Use ConfigureAwait(false) on await foreach in ExtractorBase and TransformerBase

CHANGELOG.md

@@ -21,9 +21,18 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## [0.22.0] - 2026-08-04
 
-Repository consolidation only — the `Wolfgang.Etl.TestKit` and `Wolfgang.Etl.TestKit.Xunit` packages now
-build and release from this repository. **No public API change** to any of the four packages; a
-release-source move, not a behavioural change.
+Repository consolidation — the `Wolfgang.Etl.TestKit` and `Wolfgang.Etl.TestKit.Xunit` packages now
+build and release from this repository. **No public API change** to any of the four packages. The
+consolidation itself is a release-source move; it ships alongside one behavioural fix, noted below.
+
+### Fixed
+
+- **`await foreach` in `ExtractorBase` and `TransformerBase` now uses `ConfigureAwait(false)`.** Four
+  sites (`ExtractorBase.ExtractAsync` / `ExtractWithProgressAsync`, `TransformerBase.TransformAsync` /
+  `TransformWithProgressAsync`) resumed on the captured synchronization context, a deadlock risk for
+  consumers calling sync-over-async on the `net462` and `netstandard2.0` targets. `CA2007` does not
+  analyse `await foreach`, so this was invisible to the analyzer gate; the rest of the package already
+  used `ConfigureAwait(false)` at every other `await foreach`.
 
 ### Changed
 

src/Wolfgang.Etl.Abstractions/ExtractorBase.cs

@@ -323,7 +323,7 @@ [EnumeratorCancellation] CancellationToken token
     {
         ResetRunState();
 
-        await foreach (var item in WrapWorkerExecution(ExtractWorkerAsync, token))
+        await foreach (var item in WrapWorkerExecution(ExtractWorkerAsync, token).ConfigureAwait(false))
         {
             yield return item;
         }
@@ -341,7 +341,7 @@ private async IAsyncEnumerable<TSource> ExtractWithProgressAsync(
 
         try
         {
-            await foreach (var item in WrapWorkerExecution(ExtractWorkerAsync, token))
+            await foreach (var item in WrapWorkerExecution(ExtractWorkerAsync, token).ConfigureAwait(false))
             {
                 yield return item;
             }

src/Wolfgang.Etl.Abstractions/TransformerBase.cs

@@ -331,7 +331,7 @@ [EnumeratorCancellation] CancellationToken token
     {
         ResetRunState();
 
-        await foreach (var item in WrapWorkerExecution(ct => TransformWorkerAsync(items, ct), token))
+        await foreach (var item in WrapWorkerExecution(ct => TransformWorkerAsync(items, ct), token).ConfigureAwait(false))
         {
             yield return item;
         }
@@ -349,7 +349,7 @@ private async IAsyncEnumerable<TDestination> TransformWithProgressAsync(
 
         try
         {
-            await foreach (var item in WrapWorkerExecution(ct => TransformWorkerAsync(items, ct), token))
+            await foreach (var item in WrapWorkerExecution(ct => TransformWorkerAsync(items, ct), token).ConfigureAwait(false))
             {
                 yield return item;
             }