fix(stream-parser): respect backpressure when importing readable streams

[jeswr]

Use stream.pipe(this) when importing a readable stream so its producer pauses when the parser's buffers fill and resumes as quads are consumed. Previously import() attached a data listener and ignored write() returning false, allowing an unread parser to consume and retain the entire source.

Keep explicit source-error forwarding and the existing data/end listener fallback for RDF/JS event sources that do not provide pipe(). The return value remains the parser.

The regression test imports 30,000 one-triple chunks, checks that production pauses before exhausting the input, then consumes and verifies all 30,000 quads. It fails on the original implementation and passes with this patch. A second test covers an EventEmitter-only source.

Validation: all 6,891 tests pass with 100% coverage; ESLint, Node/browser builds, and git diff --check pass.

This fixes pre-existing behavior on main and is independent of #721 and the separate readable-buffer initialization change.

[Copilot]

🟢 Approval recommended

The change is small, aligns with Node stream backpressure semantics, preserves the documented fallback behavior, and is covered by targeted regression tests.

Pull request overview

This PR updates StreamParser#import() to respect Node stream backpressure when the imported source is a proper readable stream, preventing the parser from buffering the entire input when its output is not being consumed.

Changes:

• Switch StreamParser#import() to use stream.pipe(this) when available, preserving backpressure behavior.
• Keep explicit source error forwarding and retain the existing data/end listener fallback for non-stream event sources.
• Add regression tests covering (1) backpressure pausing/resuming and (2) the non-pipe() EventEmitter fallback behavior.

File summaries

File	Description
test/N3StreamParser-test.js	Adds regression tests for backpressure behavior and for importing an EventEmitter-only source.
src/N3StreamParser.js	Uses pipe() for readable streams to respect backpressure; preserves error forwarding and fallback event-based import.

Review details

• Files reviewed: 2/2 changed files
• Comments generated: 0
• Review effort level: Lite

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[github-actions]

🎉 This PR is included in version 2.7.6 🎉

The release is available on:

• npm package (@latest dist-tag)
• GitHub release

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