df_safer_dart 0.21.0

A package inspired by functional programming, designed to enhance the structure, safety, and debuggability of mission-critical code.

Changelog

0.21.0

• feat: df_safer_dart now re-exports df_safer_dart_annotations. Consumers can use @sendable, @noFutures, @mustBeAnonymous, etc. without adding a separate dependency.
• feat: new Resolvable.flatMap(...) — monadic bind that absorbs throws and short-circuits on Err.
• feat: new Option.mapNone, Resolvable.mapSync, Resolvable.mapAsync (all @visibleForTesting) for pair-axis symmetry with mapSome / mapOk / mapErr.
• fix: user-thrown Err is now preserved verbatim (statusCode and breadcrumbs intact) across every transform method — mapOk, mapErr, mapSome, transf, flatMap, ifOk/ifErr, ifSync/ifAsync, whenComplete, resultMap, Outcome.reduce, SafeCompleter.transf, ConcurrentTaskBatch.onError, TaskSequencer. Previously these would re-wrap the Err and drop its metadata.
• fix: onFinalize throws in Sync(...), Async(...), and Resolvable(...) are now absorbed into the result instead of escaping the factory or rejecting Async.value with an uncaught error.
• fix: letIntOrNone(...) now correctly rejects double.infinity and out-of-range doubles on dart2js (where is int accepts integer-valued doubles).
• fix: combineSync(...) and combineAsync(...) now consume their iterable input exactly once — single-pass generators no longer silently lose all elements.
• fix: Lazy.singleton and Lazy.factory now absorb constructor throws into Sync.err(...) and detect re-entrant access, returning a structured Err instead of a stack overflow.
• fix: SafeCompleter.transf(...) now forwards errors from the source completer — an Err source no longer leaves the derived completer dangling forever.
• fix: Stream.toSafe() now preserves the upstream stackTrace on Err instead of capturing a new one at the wrapper call site.
• fix: Err(...), Err.toString(), and Here.call() / basepath / location no longer crash on dart2wasm — the WASM-host trap in path.Style.platform is caught and falls back to an empty trace / None.
• fix: Async.end() is now guaranteed not to throw, even on hosts where the underlying future chain could surface an error synchronously.
• perf: Async.value skips an unnecessary Future.value(...) wrap for Async.new-constructed instances.
• perf: combineResult(...) fast path skips the materialized-list allocation when no onErr aggregator is configured.
• perf: many hot helpers (combineOutcome, flatten, named, noneIfEmpty, iterable filters, SafeCompleter.resolvable, task-batch queue methods) gained @pragma('vm:prefer-inline') and shed per-call closure allocations.
• Outcome.raw(...) is now annotated @unsafeOrError — df_safer_dart_lints will flag direct call sites that aren't inside an UNSAFE(...) block. Use rawSync / rawAsync for the safe variants.
• Sync/Async constructors and toAsync / toSync / UNSAFE / asyncSome assertions now correctly allow Never type arguments.

0.20.0

• breaking: Outcome.end() now returns void everywhere (previously FutureOr<void>, with Async.end() returning Future<void>). Calling .end() is the "intentionally discarding this Outcome" marker — there is no longer a Future to await. Async.end() detaches its internal cleanup via unawaited(...). If you actually need the async value, use .value.