From b5bac20790b14f0033fbe3696fef3026eafcb3bb Mon Sep 17 00:00:00 2001
From: groenroos <oskari@groenroos.fi>
Date: Fri, 25 Feb 2022 05:40:15 +0000
Subject: [PATCH] #163: Implement options in Memory driver

---
 drivers/db/Memory.js           | 34 +++++++++++++++++++++++++++++++++-
 lib/Storage.js                 |  2 +-
 test/drivers/db/Memory.test.js | 29 +++++++++++++++++++++++++++++
 3 files changed, 63 insertions(+), 2 deletions(-)

diff --git a/drivers/db/Memory.js b/drivers/db/Memory.js
index e7b0867..2ed6e8b 100644
--- a/drivers/db/Memory.js
+++ b/drivers/db/Memory.js
@@ -59,8 +59,9 @@ export default class Memory extends Interface {
 	 *
 	 * @param {string} collection Name of the target collection
 	 * @param {object} conditions The search query
+	 * @param {object} options Options for the operation
 	 */
-	async read(collection, conditions) {
+	async read(collection, conditions, options) {
 		/* Fetch the collection, or provide an empty array if none exists */
 		let records = new Utils().deepClone(this.memory[collection] || []);
 
@@ -69,6 +70,37 @@ export default class Memory extends Interface {
 			records = records.filter(record => this.isMatch(record, conditions));
 		}
 
+		/* Limit and skip, if defined */
+		if (options && 'limit' in options) {
+			const skip = options.skip || 0;
+			records = records.slice(skip, options.limit + skip);
+		}
+
+		/* Sort, if defined */
+		if (options && 'sort' in options) {
+			records = records.sort((a, b) => {
+				let i = 0;
+				let result = 0;
+
+				/* Go through all sorted properties */
+				while (result === 0 && i < options.sort.length) {
+					const property = options.sort[i][0];
+
+					/* If property isn't available in record, forget about it */
+					if (!(property in a) || !(property in b)) {
+						continue;
+					}
+
+					/* Sort by property, in the direction requested */
+					result = (a[property] < b[property]) ? -1 : ((a[property] > b[property]) ? 1 : 0);
+					result *= options.sort[i][1];
+					i++;
+				}
+
+				return result;
+			});
+		}
+
 		return records;
 	}
 
diff --git a/lib/Storage.js b/lib/Storage.js
index 4bac61d..49adf21 100755
--- a/lib/Storage.js
+++ b/lib/Storage.js
@@ -267,7 +267,7 @@ export default class Storage {
 		const limit = (this.app.config.limit && this.app.config.limit > 0) ? this.app.config.limit : false;
 
 		/* Parse limit options */
-		if ('limit' in request.query) {
+		if ('limit' in request.query && Number(request.query.limit) !== 0) {
 			options.limit = Number(request.query.limit) || null;
 
 			/* If max limit is set in config, ensure we don't go over it */
diff --git a/test/drivers/db/Memory.test.js b/test/drivers/db/Memory.test.js
index dbb7205..2ba38b2 100644
--- a/test/drivers/db/Memory.test.js
+++ b/test/drivers/db/Memory.test.js
@@ -193,6 +193,35 @@ test.serial('reads nothing in a non-existent collection', async t => {
 	t.is(results.length, 0);
 });
 
+test.serial('limits records according to limit option', async t => {
+	const results = await t.context.memory.read('fifth', {}, { limit: 2 });
+
+	t.true(Array.isArray(results));
+	t.is(results.length, 2);
+});
+
+test.serial('skips records according to skip option', async t => {
+	const results = await t.context.memory.read('fifth', {}, { limit: 2, skip: 2 });
+
+	t.true(Array.isArray(results));
+	t.is(results.length, 2);
+	t.is(results[0].name, 'North Yorkshire');
+});
+
+test.serial('sorts records ascending according to sort option', async t => {
+	const results = await t.context.memory.read('fifth', {}, { sort: [ [ 'name', 1 ] ] });
+
+	t.true(Array.isArray(results));
+	t.is(results[0].name, 'Hamptons');
+});
+
+test.serial('sorts records descending according to sort option', async t => {
+	const results = await t.context.memory.read('fifth', {}, { sort: [ [ 'name', -1 ] ] });
+
+	t.true(Array.isArray(results));
+	t.is(results[0].name, 'North Yorkshire');
+});
+
 test.serial('modifies one record by ID', async t => {
 	const results = await t.context.memory.modify('first', { _id: t.context.memory.memory.first[0]._id }, { new: 'hello' });