Add tests

Author: ahejlsberg

tests/cases/compiler/genericFunctionInference1.ts

@@ -0,0 +1,82 @@
+// @strict: true
+// @target: es2015
+
+declare function pipe<A extends any[], B>(ab: (...args: A) => B): (...args: A) => B;
+declare function pipe<A extends any[], B, C>(ab: (...args: A) => B, bc: (b: B) => C): (...args: A) => C;
+declare function pipe<A extends any[], B, C, D>(ab: (...args: A) => B, bc: (b: B) => C, cd: (c: C) => D): (...args: A) => D;
+
+declare function list<T>(a: T): T[];
+declare function box<V>(x: V): { value: V };
+
+const f00 = pipe(list);
+const f01 = pipe(list, box);
+const f02 = pipe(x => list(x), box);
+const f03 = pipe(list, x => box(x));
+const f04 = pipe(x => list(x), x => box(x))
+const f05 = pipe(list, pipe(box));
+const f06 = pipe(x => list(x), pipe(box));
+const f07 = pipe(x => list(x), pipe(x => box(x)));
+
+const f10: <T>(x: T) => T[] = pipe(list);
+const f11: <T>(x: T) => { value: T[] } = pipe(list, box);
+const f12: <T>(x: T) => { value: T[] } = pipe(x => list(x), box);
+const f13: <T>(x: T) => { value: T[] } = pipe(list, x => box(x));
+const f14: <T>(x: T) => { value: T[] } = pipe(x => list(x), x => box(x))
+const f15: <T>(x: T) => { value: T[] } = pipe(list, pipe(box));
+const f16: <T>(x: T) => { value: T[] } = pipe(x => list(x), pipe(box));
+const f17: <T>(x: T) => { value: T[] } = pipe(x => list(x), pipe(x => box(x)));
+
+// #29904.2
+
+const fn20 = pipe((_a?: {}) => 1);
+
+// #29904.3
+
+type Fn = (n: number) => number;
+const fn30: Fn = pipe(
+    x => x + 1,
+    x => x * 2,
+);
+
+const promise = Promise.resolve(1);
+promise.then(
+    pipe(
+        x => x + 1,
+        x => x * 2,
+    ),
+);
+
+// #29904.4
+
+declare const getString: () => string;
+declare const orUndefined: (name: string) => string | undefined;
+declare const identity: <T>(value: T) => T;
+
+const fn40 = pipe(
+    getString,
+    string => orUndefined(string),
+    identity,
+);
+
+// #29904.6
+
+declare const getArray: () => string[];
+declare const first: <T>(ts: T[]) => T;
+
+const fn60 = pipe(
+    getArray,
+    x => x,
+    first,
+);
+
+const fn61 = pipe(
+    getArray,
+    identity,
+    first,
+);
+
+const fn62 = pipe(
+    getArray,
+    x => x,
+    x => first(x),
+);