Ensure concurrency is an integer

Fixes #26
sindresorhus · Mar 5, 2020 · b342717 · b342717
1 parent bf03769
commit b342717
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Showing 4 changed files with 6 additions and 3 deletions.
diff --git a/index.d.ts b/index.d.ts
@@ -3,6 +3,8 @@ declare namespace pMap {
 		/**
 		Number of concurrently pending promises returned by `mapper`.
 
+		Must be an integer from 1 and up or `Infinity`.
+
 		@default Infinity
 		*/
 		readonly concurrency?: number;

diff --git a/index.js b/index.js
@@ -14,8 +14,8 @@ module.exports = async (
 			throw new TypeError('Mapper function is required');
 		}
 
-		if (!(typeof concurrency === 'number' && concurrency >= 1)) {
-			throw new TypeError(`Expected \`concurrency\` to be a number from 1 and up, got \`${concurrency}\` (${typeof concurrency})`);
+		if (!((Number.isSafeInteger(concurrency) || concurrency === Infinity) && concurrency >= 1)) {
+			throw new TypeError(`Expected \`concurrency\` to be an integer from 1 and up or \`Infinity\`, got \`${concurrency}\` (${typeof concurrency})`);
 		}
 
 		const result = [];

diff --git a/readme.md b/readme.md
@@ -59,7 +59,7 @@ Type: `object`
 
 ##### concurrency
 
-Type: `number`\
+Type: `number` (Integer)\
 Default: `Infinity`\
 Minimum: `1`
 

diff --git a/test.js b/test.js
@@ -91,6 +91,7 @@ test('async with concurrency: 2 (out of order time sequence)', async t => {
 
 test('enforce number in options.concurrency', async t => {
 	await t.throwsAsync(pMap([], () => {}, {concurrency: 0}), TypeError);
+	await t.throwsAsync(pMap([], () => {}, {concurrency: 1.5}), TypeError);
 	await t.notThrowsAsync(pMap([], () => {}, {concurrency: 1}));
 	await t.notThrowsAsync(pMap([], () => {}, {concurrency: 10}));
 	await t.notThrowsAsync(pMap([], () => {}, {concurrency: Infinity}));