Added js-check.

Author: uhop

.github/workflows/tests.yml

@@ -35,3 +35,4 @@ jobs:
           npm run build --if-present
           npm test
           npm run ts-check --if-present
+          npm run js-check --if-present

package.json

@@ -20,6 +20,7 @@
     "test:seq:bun": "bun run `tape6-seq --self` --flags FO",
     "test:seq:deno": "deno run -A `tape6-seq --self` --flags FO",
     "ts-check": "tsc --noEmit",
+    "js-check": "tsc --project tsconfig.check.json",
     "ts-test": "tape6 --flags FO 'tests/test-*.*ts'",
     "ts-test:bun": "tape6-bun --flags FO 'tests/test-*.*ts'",
     "ts-test:deno": "tape6-deno --flags FO 'tests/test-*.*ts'",

src/index.js

@@ -101,8 +101,8 @@ const groupFunctions = (output, fn, index, fns) => {
 const produceStreams = item => {
   if (Array.isArray(item)) {
     if (!item.length) return null;
-    if (item.length == 1) return item[0] && chain.asStream(item[0]);
-    return chain.asStream(chain.gen(...item));
+    if (item.length == 1) return item[0] && /** @type {any} */ (chain).asStream(item[0]);
+    return /** @type {any} */ (chain).asStream(/** @type {any} */ (chain).gen(...item));
   }
   return item;
 };
@@ -124,7 +124,7 @@ const wrapFunctions = (fn, index, fns) => {
   if (index === fns.length - 1 && isWritableWebStream(fn)) {
     return Writable.fromWeb(fn, {objectMode: true});
   }
-  if (typeof fn == 'function') return chain.asStream(fn); // a function
+  if (typeof fn == 'function') return /** @type {any} */ (chain).asStream(fn); // a function
   throw TypeError('Item #' + index + ' is not a proper stream, nor a function.');
 };
 
@@ -193,16 +193,18 @@ const chain = (fns, options) => {
     output.on('finish', () => stream.push(null));
   }
 
-  stream = new Duplex({
-    writableObjectMode: true,
-    readableObjectMode: true,
-    ...options,
-    readable: isReadableNodeStream(output),
-    writable: isWritableNodeStream(input),
-    write: writeMethod,
-    final: finalMethod,
-    read: readMethod
-  });
+  stream = /** @type {Duplex & {streams: any[], input: any, output: any}} */ (
+    new Duplex({
+      writableObjectMode: true,
+      readableObjectMode: true,
+      ...options,
+      readable: isReadableNodeStream(output),
+      writable: isWritableNodeStream(input),
+      write: writeMethod,
+      final: finalMethod,
+      read: readMethod
+    })
+  );
   stream.streams = streams;
   stream.input = input;
   stream.output = output;

src/utils/reduceStream.js

@@ -5,7 +5,7 @@
 const {Writable} = require('node:stream');
 
 const defaultInitial = 0;
-const defaultReducer = (acc, value) => value;
+const defaultReducer = (_acc, value) => value;
 
 const reduceStream = (options, initial) => {
   if (!options || !options.reducer) {
@@ -18,25 +18,28 @@ const reduceStream = (options, initial) => {
     'reducer' in options && (reducer = options.reducer);
   }
 
-  const stream = new Writable({
-    objectMode: true,
-    ...options,
-    write(chunk, _, callback) {
-      const result = reducer.call(this, this.accumulator, chunk);
-      if (result && typeof result.then == 'function') {
-        result.then(
-          value => {
-            this.accumulator = value;
-            callback(null);
-          },
-          error => callback(error)
-        );
-      } else {
-        this.accumulator = result;
-        callback(null);
+  const stream = /** @type {import('node:stream').Writable & {accumulator: any}} */ (
+    new Writable({
+      objectMode: true,
+      ...options,
+      /** @this {import('node:stream').Writable & {accumulator: any}} */
+      write(chunk, _, callback) {
+        const result = reducer.call(this, this.accumulator, chunk);
+        if (result && typeof result.then == 'function') {
+          result.then(
+            value => {
+              this.accumulator = value;
+              callback(null);
+            },
+            error => callback(error)
+          );
+        } else {
+          this.accumulator = result;
+          callback(null);
+        }
       }
-    }
-  });
+    })
+  );
   stream.accumulator = accumulator;
 
   return stream;

tsconfig.check.json

@@ -0,0 +1,16 @@
+{
+  "include": ["src/**/*.js"],
+  "compilerOptions": {
+    "target": "ES2022",
+    "module": "Node16",
+    "moduleResolution": "Node16",
+    "noEmit": true,
+    "allowJs": true,
+    "checkJs": true,
+    "noUnusedLocals": true,
+    "noUnusedParameters": true,
+    "strict": false,
+    "skipLibCheck": true,
+    "types": ["node"]
+  }
+}