is-stream is a Node.js utility that checks whether a value is a Node.js stream. It exports functions like isStream, isWritableStream, and isReadableStream to help you verify stream types before using them, with an option (checkOpen) to return false for already closed streams.
Project status
- The repository appears to be in maintenance mode or dormant, with the last upstream push on 2024-10-28 and the most recent published update noted in 2024-02, with no evidence of continued updates closer to today (2026-09-10).
- Update cadence looks low and irregular, with a relatively active period in 2021 to 2024, then a long quiet gap after 2024 (no recent updates shown in the provided history).
AI summary generated
Recent updates
v4.0.1
v4.0.1 is described in the release notes only as a documentation fix. The actual diff shows no runtime implementation changes, only updates to the type declaration comments and README around the Options.checkOpen default.
v4.0.0
v4.0.0 requires Node.js 18 and adds a new option to influence whether the utility checks that the provided stream is still open. It also broadens detection to support HTTP message/response stream instances.
BreakingFeaturesv3.0.0
v3.0.0 converts the package to pure ESM and replaces the previous default export pattern. The implementation was refactored from a single callable function with attached properties into separately exported named functions for checking writable, readable, duplex, and transform streams.
Breakingv2.0.1
v2.0.1 makes a targeted change to `isStream.transform` detection. Release notes mention only this fix, but the diff also includes type-definition and test-related updates that could affect downstream TypeScript and stream classification expectations.
v2.0.0
v2.0.0 introduces new TypeScript definitions for the package and raises the minimum supported Node.js version. The release includes a breaking change requiring Node.js 8, which may affect users on older runtimes.
BreakingFeatures