MetaMask / MetaMask/metamask-extension

[Bug]: Swap - Autoselected quote with 99% price impact instead of selecting quotes with 0% price impact when swapping mUSD

Open
#43,093 2 comments 0 reactions 0 assignees View on GitHub

Nobody has claimed this yet.

regression-RC-13.34.0 Sev2-normal team-swaps-and-bridge type-bug
Dominant language
TypeScript
Stars
13.2k
Forks
5.6k
Avg merge
2d 5h
Merged PRs (30d)
451

Description

### Describe the bug

Autoselected quote with 99% price impact instead of selecting quotes with 0% price impact.
This leads to loose all the assets in the Swap if proceed.
This seems to happen when Swapping from stable coin mUSD to regular asset (ie ETH)

### Expected behavior

We shouldn't autoselect 99% price impact quotes, if there are others which has almost 0% price impact

### Screenshots/Recordings

https://github.com/user-attachments/assets/bf5fd18f-df44-4e93-9e77-6714daa3a65c

### Steps to reproduce

1. Click Swap
2. Select source token mUSD
3. Select destination token ETH
4. Add any amount
5. See selected quote has very high price impact, whereas other quotes in the list have no price impact

### Error messages or log output

```shell

```

### Where was this bug found?

Internal release testing

### Version

13.34.0

### Build type

None

### Browser

Chrome

### Operating system

MacOS

### Hardware wallet

_No response_

### Additional context

_No response_

### Severity

_No response_

Contributor guide

Open the contributing guide

First steps

  1. Read the whole issue, then the project's contributing guide.
  2. Comment on the issue to say you are picking it up — it saves two people doing the same work.
  3. Fork the repository and make your change on a branch.
  4. Open a pull request that references the issue number.

Research direction

Start by reproducing the Swap flow in Chrome with mUSD as the source token and ETH as the destination, using version 13.34.0, then inspect the quote-selection entry point. Confirm the fix by ensuring the autoselected quote does not have 99% price impact when another available quote is near 0%.

Written by the indexing model from the issue text.

Assessment

Tech stack
typescript
Domain
blockchain, frontend
Issue type
Bug
Difficulty
4/5
Estimated time
3-5 days
Activity status
Quiet
Clarity
Mostly clear
Newbie friendliness
45/100

Get new issues in your inbox

A short digest of beginner-friendly GitHub issues.