feat: Removed quicksort for stable sorting

src/core/expression.spec.ts

@@ -4,19 +4,19 @@ import { createPredicate } from './expression';
 describe.concurrent('#createPredicate()', () => {
  it('test1', () => {
  const expr = createPredicate<string>(null);
- expect(expr()).toBeFalsy();
+ expect(expr('a')).toBeFalsy();
  });
  it('test2', () => {
  const expr1 = createPredicate<string>(true);
- expect(expr1()).toBeTruthy();
+ expect(expr1('a')).toBeTruthy();
 
  const expr2 = createPredicate<string>(false);
- expect(expr2()).toBeFalsy();
+ expect(expr2('a')).toBeFalsy();
  });
  it('test3', () => {
  const expr1 = createPredicate<string>(() => true);
  const expr2 = createPredicate(expr1);
- expect(expr2()).toBeTruthy();
+ expect(expr2('a')).toBeTruthy();
  });
 });
 

src/core/expression.ts

@@ -60,9 +60,9 @@ function createExpression<T>(predicate: Predicate<T>): Expression<T> {
 * @param expression - Default expression, could be a boolean indicating the default return value
 * @returns The started expression
 */
-export function createPredicate<T = any>(expression?: boolean): Expression<T>;
-export function createPredicate<T = any>(expression?: Predicate<T>): Expression<T>;
-export function createPredicate<T = any>(expression?: Predicate<T>|boolean): Expression<T> {
+export function createPredicate<T>(expression?: boolean|null): Expression<T>;
+export function createPredicate<T>(expression?: Predicate<T>): Expression<T>;
+export function createPredicate<T>(expression?: Predicate<T>|boolean): Expression<T> {
  let current = typeof expression == 'function'
  ? createExpression(expression)
  : null;

src/core/index.ts

@@ -1,5 +1,4 @@
 export * from './enumerator';
 export * from './expression';
-export * from './quicksort';
 export * from './types';
 export * from './utils';

src/core/types.ts

@@ -11,7 +11,7 @@ export type Operation<T = unknown, TRes = T> = Pipe<Enumerable<T>, Enumerable<TR
 export type Collector<T = unknown, TRes = unknown> = Pipe<Enumerable<T>, TRes>;
 
 export interface Predicate<T = unknown> {
- (value?: T, index?: number): boolean
+ (value: T, index?: number): boolean
 }
 
 export type Accumulator<T, TAcc, TResult = unknown> = (acc: TAcc, value: T, index: number) => TResult;

src/core/utils.ts

@@ -1,4 +1,3 @@
-import { quicksort } from './quicksort';
 import { Comparison, Enumerable, Grouping, OrderedEnumerable, Pipe, Key } from './types';
 
 /**
@@ -31,6 +30,30 @@ export function deepEqual<
  return (Object.keys(b).length == keys.length) && keys.every(key => deepEqual(a[key], b[key]));
 }
 
+/**
+ * Shim to ensure stable sorting in pre ES2019 browser engines, as sorting is unstable
+ * @param source - Input iterable to sort
+ * @param comparisons - Array of comparison functions to use in the sorting, at least one is required
+ * @returns A copy of the array, but sorted
+ * @internal
+ */
+function stableSort<T>(source: Enumerable<T>, comparers: Comparison<T>[]): T[] {
+ // Sort with comparer functions chained into each other if the previous one returns 0
+ const list = [ ...source ];
+
+ return list.sort((x, y) => {
+ for (let idx = 0; idx < comparers.length; idx++) {
+ const res = comparers[idx](x, y);
+
+ if (res !== 0) {
+ return res;
+ }
+ }
+
+ return list.indexOf(x) - list.indexOf(y);
+ });
+}
+
 /**
  * 
  * @param source 
@@ -45,9 +68,9 @@ export function createOrderedEnumerable<T>(comparer: Comparison<T>): Pipe<Enumer
  return Object.create({
  comparers,
  [Symbol.iterator]() {
- const sorter = quicksort(source, ...comparers);
- 
- return sorter[Symbol.iterator]();
+ const sorted = stableSort(source, comparers);
+
+ return sorted[Symbol.iterator]();
  },
  });
  };

src/order/__snapshots__/orderByDescending.spec.ts.snap

@@ -2,18 +2,18 @@
 
 exports[`#orderByDescending() > test1 1`] = `
 [
- {
- "carbs": 49,
- "fat": 16,
- "name": "Gingerbread",
- "prot": 0,
- },
  {
  "carbs": 24,
  "fat": 16,
  "name": "Eclair",
  "prot": 6,
  },
+ {
+ "carbs": 49,
+ "fat": 16,
+ "name": "Gingerbread",
+ "prot": 0,
+ },
  {
  "carbs": 37,
  "fat": 9,

vite.config.ts

@@ -15,7 +15,7 @@ export default defineConfig({
  entry: resolve(__dirname, './src/index.ts'),
  formats: [ 'cjs', 'es' ],
  name: 'interlinqed',
- fileName: (format) => `index.${format}.js`
+ fileName: (format) => `index.${format}.js`,
  },
  },
 });