is-map

npmv2.0.3TypeScript

Is this value a JS Map? This module works cross-realm/iframe, and despite ES6 @@toStringTag.

Adopt with care

is-map is usable, with caveats. Last published 915 days ago.

?Adoption: grade ?, Not reported by this registry.
No download data reported for this package yet.
DMaintenance: grade D, Poor — a real concern.
Last published 915 days ago.
AWeight: grade A, Excellent.
Zero runtime dependencies, about 20 KB installed.
BSupply chain: grade B, Good.
This package has a single maintainer (bus factor of 1).
ALicense: grade A, Excellent.
MIT — permissive, with no copyleft found in the dependency tree.

Grades are computed deterministically from registry metadata collected by PackageGraph — downloads, dependents, publish dates, the resolved dependency tree, maintainer count, and declared licenses. No third-party scores are used.

Install cost

What you actually take on by adding is-map to a project.

Direct dependencies

Runtime packages this one declares itself.

Total installed

Distinct packages in the full runtime tree, deduplicated the way a package manager would.

20 KB

Install size

Unpacked size of this package plus its entire runtime tree.

—

Tree depth

Longest resolved dependency chain below this package.

Compatibility

Node.js: node >= 0.4
Module format: CommonJS only
TypeScript: Types included
Install scripts: None

Quick start

A usage example from the is-map README.

jsFull README ↗

var isMap = require('is-map');
assert(!isMap(function () {}));
assert(!isMap(null));
assert(!isMap(function* () { yield 42; return Infinity; });
assert(!isMap(Symbol('foo')));
assert(!isMap(1n));
assert(!isMap(Object(1n)));

assert(!isMap(new Set()));
assert(!isMap(new WeakSet()));
assert(!isMap(new WeakMap()));

assert(isMap(new Map()));

Example truncated — see the full README.

is-map vs the alternatives

Packages solving a similar problem in the npm ecosystem, compared on the signals that drive an adoption decision.

Package	Weekly downloads	Dependents	License	Last release
is-mapthis page	0	1	MIT	2 years ago
is-set	0	1	MIT	1 day ago
jsesc	0	1	MIT	1 day ago
p-map	0	1	MIT	1 day ago
p-locate	216.9M	1	MIT	1 day ago
@jridgewell/gen-mapping	163.4M	4	MIT	1 day ago

Dependencies

Declared by is-map v2.0.3. Runtime dependencies are installed with the package; dev dependencies are not.

Dev (19)

@arethetypeswrong/cli ^0.15.0@ljharb/eslint-config ^21.1.0@types/for-each ^0.3.3@types/object-inspect ^1.8.4@types/tape ^5.6.4aud ^2.0.4auto-changelog ^2.4.0core-js ^2.6.12es5-shim ^4.6.7es6-shim ^0.35.8eslint =8.8.0for-each ^0.3.3in-publish ^2.0.1npmignore ^0.3.1nyc ^10.3.2object-inspect ^1.13.1safe-publish-latest ^2.0.0tape ^5.7.5typescript ^5.5.0-dev.20240308

Used by

Popular packages that depend on is-map.

es-get-iteratornpm

Get an iterator for any JS language value. Works robustly across all environments, all versions.

↓ 0/wk◈ 1 dependents⚖ MIT

Relationship graph

Dependencies (left) and dependents (right) of is-map.

is-map dependencies dependents

Frequently installed together

isarraynpm

Array#isArray for older browsers

↓ 174.9M/wk◈ 3 dependents⚖ MIT

eslintnpm

An AST-based pattern checker for JavaScript.

↓ 138.4M/wk◈ 279 dependents⚖ MITTS

call-bindnpm

Robustly `.call.bind()` a function

↓ 80.7M/wk◈ 5 dependents⚖ MIT

stop-iteration-iteratornpm

Firefox 17-26 iterators throw a StopIteration object to indicate "done". This normalizes it.

↓ 69.2M/wk◈ 1 dependents⚖ MITTS

is-argumentsnpm

Is this an arguments object? It's a harder question than you think.

↓ 38.9M/wk◈ 2 dependents⚖ MITTS

get-intrinsicnpm

Get and robustly cache all JS language-level intrinsics at first require time

↓ 0/wk◈ 8 dependents⚖ MIT

object-inspectnpm

string representations of objects in node and the browser

↓ 0/wk◈ 24 dependents⚖ MIT

is-setnpm

Is this value a JS Set? This module works cross-realm/iframe, and despite ES6 @@toStringTag.

↓ 0/wk◈ 1 dependents⚖ MITTS

Release history

No releases in the last two years, typically about 362 days apart.

Recent versions of is-map
Version	Published	Size	License
2.0.3latest	2 years ago	20 KB	MIT
2.0.2	5 years ago	12 KB	MIT
2.0.1	6 years ago	9.6 KB	MIT
2.0.0	6 years ago	8.6 KB	MIT
1.0.1	11 years ago	—	MIT
1.0.0	11 years ago	—	MIT

Overview

is-map is an npm package that is this value a JS Map? This module works cross-realm/iframe, and despite ES6 @@toStringTag. It has 1 known dependents in the graph. The latest version is 2.0.3, released under the MIT license.

Who should use it

Teams working in the npm ecosystem who need is this value a JS Map? This module works cross-realm/iframe, and despite ES6 @@toStringTag and value a focused solution.

When not to use it

Consider an alternative if you need to minimize your dependency tree, or if a more actively-maintained option better fits your npm stack.

Pros

Ships TypeScript type definitions.
Clear open-source license (MIT).

Cons

Large dependency tree (19 direct dependencies) increases install size and audit surface.

Auto-generated from collected registry metadata. No external claims are inferred.

Maintainers

ljharb

Keywords

collection is map robust set

Funding

https://github.com/sponsors/ljharb

Frequently asked questions

Should I use is-map?

is-map is usable, with caveats. Last published 915 days ago.

How do I install is-map?

Run `npm install is-map` to add is-map to your npm project.

What license is is-map released under?

is-map is distributed under the MIT license.

How popular is is-map?

npm does not publish download counts. Within PackageGraph's crawl, 1 known packages depend on is-map.

Is is-map still maintained?

The most recent release of is-map (v2.0.3) was published 2 years ago.

Does is-map run install scripts?

No. is-map does not define preinstall, install, or postinstall scripts, so installing it does not execute publisher-supplied code.