add some type testing

repeaterjs · Sep 2, 2020 · a5c6628 · a5c6628
1 parent 787932a
commit a5c6628
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Showing 3 changed files with 108 additions and 7 deletions.
diff --git a/packages/pubsub/src/__tests__/pubsub.ts b/packages/pubsub/src/__tests__/pubsub.ts
@@ -44,5 +44,6 @@ describe("InMemoryPubSub", () => {
   test("close", () => {
     const pubsub = new InMemoryPubSub();
     pubsub.close();
+    expect(1).toEqual(1);
   });
 });
diff --git a/packages/repeater/src/__tests__/combinators.ts b/packages/repeater/src/__tests__/combinators.ts
@@ -1048,3 +1048,101 @@ describe("combinators", () => {
     });
   });
 });
+
+// Testing type inference.
+function _types() {
+  /* eslint-disable */
+  let iteration1: Promise<IteratorResult<number>>;
+  let iteration2: Promise<IteratorResult<string>>;
+  let iteration3: Promise<IteratorResult<number | string>>;
+  let iteration4: Promise<IteratorResult<number | string | null>>;
+
+  const repeater1 = new Repeater<number, number>((push, stop) => {
+    push(1);
+    return -1;
+  });
+  const repeater2 = new Repeater<string, string>((push, stop) => {
+    push("hello");
+    return "goodbye";
+  });
+
+  const race1 = Repeater.race([Promise.resolve(null), repeater1]);
+  iteration1 = race1.next();
+  // @ts-expect-error
+  iteration2 = race1.next();
+  iteration3 = race1.next();
+  iteration4 = race1.next();
+
+  const race2 = Repeater.race([Promise.resolve(null), repeater1, repeater2]);
+
+  // @ts-expect-error
+  iteration1 = race2.next();
+  // @ts-expect-error
+  iteration2 = race2.next();
+  iteration3 = race2.next();
+  iteration4 = race1.next();
+
+  const merge1 = Repeater.merge([Promise.resolve("hello"), Promise.resolve(1)]);
+  // @ts-expect-error
+  iteration1 = merge1.next();
+  // @ts-expect-error
+  iteration2 = merge1.next();
+  iteration3 = merge1.next();
+  iteration4 = merge1.next();
+
+  const merge2 = Repeater.merge([Promise.resolve(null), repeater1, repeater2]);
+
+  // @ts-expect-error
+  iteration1 = merge2.next();
+  // @ts-expect-error
+  iteration2 = merge2.next();
+  // @ts-expect-error
+  iteration3 = merge2.next();
+  iteration4 = merge2.next();
+
+  let iteration5: Promise<IteratorResult<[number]>>;
+  let iteration6: Promise<IteratorResult<[string]>>;
+  let iteration7: Promise<IteratorResult<[number, string]>>;
+  let iteration8: Promise<IteratorResult<[null, number, string]>>;
+
+  const zip1 = Repeater.zip([repeater1, repeater2]);
+  // @ts-expect-error
+  iteration5 = zip1.next();
+  // @ts-expect-error
+  iteration6 = zip1.next();
+  iteration7 = zip1.next();
+  // @ts-expect-error
+  iteration8 = zip1.next();
+
+  const zip2 = Repeater.zip([Promise.resolve(null), repeater1, repeater2]);
+  // @ts-expect-error
+  iteration5 = zip2.next();
+  // @ts-expect-error
+  iteration6 = zip2.next();
+  // @ts-expect-error
+  iteration7 = zip2.next();
+  iteration8 = zip2.next();
+
+  const latest1 = Repeater.latest([repeater1, repeater2]);
+  // @ts-expect-error
+  iteration5 = latest1.next();
+  // @ts-expect-error
+  iteration6 = latest1.next();
+  iteration7 = latest1.next();
+  // @ts-expect-error
+  iteration8 = latest1.next();
+
+  const latest2 = Repeater.latest([
+    Promise.resolve(null),
+    repeater1,
+    repeater2,
+  ]);
+  // @ts-expect-error
+  iteration5 = latest2.next();
+  // @ts-expect-error
+  iteration6 = latest2.next();
+  // @ts-expect-error
+  iteration7 = latest2.next();
+  iteration8 = latest2.next();
+  /* eslint-enable */
+}
diff --git a/packages/repeater/src/repeater.ts b/packages/repeater/src/repeater.ts
@@ -184,7 +184,7 @@ interface NextOperation<T, TReturn, TNext> {
   // The value passed to the next method.
   value: PromiseLike<TNext> | TNext | undefined;
   // The resolve function of the promise returned from next.
-  resolve(result: Promise<IteratorResult<T, TReturn>>): unknown;
+  resolve(iteration: Promise<IteratorResult<T, TReturn>>): unknown;
 }
 
 /*** REPEATER STATES ***/
@@ -755,7 +755,7 @@ type Contender<T> =
   | T;
 
 function zip(contenders: []): Repeater<never>;
-function zip<T>(contenders: Iterable<Contender<T>>): Repeater<T[]>;
+function zip<T>(contenders: Iterable<Contender<T>>): Repeater<[T]>;
 // prettier-ignore
 function zip<T1, T2>(contenders: [Contender<T1>, Contender<T2>]): Repeater<[T1, T2]>;
 // prettier-ignore
@@ -796,9 +796,9 @@ function zip(contenders: Iterable<any>) {
           (err) => stop(err),
         );
 
-        const iterations: Array<IteratorResult<unknown>> | undefined = await new Promise(
-          (resolve) => (advance = resolve),
-        );
+        const iterations:
+          | Array<IteratorResult<unknown>>
+          | undefined = await new Promise((resolve) => (advance = resolve));
         if (iterations === undefined) {
           return;
         }
@@ -818,7 +818,7 @@ function zip(contenders: Iterable<any>) {
 }
 
 function latest(contenders: []): Repeater<never>;
-function latest<T>(contenders: Iterable<Contender<T>>): Repeater<T[]>;
+function latest<T>(contenders: Iterable<Contender<T>>): Repeater<[T]>;
 // prettier-ignore
 function latest<T1, T2>(contenders: [Contender<T1>, Contender<T2>]): Repeater<[T1, T2]>;
 // prettier-ignore
@@ -850,7 +850,9 @@ function latest(contenders: Iterable<any>) {
     }
 
     let advance!: (iterations?: Array<IteratorResult<unknown>>) => unknown;
-    const advances: Array<(iteration?: IteratorResult<unknown>) => unknown> = [];
+    const advances: Array<(
+      iteration?: IteratorResult<unknown>,
+    ) => unknown> = [];
     let stopped = false;
     stop.then(() => {
       advance();