fix(v4-sdk): update to use pathInput

[ericneil-sanc]

PR Scope

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Description

Uses pathInput for v4-sdk's midPrice() function, in the initial value of the reduce() call

How Has This Been Tested?

[e.g. Manually, E2E tests, unit tests, Storybook]

Are there any breaking changes?

[e.g. Type definitions, API definitions]

If there are breaking changes, please ensure you bump the major version Bump the major version (by using the title feat(breaking): ...), post a notice in #eng-sdks, and explicitly notify all Uniswap Labs consumers of the SDK.

(Optional) Feedback Focus

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(Optional) Follow Ups

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✨ Claude-Generated Content

Description

Fixes a bug in the Route.midPrice getter where this.input was incorrectly used instead of this.pathInput when determining the initial price direction in the reduce function.
The pathInput property contains the normalized currency that matches the pool's currencies (e.g., WETH), while input may be a native currency (e.g., ETH) that doesn't match the pool's currency0 or currency1. This caused incorrect price calculations when swapping native currencies through WETH pools.

Changes

• Updated midPrice getter in sdks/v4-sdk/src/entities/route.ts to use this.pathInput instead of this.input when comparing against this.pools[0].currency0 (line 80)
• Added unit tests for ETH input with WETH pool scenarios:
  • Single pool: ETH -> currency3 via WETH/currency3 pool
  • Multi-pool: ETH -> currency0 via WETH/currency3 and currency3/currency0 pools

How Has This Been Tested?

Unit tests added to verify midPrice calculations when using native currency (ETH) as input with WETH pools.

Are there any breaking changes?

No - this is a bug fix that corrects the price calculation behavior.

[github-actions]

🤖 Claude Code Review

✅ Review complete

Summary

This PR fixes a bug in the midPrice calculation for routes where the input currency is native (e.g., ETH) but the first pool uses the wrapped version (e.g., WETH).

The bug: In the midPrice getter, the initial accumulator compared this.pools[0].currency0 against this.input. When the input is ETH but the pool contains WETH, this comparison would fail to find a match, leading to incorrect price calculation direction.

The fix: Change the comparison from this.input to this.pathInput, which correctly represents the currency as it appears in the pool (WETH when ETH is provided and the pool uses WETH).

This is consistent with how the rest of the Route class works - pathInput is specifically designed to hold the "equivalent or wrapped/unwrapped input to match pool" as documented on line 17.

Verification

• All 24 route tests pass
• New tests added specifically cover the ETH → WETH pool scenario with both single and multi-pool routes
• The fix is minimal and targeted

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[github-actions]

📋 Review verdict: APPROVE

👆 The main review comment above is the source of truth for this PR review. It is automatically updated on each review cycle, so always refer to it for the most current feedback.

This formal review submission is for the verdict only.

Superseded by new review after PR update

[github-actions]

📋 Review verdict: APPROVE

👆 The main review comment above is the source of truth for this PR review. It is automatically updated on each review cycle, so always refer to it for the most current feedback.

This formal review submission is for the verdict only.

[graphite-app]

Graphite Automations

"Request reviewers once CI passes on sdks monorepo" took an action on this PR • (01/06/26)

2 reviewers were added and 1 assignee was added to this PR based on Siyu Jiang (See-You John)'s automation.

Superseded by new review after PR update

[github-actions]

📋 Review verdict: APPROVE

👆 The main review comment above is the source of truth for this PR review. It is automatically updated on each review cycle, so always refer to it for the most current feedback.

This formal review submission is for the verdict only.