From b779e6268c87fbfc51081ba6d03964c9c8ec3880 Mon Sep 17 00:00:00 2001
From: Deddy Kosasih <dkosasih@gmail.com>
Date: Sat, 17 Nov 2018 22:56:47 +1100
Subject: [PATCH 1/2] test(dtslint): add dtslint test for scan operator (#4093)

---
 spec-dtslint/operators/scan-spec.ts | 23 +++++++++++++++++++++++
 1 file changed, 23 insertions(+)
 create mode 100644 spec-dtslint/operators/scan-spec.ts

diff --git a/spec-dtslint/operators/scan-spec.ts b/spec-dtslint/operators/scan-spec.ts
new file mode 100644
index 0000000000..b41d7ae039
--- /dev/null
+++ b/spec-dtslint/operators/scan-spec.ts
@@ -0,0 +1,23 @@
+import { of } from 'rxjs';
+import { scan } from 'rxjs/operators';
+
+it('should enforce accumulator function as parameter', () => {
+  const a = of(1, 2, 3).pipe(scan()); // $ExpectError
+});
+
+it('should infer correctly with single T value', () => {
+  const a = of(1, 2, 3).pipe(scan((acc, val, i) => acc + val)); // $ExpectType Observable<number>
+});
+
+it('should do a type check on seed parameter', () => {
+  const b = of(1, 2, 3).pipe(scan((acc, val, i) => acc + val, 0)); // $ExpectType Observable<number>
+  const a = of(1, 2, 3).pipe(scan((acc, val, i) => acc + val, 'y')); // $ExpectError
+});
+
+it('should infer correctly with Array of T value', () => {
+  const a = of(1, 2, 3).pipe(scan((acc: number[], val: number, i) => [...acc, val])); // $ExpectType Observable<number[]>
+});
+
+it('should infer correctly with type change accumulator', () => {
+  const a = of(1, 2, 3).pipe(scan((acc: string, val: number, i) => `${acc} ' ' ${val}`)); // $ $expectType Observable<string>
+});

From 8d5551a7e50806839546bd7a8b6117c3fb8b3077 Mon Sep 17 00:00:00 2001
From: Deddy Kosasih <dkosasih@gmail.com>
Date: Wed, 30 Jan 2019 23:19:04 +0700
Subject: [PATCH 2/2] test(dtslint): change scan operator dtslint test to
 reduce-like (#4093)

---
 spec-dtslint/operators/scan-spec.ts | 20 ++++++++------------
 1 file changed, 8 insertions(+), 12 deletions(-)

diff --git a/spec-dtslint/operators/scan-spec.ts b/spec-dtslint/operators/scan-spec.ts
index b41d7ae039..7f11324c9f 100644
--- a/spec-dtslint/operators/scan-spec.ts
+++ b/spec-dtslint/operators/scan-spec.ts
@@ -1,23 +1,19 @@
 import { of } from 'rxjs';
 import { scan } from 'rxjs/operators';
 
-it('should enforce accumulator function as parameter', () => {
+it('should enforce parameter', () => {
   const a = of(1, 2, 3).pipe(scan()); // $ExpectError
 });
 
-it('should infer correctly with single T value', () => {
-  const a = of(1, 2, 3).pipe(scan((acc, val, i) => acc + val)); // $ExpectType Observable<number>
+it('should infer correctly ', () => {
+  const a = of(1, 2, 3).pipe(scan((x, y, z) => x + 1)); // $ExpectType Observable<number>
 });
 
-it('should do a type check on seed parameter', () => {
-  const b = of(1, 2, 3).pipe(scan((acc, val, i) => acc + val, 0)); // $ExpectType Observable<number>
-  const a = of(1, 2, 3).pipe(scan((acc, val, i) => acc + val, 'y')); // $ExpectError
+it('should infer correctly for accumulator of type array', () => {
+  const a = of(1, 2, 3).pipe(scan((x: number[], y: number, i: number) => x, [])); // $ExpectType Observable<number[]>
 });
 
-it('should infer correctly with Array of T value', () => {
-  const a = of(1, 2, 3).pipe(scan((acc: number[], val: number, i) => [...acc, val])); // $ExpectType Observable<number[]>
-});
-
-it('should infer correctly with type change accumulator', () => {
-  const a = of(1, 2, 3).pipe(scan((acc: string, val: number, i) => `${acc} ' ' ${val}`)); // $ $expectType Observable<string>
+it('should accept seed parameter of the same type', () => {
+  const a = of(1, 2, 3).pipe(scan((x, y, z) => x + 1, 5)); // $ExpectType Observable<number>
+  const b = of(1, 2, 3).pipe(scan((x, y, z) => x + 1, '5')); // $ExpectError
 });