Multi swap for custom paths

[MattPereira]

Overview

• We want to add support for swapping multiple tokens in a single tx
• This will only work for custom paths. The SOR does not support multi swap
• Currently this feature is prevented by the path validation below

b-sdk/src/entities/swap/paths/pathHelpers.ts

Lines 46 to 61 in 166466c

	const tokenIn = paths[0].tokens[0].address.toLowerCase();
	const tokenOut =
	paths[0].tokens[paths[0].tokens.length - 1].address.toLowerCase();
	if (
	!paths.every(
	(p) =>
	p.tokens[0].address.toLowerCase() === tokenIn &&
	p.tokens[p.tokens.length - 1].address.toLowerCase() ===
	tokenOut,
	)
	) {
	throw new Error(
	'Unsupported swap: all paths must start/end with same token.',
	);
	}
	}