Renamed fieldsArray file to FieldsArray

src/FieldsArray.ts

@@ -0,0 +1,82 @@
+import * as Schemas from "./schemas";
+import debug from "debug";
+
+const fieldsDebug = debug("passkit:fields");
+
+/**
+ * Class to represent lower-level keys pass fields
+ * @see https://apple.co/2wkUBdh
+ */
+
+const poolSymbol = Symbol("pool");
+
+export default class FieldsArray extends Array<Schemas.Field> {
+	private [poolSymbol]: Set<string>;
+
+	constructor(pool: Set<string>, ...args: Schemas.Field[]) {
+		super(...args);
+		this[poolSymbol] = pool;
+	}
+
+	/**
+	 * Like `Array.prototype.push` but will alter
+	 * also uniqueKeys set.
+	 */
+
+	push(...fieldsData: Schemas.Field[]): number {
+		const validFields = fieldsData.reduce(
+			(acc: Schemas.Field[], current: Schemas.Field) => {
+				try {
+					Schemas.assertValidity(Schemas.Field, current);
+				} catch (err) {
+					console.warn(`Cannot add field: ${err}`);
+					return acc;
+				}
+
+				if (this[poolSymbol].has(current.key)) {
+					console.warn(
+						`Cannot add field with key '${current.key}': another field already owns this key. Ignored.`,
+					);
+					return acc;
+				}
+
+				this[poolSymbol].add(current.key);
+				return [...acc, current];
+			},
+			[],
+		);
+
+		return super.push(...validFields);
+	}
+
+	/**
+	 * Like `Array.prototype.pop`, but will alter
+	 * also uniqueKeys set
+	 */
+
+	pop(): Schemas.Field {
+		const element: Schemas.Field = super.pop();
+		this[poolSymbol].delete(element.key);
+		return element;
+	}
+
+	/**
+	 * Like `Array.prototype.splice` but will alter
+	 * also uniqueKeys set
+	 */
+
+	splice(
+		start: number,
+		deleteCount: number,
+		...items: Schemas.Field[]
+	): Schemas.Field[] {
+		const removeList = this.slice(start, deleteCount + start);
+		removeList.forEach((item) => this[poolSymbol].delete(item.key));
+
+		return super.splice(start, deleteCount, ...items);
+	}
+
+	get length(): number {
+		return this.length;
+	}
+}