Added array support to delta calculations

package.json

@@ -1,6 +1,6 @@
 {
 	"name": "@ztimson/utils",
-	"version": "0.26.21",
+	"version": "0.26.26",
 	"description": "Utility library",
 	"author": "Zak Timson",
 	"license": "MIT",

src/database.ts

@@ -100,9 +100,9 @@ export class Database {
 			if(!this.includes(table.name)) {
 				const newDb = new Database(this.database, [...this.tables, table], (this.version ?? 0) + 1);
 				conn.close();
-				await newDb.connection;
-				Object.assign(this, newDb);
+				this.connection = newDb.connection;
 				await this.connection;
+				Object.assign(this, newDb);
 			}
 			return this.table<K, T>(table.name);
 		});
@@ -115,9 +115,9 @@ export class Database {
 			const conn = await this.connection;
 			const newDb = new Database(this.database, this.tables.filter(t => t.name != (<TableOptions>table).name), (this.version ?? 0) + 1);
 			conn.close();
-			await newDb.connection;
-			Object.assign(this, newDb);
+			this.connection = newDb.connection;
 			await this.connection;
+			Object.assign(this, newDb);
 		});
 	}
 

src/misc.ts

@@ -1,9 +1,21 @@
 import {PathEvent} from './path-events.ts';
 import {md5} from './string';
 
+/**
+ * Compare version numbers
+ * @param {string} target
+ * @param {string} vs
+ * @return {number} -1 = target is lower, 0 = equal, 1 = higher
+ */
+export function compareVersions(target: string, vs: string): -1 | 0 | 1 {
+	const [tMajor, tMinor, tPatch] = target.split('.').map(v => +v.replace(/[^0-9]/g, ''));
+	const [vMajor, vMinor, vPatch] = vs.split('.').map(v => +v.replace(/[^0-9]/g, ''));
+	return (tMajor > vMajor || tMinor > vMinor || tPatch > vPatch) ? 1 :
+		(tMajor < vMajor || tMinor < vMinor || tPatch < vPatch) ? -1 : 0;
+}
+
 /**
  * Escape any regex special characters to avoid misinterpretation during search
- *
  * @param {string} value String which should be escaped
  * @return {string} New escaped sequence
  */

src/objects.ts

@@ -1,3 +1,58 @@
+export type Delta = { [key: string]: any | Delta | null };
+
+/**
+ * Applies deltas in order to modify `target`.
+ * @param target - Object to mutate
+ * @param deltas - List of deltas to apply
+ * @returns Mutated target
+ */
+export function applyDeltas(target: any, deltas: Delta[]): any {
+	for(const delta of deltas) {
+		for(const [key, value] of Object.entries(delta)) {
+			if(value === null) {
+				delete target[key]; // Remove
+			} else if(Array.isArray(value)) {
+				target[key] = [...value]; // Array
+			} else if(typeof value === 'object') {
+				if(typeof target[key] !== 'object' || Array.isArray(target[key]) || !target[key])
+					target[key] = {}; // Nested
+				applyDeltas(target[key], [value]); // Recurse
+			} else {
+				target[key] = value; // Primitive
+			}
+		}
+	}
+	return target;
+}
+
+/**
+ * Creates a nested delta that reverts `target` back to `old`.
+ * @param old - Original object
+ * @param target - Modified object
+ * @returns Delta to revert changes
+ */
+export function calcDelta(old: any, target: any): Delta {
+	const delta: Delta = {};
+	const keys = new Set([...Object.keys(old || {}), ...Object.keys(target || {})]);
+	for(const key of keys) {
+		const val1 = old?.[key];
+		const val2 = target?.[key];
+		if(!(key in target)) {
+			delta[key] = val1; // Removed
+		} else if(!(key in old)) {
+			delta[key] = null; // Added
+		} else if(Array.isArray(val1) || Array.isArray(val2)) {
+			if(JSON.stringify(val1) !== JSON.stringify(val2)) delta[key] = val1; // Array
+		} else if(typeof val1 === 'object' && typeof val2 === 'object' && val1 && val2) {
+			const nested = calcDelta(val1, val2);
+			if(Object.keys(nested).length) delta[key] = nested; // Nested
+		} else if(val1 !== val2) {
+			delta[key] = val1; // Modified
+		}
+	}
+	return delta;
+}
+
 /**
  * Removes any null values from an object in-place
  *