FIXME: Handle Invalid Sequence

[aljones15]

bedrock-vc-exchanger/lib/exchangeInstance.js

Lines 139 to 191 in f7744c0

	export async function initializeTransaction({
	exchangeInstance, stepId, explain = false
	} = {}) {
	assert.object(exchangeInstance, 'exchangeInstance');
	assert.string(stepId, 'stepId');
	assert.bool(explain, 'explain');
	const exchangeInstanceId = decodeId({id: exchangeInstance.id});
	const transactionId = await generateId();
	const collection = database.collections[COLLECTION_NAME];
	const query = {
	'exchangeInstance.id': exchangeInstanceId,
	'exchangeInstance.sequence': exchangeInstance.sequence
	};
	const $inc = {
	'exchangeInstance.sequence': 1,
	};
	const $set = {
	'meta.updated': Date.now(),
	[`exchangeInstance.steps.${stepId}`]: {
	transactionId,
	data: null
	}
	};
	const options = {
	...database.writeOptions,
	// return document after the update
	returnDocument: 'after'
	};
	if(explain) {
	// 'find().limit(1)' is used here because 'updateOne()' doesn't return a
	// cursor which allows the use of the explain function.
	const cursor = await collection.find(query).limit(1);
	return cursor.explain('executionStats');
	}
	// FIXME: Handle exceptions due to invalid sequence
	const result = await collection.findOneAndUpdate(
	query, {$inc, $set}, options);
	if(!result.value) {
	// no document found, exchange instance invalid or expired
	throw new BedrockError(
	'Invalid or expired exchange instance.', 'DataError', {
	httpStatusCode: 400,
	public: true
	});
	}
	return transactionId;
	}

bedrock-vc-exchanger/lib/exchangeInstance.js

Lines 239 to 253 in f7744c0

	// FIXME: Handle exceptions due to invalid sequence
	const result = await collection.findOneAndUpdate(
	query, {$inc, $set}, options);
	if(!result.value) {
	// no document found, exchange instance invalid or expired
	throw new BedrockError(
	'Invalid or expired exchange instance.', 'DataError', {
	httpStatusCode: 400,
	public: true
	});
	}
	return result.value;
	}

Two functions need a pattern for handling invalid sequence numbers:

• storeResponseForExchangeStep
• initializeTransaction