feat: added custom tx builder for sol

[raj-bitgo]

• added custom instruction builder for sol
• use new intent type solInstruction to build the tx in WP

TICKET: TMS-1218

[zahin-mohammad]

Some concerns here, moving this to slack

[sachushaji]

We should throw an error for this case?

[raj-bitgo]

Yeah, good catch. Added an assertion check

[sachushaji]

We can move this utilities in a dedicated util file?

[raj-bitgo]

moved

[sachushaji]

@claude review this pr

[Copilot]

Pull Request Overview

This PR adds custom instruction builder functionality for Solana to support arbitrary instruction execution. It introduces a new intent type solInstruction that allows users to build transactions with custom Solana instructions without being limited to predefined instruction types.

• Adds new solInstruction intent type and transaction handling logic across the SDK
• Implements custom instruction builder and factory methods for processing arbitrary Solana instructions
• Updates type definitions and validation to support string-based instruction format for TSS compatibility

Reviewed Changes

Copilot reviewed 16 out of 16 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
modules/sdk-core/src/bitgo/wallet/wallet.ts	Adds handling for solInstruction transaction type in prebuild flow
modules/sdk-core/src/bitgo/wallet/iWallet.ts	Adds solInstructions option to prebuild transaction parameters
modules/sdk-core/src/bitgo/wallet/BuildParams.ts	Adds solInstructions parameter to build params validation
modules/sdk-core/src/bitgo/utils/tss/baseTypes.ts	Adds solInstructions type definitions for TSS operations
modules/sdk-core/src/bitgo/utils/mpcUtils.ts	Adds validation for solInstruction intent type
modules/sdk-core/src/account-lib/baseCoin/enum.ts	Adds new SolanaCustomInstructions transaction type
modules/sdk-coin-sol/src/sol.ts	Implements coin-specific intent field handling for Solana instructions
modules/sdk-coin-sol/src/lib/utils.ts	Adds validation utilities for base64 and hex string formats
modules/sdk-coin-sol/src/lib/transaction.ts	Updates transaction handling for custom instruction type
modules/sdk-coin-sol/src/lib/solInstructionFactory.ts	Converts string-based instruction format to TransactionInstruction objects
modules/sdk-coin-sol/src/lib/instructionParamsFactory.ts	Adds parsing logic for custom instructions
modules/sdk-coin-sol/src/lib/iface.ts	Updates CustomInstruction interface to use string-based format
modules/sdk-coin-sol/src/lib/customInstructionBuilder.ts	Refactors builder to accept string-based instruction format with validation
modules/sdk-coin-sol/test/unit/transactionBuilder/customInstructionBuilder.ts	Updates tests to use new string-based instruction format
modules/sdk-coin-sol/test/unit/solInstructionFactory.ts	Adds comprehensive tests for TSS format instruction handling
modules/bitgo/test/v2/unit/wallet.ts	Adds test coverage for solInstruction transaction flow

Comments suppressed due to low confidence (1)

modules/sdk-core/src/bitgo/utils/mpcUtils.ts:128

• The intent type 'customInstructions' is added to the validation list but the actual intent type used elsewhere is 'solInstruction'. This inconsistency could cause validation to fail.

      !['acceleration', 'fillNonce', 'transferToken', 'tokenApproval', 'customInstructions'].includes(params.intentType)

[Copilot]

The regex allows empty strings to be considered valid hex, but an empty string has length 0 which satisfies the even length condition. This could lead to unexpected behavior when processing empty data strings.

Suggested change

	return /^[0-9A-Fa-f]*$/.test(str) && str.length % 2 === 0;
	return str.length > 0 && /^[0-9A-Fa-f]*$/.test(str) && str.length % 2 === 0;

[Phani024]

👍

[Copilot]

The data conversion logic tries base64 first, then hex, then UTF-8. However, some valid hex strings might also be valid base64, leading to incorrect interpretation. Consider adding explicit format indicators or more strict validation.

Suggested change

	// Convert string data to Buffer
	let dataBuffer: Buffer;
	if (isValidBase64(params.data)) {
	dataBuffer = Buffer.from(params.data, 'base64');
	} else if (isValidHex(params.data)) {
	dataBuffer = Buffer.from(params.data, 'hex');
	} else {
	// Fallback to UTF-8
	dataBuffer = Buffer.from(params.data, 'utf8');
	assert(params.dataFormat === 'base64' || params.dataFormat === 'hex' || params.dataFormat === 'utf8', 'Missing or invalid dataFormat in custom instruction');
	// Convert string data to Buffer using explicit format
	let dataBuffer: Buffer;
	switch (params.dataFormat) {
	case 'base64':
	assert(isValidBase64(params.data), 'data is not valid base64');
	dataBuffer = Buffer.from(params.data, 'base64');
	break;
	case 'hex':
	assert(isValidHex(params.data), 'data is not valid hex');
	dataBuffer = Buffer.from(params.data, 'hex');
	break;
	case 'utf8':
	dataBuffer = Buffer.from(params.data, 'utf8');
	break;
	default:
	throw new Error('Unsupported dataFormat in custom instruction');