Fix check for invalid concurrency argument

Fixes #15
sindresorhus · Aug 18, 2019 · 7c119d3 · 7c119d3
1 parent 86be63a
commit 7c119d3
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Showing 3 changed files with 12 additions and 3 deletions.
diff --git a/index.js b/index.js
@@ -2,8 +2,8 @@
 const pTry = require('p-try');
 
 const pLimit = concurrency => {
-	if (concurrency < 1) {
-		throw new TypeError('Expected `concurrency` to be a number from 1 and up');
+	if (!((Number.isInteger(concurrency) || concurrency === Infinity) && concurrency > 0)) {
+		return Promise.reject(new TypeError('Expected `concurrency` to be a number from 1 and up'));
 	}
 
 	const queue = [];

diff --git a/readme.md b/readme.md
@@ -40,7 +40,8 @@ Returns a `limit` function.
 #### concurrency
 
 Type: `number`<br>
-Minimum: `1`
+Minimum: `1`<br>
+Default: `Infinity`
 
 Concurrency limit.
 

diff --git a/test.js b/test.js
@@ -120,3 +120,11 @@ test('activeCount and pendingCount properties', async t => {
 	t.is(limit.activeCount, 0);
 	t.is(limit.pendingCount, 0);
 });
+
+test('throws on invalid concurrency argument', async t => {
+	await t.throwsAsync(pLimit(0));
+	await t.throwsAsync(pLimit(-1));
+	await t.throwsAsync(pLimit(1.2));
+	await t.throwsAsync(pLimit(undefined));
+	await t.throwsAsync(pLimit(true));
+});