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| const type = parts.find((part) => typeof part === 'object' && 'type' in part && part.type); | ||
| if (typeof type === 'string') { | ||
| options = { ...options, type }; | ||
| } |
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Bug: The parts.find() call returns a Blob object, but the subsequent check typeof type === 'string' expects a string, causing MIME type detection to always fail.
Severity: HIGH | Confidence: High
🔍 Detailed Analysis
The code attempts to automatically detect the MIME type from a Blob in the parts array. However, the parts.find() call returns the entire Blob object, which is assigned to the type variable. The subsequent condition if (typeof type === 'string') will always evaluate to false because type is an object, not a string. As a result, the intended MIME type is never extracted and applied to the File options, causing the automatic MIME type detection feature to silently fail. This can lead to files being sent with an incorrect Content-Type header.
💡 Suggested Fix
After finding the part containing the type, extract the type property from the object before the conditional check. For example: const foundPart = parts.find(...); const type = typeof foundPart === 'object' && 'type' in foundPart ? foundPart.type : undefined; if (typeof type === 'string') { ... }.
🤖 Prompt for AI Agent
Review the code at the location below. A potential bug has been identified by an AI
agent.
Verify if this is a real issue. If it is, propose a fix; if not, explain why it's not
valid.
Location: src/internal/to-file.ts#L113-L116
Potential issue: The code attempts to automatically detect the MIME type from a `Blob`
in the `parts` array. However, the `parts.find()` call returns the entire `Blob` object,
which is assigned to the `type` variable. The subsequent condition `if (typeof type ===
'string')` will always evaluate to false because `type` is an object, not a string. As a
result, the intended MIME type is never extracted and applied to the `File` options,
causing the automatic MIME type detection feature to silently fail. This can lead to
files being sent with an incorrect `Content-Type` header.
Did we get this right? 👍 / 👎 to inform future reviews.
Reference ID: 502265
Automated Release PR
0.1.0 (2025-12-30)
Full Changelog: v0.0.1...v0.1.0
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