErrors' in error && error.subErrors.length > 0) {
+      if (
+        error &&
+        'subErrors' in error &&
+        Array.isArray(error.subErrors) &&
+        error.subErrors.length > 0 &&
+        'fullErrorCode' in error
+      ) {
         for (const subError of error.subErrors) {
           await sendTelemetryError(subError, eventType, options, blocking, error as StorybookError);
         }
       }

Alternatively, verify this change is intentional and document why duck-typing is preferred over instanceof StorybookError.