Extract collection logic into separate utils - fixes #45 (#46)

source/index.ts

@@ -156,9 +156,11 @@ export interface Ow {
 
 const main = <T>(value: T, predicate: Predicate<T>) => {
 	for (const {validator, message} of predicate[validatorSymbol]) {
-		if (!validator(value)) {
+		const result = validator(value);
+
+		if (typeof result !== 'boolean' || !result) {
 			// TODO: Modify the stack output to show the original `ow()` call instead of this `throw` statement
-			throw new ArgumentError(message(value), main);
+			throw new ArgumentError(message(value, result), main);
 		}
 	}
 };

source/lib/predicates/map.ts

@@ -1,6 +1,7 @@
 import * as isEqual from 'lodash.isequal';
-import ow from '../..';
 import {Predicate, Context} from './predicate';
+import hasItems from '../utils/has-items';
+import ofType from '../utils/of-type';
 
 export class MapPredicate extends Predicate<Map<any, any>> {
 	constructor(context?: Context) {
@@ -49,25 +50,9 @@ export class MapPredicate extends Predicate<Map<any, any>> {
 	 * @param keys The keys that should be a key in the Map.
 	 */
 	hasKeys(...keys: any[]) {
-		const missingKeys: any[] = [];
-
 		return this.addValidator({
-			message: () => `Expected Map to have keys \`${JSON.stringify(missingKeys)}\``,
+			message: (_, missingKeys) => `Expected Map to have keys \`${JSON.stringify(missingKeys)}\``,
-			validator: map => {
+			validator: map => hasItems(map, keys)
-				for (const key of keys) {
-					if (map.has(key)) {
-						continue;
-					}
-
-					missingKeys.push(key);
-
-					if (missingKeys.length === 5) {
-						return false;
-					}
-				}
-
-				return missingKeys.length === 0;
-			}
 		});
 	}
 
@@ -89,27 +74,9 @@ export class MapPredicate extends Predicate<Map<any, any>> {
 	 * @param values The values that should be a value in the Map.
 	 */
 	hasValues(...values: any[]) {
-		const missingValues: any[] = [];
-
 		return this.addValidator({
-			message: () => `Expected Map to have values \`${JSON.stringify(missingValues)}\``,
+			message: (_, missingValues) => `Expected Map to have values \`${JSON.stringify(missingValues)}\``,
-			validator: map => {
+			validator: map => hasItems(new Set(map.values()), values)
-				const valueSet = new Set(map.values());
-
-				for (const value of values) {
-					if (valueSet.has(value)) {
-						continue;
-					}
-
-					missingValues.push(value);
-
-					if (missingValues.length === 5) {
-						return false;
-					}
-				}
-
-				return missingValues.length === 0;
-			}
 		});
 	}
 
@@ -135,23 +102,9 @@ export class MapPredicate extends Predicate<Map<any, any>> {
 	 * @param predicate The predicate that should be applied against every key in the Map.
 	 */
 	keysOfType<T>(predicate: Predicate<T>) {
-		let error: string;
-
 		return this.addValidator({
-			message: () => error,
+			message: (_, error) => error,
-			validator: map => {
+			validator: map => ofType(map.keys(), predicate)
-				try {
-					for (const item of map.keys()) {
-						ow(item, predicate);
-					}
-
-					return true;
-				} catch (err) {
-					error = err.message;
-
-					return false;
-				}
-			}
 		});
 	}
 
@@ -161,23 +114,9 @@ export class MapPredicate extends Predicate<Map<any, any>> {
 	 * @param predicate The predicate that should be applied against every value in the Map.
 	 */
 	valuesOfType<T>(predicate: Predicate<T>) {
-		let error: string;
-
 		return this.addValidator({
-			message: () => error,
+			message: (_, error) => error,
-			validator: map => {
+			validator: map => ofType(map.values(), predicate)
-				try {
-					for (const item of map.values()) {
-						ow(item, predicate);
-					}
-
-					return true;
-				} catch (err) {
-					error = err.message;
-
-					return false;
-				}
-			}
 		});
 	}
 

source/lib/predicates/predicate.ts

@@ -5,8 +5,8 @@ import {not} from '../operators/not';
  * @hidden
  */
 export interface Validator<T> {
-	message(value: T): string;
+	message(value: T, result?: any): string;
-	validator(value: T): boolean;
+	validator(value: T): any;
 }
 
 /**

source/lib/predicates/set.ts

@@ -1,6 +1,7 @@
 import * as isEqual from 'lodash.isequal';
-import ow from '../..';
 import {Predicate, Context} from './predicate';
+import hasItems from '../utils/has-items';
+import ofType from '../utils/of-type';
 
 export class SetPredicate extends Predicate<Set<any>> {
 	constructor(context?: Context) {
@@ -49,25 +50,9 @@ export class SetPredicate extends Predicate<Set<any>> {
 	 * @param items The items that should be a item in the Set.
 	 */
 	has(...items: any[]) {
-		const missingItems: any[] = [];
-
 		return this.addValidator({
-			message: () => `Expected Set to have items \`${JSON.stringify(missingItems)}\``,
+			message: (_, missingItems) => `Expected Set to have items \`${JSON.stringify(missingItems)}\``,
-			validator: set => {
+			validator: set => hasItems(set, items)
-				for (const item of items) {
-					if (set.has(item)) {
-						continue;
-					}
-
-					missingItems.push(item);
-
-					if (missingItems.length === 5) {
-						return false;
-					}
-				}
-
-				return missingItems.length === 0;
-			}
 		});
 	}
 
@@ -89,23 +74,9 @@ export class SetPredicate extends Predicate<Set<any>> {
 	 * @param predicate The predicate that should be applied against every item in the Set.
 	 */
 	ofType<T>(predicate: Predicate<T>) {
-		let error: string;
-
 		return this.addValidator({
-			message: () => error,
+			message: (_, error) => error,
-			validator: set => {
+			validator: set => ofType(set, predicate)
-				try {
-					for (const item of set.keys()) {
-						ow(item, predicate);
-					}
-
-					return true;
-				} catch (err) {
-					error = err.message;
-
-					return false;
-				}
-			}
 		});
 	}
 

source/lib/predicates/weak-map.ts

@@ -1,4 +1,5 @@
 import {Predicate, Context} from './predicate';
+import hasItems from '../utils/has-items';
 
 export class WeakMapPredicate extends Predicate<WeakMap<any, any>> {
 	constructor(context?: Context) {
@@ -11,25 +12,9 @@ export class WeakMapPredicate extends Predicate<WeakMap<any, any>> {
 	 * @param keys The keys that should be a key in the WeakMap.
 	 */
 	hasKeys(...keys: any[]) {
-		const missingKeys: any[] = [];
-
 		return this.addValidator({
-			message: () => `Expected WeakMap to have keys \`${JSON.stringify(missingKeys)}\``,
+			message: (_, missingKeys) => `Expected WeakMap to have keys \`${JSON.stringify(missingKeys)}\``,
-			validator: map => {
+			validator: map => hasItems(map, keys)
-				for (const key of keys) {
-					if (map.has(key)) {
-						continue;
-					}
-
-					missingKeys.push(key);
-
-					if (missingKeys.length === 5) {
-						return false;
-					}
-				}
-
-				return missingKeys.length === 0;
-			}
 		});
 	}
 

source/lib/predicates/weak-set.ts

@@ -1,4 +1,5 @@
 import {Predicate, Context} from './predicate';
+import hasItems from '../utils/has-items';
 
 export class WeakSetPredicate extends Predicate<WeakSet<any>> {
 	constructor(context?: Context) {
@@ -11,25 +12,9 @@ export class WeakSetPredicate extends Predicate<WeakSet<any>> {
 	 * @param items The items that should be a item in the WeakSet.
 	 */
 	has(...items: any[]) {
-		const missingItems: any[] = [];
-
 		return this.addValidator({
-			message: () => `Expected WeakSet to have items \`${JSON.stringify(missingItems)}\``,
+			message: (_, missingItems) => `Expected WeakSet to have items \`${JSON.stringify(missingItems)}\``,
-			validator: set => {
+			validator: set => hasItems(set, items)
-				for (const key of items) {
-					if (set.has(key)) {
-						continue;
-					}
-
-					missingItems.push(key);
-
-					if (missingItems.length === 5) {
-						return false;
-					}
-				}
-
-				return missingItems.length === 0;
-			}
 		});
 	}
 

source/lib/utils/has-items.ts

@@ -0,0 +1,27 @@
+type Collection = Set<any> | Map<any, any> | WeakSet<any> | WeakMap<any, any>;
+
+/**
+ * Retrieve the missing values in a collection based on an array of items.
+ *
+ * @hidden
+ * @param source Source collection to search through.
+ * @param items Items to search for.
+ * @param maxValues Maximum number of values after the search process is stopped. (Default: 5)
+ */
+export default (source: Collection, items: any[], maxValues = 5) => {
+	const missingValues: any[] = [];
+
+	for (const value of items) {
+		if (source.has(value)) {
+			continue;
+		}
+
+		missingValues.push(value);
+
+		if (missingValues.length === maxValues) {
+			return missingValues;
+		}
+	}
+
+	return missingValues.length === 0 ? true : missingValues;
+};

source/lib/utils/of-type.ts

@@ -0,0 +1,21 @@
+import ow from '../..';
+import {Predicate} from '../predicates/predicate';
+
+/**
+ * Test all the values in the collection against a provided predicate.
+ *
+ * @hidden
+ * @param source Source collection to test.
+ * @param predicate Predicate to test every item in the source collection against.
+ */
+export default (source: IterableIterator<any> | Set<any>, predicate: Predicate): boolean | string => {
+	try {
+		for (const item of source) {
+			ow(item, predicate);
+		}
+
+		return true;
+	} catch (err) {
+		return err.message;
+	}
+};