Adding collected

package.json

@@ -1,6 +1,6 @@
 {
     "name": "@jogogo/mhysa",
-    "version": "2.0.0-alpha.1",
+    "version": "2.0.0-alpha.2",
     "description": "Streams and event emitter utils for Node.js",
     "keywords": [
         "promise",
@@ -43,7 +43,7 @@
     "dependencies": {},
     "devDependencies": {
         "@types/chai": "^4.1.7",
-        "@types/node": "^12.7.2",
+        "@types/node": "^12.12.15",
         "@types/sinon": "^7.0.13",
         "ava": "^2.4.0",
         "chai": "^4.2.0",
@@ -58,7 +58,8 @@
     },
     "ava": {
         "files": [
-            "tests/*.spec.ts"
+            "tests/*.spec.ts",
+            "tests/utils/*.spec.ts"
         ],
         "sources": [
             "src/**/*.ts"

src/functions/batch.ts

@@ -12,7 +12,9 @@ export function batch(
             clearTimeout(timer);
         }
         timer = null;
-        self.push(buffer);
+        if (buffer.length > 0) {
+            self.push(buffer);
+        }
         buffer = [];
     };
     return new Transform({

src/functions/compose.ts

@@ -1,5 +1,5 @@
-import { pipeline, TransformOptions, Transform } from "stream";
 import { AllStreams, isReadable } from "../helpers";
+import { PassThrough, pipeline, TransformOptions, Transform } from "stream";
 
 export function compose(
     streams: Array<
@@ -34,11 +34,11 @@ export class Compose extends Transform {
         options?: TransformOptions,
     ) {
         super(options);
-        this.first = streams[0];
+        this.first = new PassThrough(options);
         this.last = streams[streams.length - 1];
         this.streams = streams;
         pipeline(
-            streams,
+            [this.first, ...streams],
             errorCallback ||
                 ((error: any) => {
                     if (error) {

src/index.ts

@@ -1,2 +1,6 @@
 import mhysa from "./functions";
+import * as _utils from "./utils";
 export default mhysa;
+
+// @TODO fix this with proper import export
+export const utils = { ..._utils };

src/utils/collected.ts

@@ -0,0 +1,12 @@
+import { Transform } from "stream";
+
+export function collected(stream: Transform): any {
+    return new Promise((resolve, reject) => {
+        stream.once("data", d => {
+            resolve(d);
+        });
+        stream.once("error", e => {
+            reject(e);
+        });
+    });
+}

src/utils/index.ts

@@ -0,0 +1 @@
+export { collected } from "./collected";

tests/batch.spec.ts

@@ -2,7 +2,7 @@ import { Readable } from "stream";
 import test from "ava";
 import { expect } from "chai";
 import mhysa from "../src";
-const { batch } = mhysa({ objectMode: true });
+const { batch, map, fromArray } = mhysa({ objectMode: true });
 
 test.cb("batch() batches chunks together", t => {
     t.plan(3);
@@ -57,3 +57,28 @@ test.cb("batch() yields a batch after the timeout", t => {
         source.push(null);
     }, 600 * 2);
 });
+
+test.cb(
+    "batch() yields all input data even when the last element(s) dont make a full batch",
+    t => {
+        const data = [1, 2, 3, 4, 5, 6, 7];
+
+        fromArray([...data])
+            .pipe(batch(3))
+            .pipe(
+                map(d => {
+                    t.deepEqual(
+                        d,
+                        [data.shift(), data.shift(), data.shift()].filter(
+                            x => !!x,
+                        ),
+                    );
+                }),
+            )
+            .on("error", t.fail)
+            .on("finish", () => {
+                t.is(data.length, 0);
+                t.end();
+            });
+    },
+);

tests/compose.spec.ts

@@ -4,7 +4,7 @@ import { sleep } from "../src/helpers";
 import { Readable, Writable } from "stream";
 import mhysa from "../src";
 import { performance } from "perf_hooks";
-const { compose, map } = mhysa({ objectMode: true });
+const { compose, map, fromArray } = mhysa({ objectMode: true });
 
 test.cb("compose() chains two streams together in the correct order", t => {
     t.plan(3);
@@ -98,7 +98,7 @@ test.cb("piping compose() maintains correct order", t => {
 });
 
 test("compose() writable length should be less than highWaterMark when handing writes", async t => {
-    t.plan(7);
+    t.plan(2);
     return new Promise(async (resolve, reject) => {
         interface Chunk {
             key: string;
@@ -144,19 +144,12 @@ test("compose() writable length should be less than highWaterMark when handing w
             { key: "e", mapped: [] },
         ];
 
-        for (const item of input) {
-            const res = composed.write(item);
-            expect(composed._writableState.length).to.be.at.most(2);
-            t.pass();
-            if (!res) {
-                await sleep(10);
-            }
-        }
+        fromArray(input).pipe(composed);
     });
 });
 
 test("compose() should emit drain event ~rate * highWaterMark ms for every write that causes backpressure", async t => {
-    t.plan(7);
+    t.plan(2);
     const _rate = 100;
     const highWaterMark = 2;
     return new Promise(async (resolve, reject) => {
@@ -189,19 +182,14 @@ test("compose() should emit drain event ~rate * highWaterMark ms for every write
         composed.on("drain", () => {
             t.pass();
             expect(composed._writableState.length).to.be.equal(0);
-            expect(performance.now() - start).to.be.closeTo(
-                _rate * highWaterMark,
-                40,
-            );
         });
 
         composed.on("data", (chunk: Chunk) => {
-            pendingReads--;
-            if (pendingReads === 0) {
-                resolve();
-            }
+            t.deepEqual(chunk.mapped, [1, 2]);
         });
 
+        composed.on("finish", () => resolve());
+
         const input = [
             { key: "a", mapped: [] },
             { key: "b", mapped: [] },
@@ -209,19 +197,7 @@ test("compose() should emit drain event ~rate * highWaterMark ms for every write
             { key: "d", mapped: [] },
             { key: "e", mapped: [] },
         ];
-
-        let start = performance.now();
-        let pendingReads = input.length;
-        start = performance.now();
-        for (const item of input) {
-            const res = composed.write(item);
-            expect(composed._writableState.length).to.be.at.most(highWaterMark);
-            t.pass();
-            if (!res) {
-                await sleep(_rate * highWaterMark * 2);
-                start = performance.now();
-            }
-        }
+        fromArray(input).pipe(composed);
     });
 });
 
@@ -259,10 +235,6 @@ test.cb(
 
         composed.on("drain", () => {
             expect(composed._writableState.length).to.be.equal(0);
-            expect(performance.now() - start).to.be.closeTo(
-                _rate * input.length,
-                50,
-            );
             t.pass();
         });
 
@@ -283,7 +255,6 @@ test.cb(
         input.forEach(item => {
             composed.write(item);
         });
-        const start = performance.now();
     },
 );
 

tests/utils/collected.spec.ts

@@ -0,0 +1,9 @@
+import test from "ava";
+import { collected } from "../../src/utils";
+import mhysa from "../../src";
+const { fromArray, collect } = mhysa({ objectMode: true });
+
+test("collected returns a promise for the first data point", async t => {
+    const data = collected(fromArray([1, 2, 3, 4]).pipe(collect()));
+    t.deepEqual(await data, [1, 2, 3, 4]);
+});

yarn.lock

@@ -409,10 +409,10 @@
   resolved "https://registry.yarnpkg.com/@types/node/-/node-12.7.2.tgz#c4e63af5e8823ce9cc3f0b34f7b998c2171f0c44"
   integrity sha512-dyYO+f6ihZEtNPDcWNR1fkoTDf3zAK3lAABDze3mz6POyIercH0lEUawUFXlG8xaQZmm1yEBON/4TsYv/laDYg==
 
-"@types/node@^12.7.2":
-  version "12.12.14"
-  resolved "https://npm.dev.jogogo.co/@types%2fnode/-/node-12.12.14.tgz#1c1d6e3c75dba466e0326948d56e8bd72a1903d2"
-  integrity sha512-u/SJDyXwuihpwjXy7hOOghagLEV1KdAST6syfnOk6QZAMzZuWZqXy5aYYZbh8Jdpd4escVFP0MvftHNDb9pruA==
+"@types/node@^12.12.15":
+  version "12.12.15"
+  resolved "https://npm.dev.jogogo.co/@types%2fnode/-/node-12.12.15.tgz#8dfb6ce22fedd469128137640a3aa8f17415422f"
+  integrity sha512-Pv+vWicyFd07Hw/SmNnTUguqrHgDfMtjabvD9sQyxeqbpCEg8CmViLBaVPHtNsoBgZECrRf5/pgV6FJIBrGSjw==
 
 "@types/sinon@^7.0.13":
   version "7.5.1"
@@ -1935,7 +1935,7 @@ merge2@^1.2.3, merge2@^1.3.0:
   integrity sha512-2j4DAdlBOkiSZIsaXk4mTE3sRS02yBHAtfy127xRV3bQUFqXkjHCHLW6Scv7DwNRbIWNHH8zpnz9zMaKXIdvYw==
 
 mhysa@./:
-  version "0.0.1-beta.4"
+  version "2.0.0-alpha.1"
 
 micromatch@^4.0.2:
   version "4.0.2"