document concurrent

Author: nicojs

.prettierignore

@@ -1 +1,2 @@
-.mocharc.jsonc
+.mocharc.jsonc
+CHANGELOG.md

README.md

@@ -168,3 +168,19 @@ const localInstaller = new LocalInstaller(
   { npmEnv: Object.assign({}, process.env, { envVar: 'envValue' }) },
 );
 ```
+
+##### Max concurrent installs
+
+In some cases it might be useful to control the max concurrent installs. You can do it by passing `options` to `LocalInstaller`'s constructor.
+
+```javascript
+const localInstaller = new LocalInstaller(
+  {
+    /*1*/ '.': ['../sibling1', '../sibling2'],
+    /*2*/ '../dependant': ['.'],
+  },
+  { concurrent: 1 },
+);
+```
+
+The default concurrency is `os.cpus().length`.

test/unit/LocalInstaller.spec.ts

@@ -284,10 +284,10 @@ describe('LocalInstaller install', () => {
     it('should install with the specified concurrency', async () => {
       const calls: ((res: Result<Options>) => void)[] = [];
       helper.execStub.callsFake((file, args) => {
-        if(file === 'npm' && args?.includes('pack')) {
+        if (file === 'npm' && args?.includes('pack')) {
           return Promise.resolve(createExecaResult()) as ResultPromise;
         }
-        return new Promise(res => {
+        return new Promise((res) => {
           calls.push(res);
         }) as ResultPromise;
       });
@@ -301,7 +301,7 @@ describe('LocalInstaller install', () => {
       await tick();
       expect(calls).to.have.lengthOf(2);
       calls[1](createExecaResult());
-      await onGoingInstall
+      await onGoingInstall;
     });
   });