fixes #27586, prefer context type in generic inference

pkg/dev_compiler/tool/sdk_expected_errors.txt

Index: pkg/dev_compiler/tool/sdk_expected_errors.txt
diff --git a/pkg/dev_compiler/tool/sdk_expected_errors.txt b/pkg/dev_compiler/tool/sdk_expected_errors.txt
index f944799c9d82ba9b3840e51776204c2798f47f80..3ccb3fc926154d4842ddc0a5a00946e2904d5416 100644
--- a/pkg/dev_compiler/tool/sdk_expected_errors.txt
+++ b/pkg/dev_compiler/tool/sdk_expected_errors.txt
@@ -1,5 +1,14 @@
-[error] Couldn't infer type parameter 'T'; '_ControllerEventSinkWrapper<dynamic>' must be of type 'EventSink<T>'. (dart:async/stream.dart, line 1359, col 16)
-[error] The argument type '_ControllerEventSinkWrapper' can't be assigned to the parameter type 'EventSink<T>'. (dart:async/stream.dart, line 1359, col 53)
+[error] Couldn't infer type parameter 'T'.
+
+Inferred type '_ControllerEventSinkWrapper<dynamic>' does not work with constraints:
+  Argument 'action' inferred as '(EventSink<T>) → dynamic' must be a '(T) → R'.
+The type '_ControllerEventSinkWrapper<dynamic>' was inferred from:
+  Argument 'argument' inferred as '_ControllerEventSinkWrapper<dynamic>' must be a 'T'.
+
+Consider passing explicit type argument(s) to the generic.
+
+ (dart:async/stream.dart, line 1359, col 16)
+[error] The argument type 'ZoneUnaryCallback(EventSink<T>) → dynamic' can't be assigned to the parameter type '(_ControllerEventSinkWrapper<dynamic>) → dynamic'. (dart:async/stream.dart, line 1359, col 32)
 [error] Type parameter bound types must be instantiated. (dart:collection/queue.dart, line 99, col 32)
 [error] Invalid override. The type of '_UnicodeSubsetEncoder.startChunkedConversion' ('(Sink<List<int>>) → StringConversionSink') isn't a subtype of 'ChunkedConverter<String, List<int>, String, List<int>>.startChunkedConversion' ('(dynamic) → dynamic'). (dart:convert/ascii.dart, line 107, col 3)
 [error] Invalid override. The type of '_UnicodeSubsetEncoder.bind' ('(Stream<String>) → Stream<List<int>>') isn't a subtype of 'ChunkedConverter<String, List<int>, String, List<int>>.bind' ('(dynamic) → dynamic'). (dart:convert/ascii.dart, line 115, col 3)
@@ -39,7 +48,7 @@
 [error] Base class introduces an invalid override. The type of 'Converter.bind' ('(Stream<List<int>>) → Stream<List<int>>') isn't a subtype of 'ChunkedConverter<List<int>, List<int>, List<int>, List<int>>.bind' ('(dynamic) → dynamic'). (dart:io/data_transformer.dart, line 278, col 19)
 [error] Invalid override. The type of 'ZLibEncoder.startChunkedConversion' ('(Sink<List<int>>) → ByteConversionSink') isn't a subtype of 'ChunkedConverter<List<int>, List<int>, List<int>, List<int>>.startChunkedConversion' ('(dynamic) → dynamic'). (dart:io/data_transformer.dart, line 370, col 3)
 [error] The argument type '(RandomAccessFile) → Future<RandomAccessFile>' can't be assigned to the parameter type '(RandomAccessFile) → FutureOr<File>'. (dart:io/file_impl.dart, line 216, col 30)
-[error] The return type 'Future' isn't a 'FutureOr<File>', as defined by the method ''. (dart:io/file_impl.dart, line 614, col 14)
+[error] The return type 'Future<Object>' isn't a 'FutureOr<File>', as defined by the method ''. (dart:io/file_impl.dart, line 614, col 14)
 [error] Undefined name 'lineMode'. (dart:io/stdio.dart, line 64, col 10)
 [error] The name 'echoMode=' is already defined. (dart:io/stdio.dart, line 128, col 12)
 [error] The name 'lineMode=' is already defined. (dart:io/stdio.dart, line 149, col 12)
@@ -47,90 +56,91 @@
 [error] Invalid override. The type of '_WindowsCodePageEncoder.startChunkedConversion' ('(Sink<List<int>>) → StringConversionSink') isn't a subtype of 'ChunkedConverter<String, List<int>, String, List<int>>.startChunkedConversion' ('(dynamic) → dynamic'). (dart:io/string_transformer.dart, line 61, col 3)
 [error] Base class introduces an invalid override. The type of 'Converter.bind' ('(Stream<List<int>>) → Stream<String>') isn't a subtype of 'ChunkedConverter<List<int>, String, List<int>, String>.bind' ('(dynamic) → dynamic'). (dart:io/string_transformer.dart, line 100, col 31)
 [error] Invalid override. The type of '_WindowsCodePageDecoder.startChunkedConversion' ('(Sink<String>) → ByteConversionSink') isn't a subtype of 'ChunkedConverter<List<int>, String, List<int>, String>.startChunkedConversion' ('(dynamic) → dynamic'). (dart:io/string_transformer.dart, line 112, col 3)
-[error] The getter 'packagesBase' isn't defined for the class 'IsolateNatives'. (dart:isolate, line 721, col 61)
-[error] Invalid override. The type of 'JsArray.[]=' ('(Object, E) → void') isn't a subtype of 'JsObject.[]=' ('(Object, dynamic) → dynamic'). (dart:js, line 363, col 3)
+[error] The getter 'packagesBase' isn't defined for the class 'IsolateNatives'. (dart:isolate, line 716, col 61)
+[error] Invalid override. The type of 'JsArray.[]=' ('(Object, E) → void') isn't a subtype of 'JsObject.[]=' ('(Object, dynamic) → dynamic'). (dart:js, line 370, col 3)
+[error] The argument type 'List' can't be assigned to the parameter type 'Iterable<Null>'. (dart:js_util, line 112, col 29)
 [error] The return type 'double' isn't a 'T', as defined by the method 'min'. (dart:math, line 90, col 16)
 [error] The return type 'double' isn't a 'T', as defined by the method 'max'. (dart:math, line 125, col 16)
-[warning] The final variable 'origin' must be initialized. (dart:html, line 177, col 3)
-[warning] The final variable 'origin' must be initialized. (dart:html, line 813, col 3)
-[warning] The final variables 'form', 'labels' and '3' more must be initialized. (dart:html, line 1691, col 3)
-[warning] The final variable 'options' must be initialized. (dart:html, line 8972, col 3)
-[warning] The final variables '_attributes', '_childElementCount' and '16' more must be initialized. (dart:html, line 13009, col 3)
-[warning] The final variables 'elements', 'form' and '4' more must be initialized. (dart:html, line 16625, col 3)
-[warning] The final variable 'length' must be initialized. (dart:html, line 17555, col 3)
-[warning] The final variables '_get_contentWindow' and 'sandbox' must be initialized. (dart:html, line 20113, col 3)
-[warning] The final variables 'complete', 'currentSrc' and '2' more must be initialized. (dart:html, line 20246, col 3)
-[warning] The final variables '_get_valueAsDate', 'entries' and '6' more must be initialized. (dart:html, line 20400, col 3)
-[warning] The final variables 'form', 'labels' and '4' more must be initialized. (dart:html, line 21436, col 3)
-[warning] The final variables 'control' and 'form' must be initialized. (dart:html, line 21547, col 3)
-[warning] The final variable 'form' must be initialized. (dart:html, line 21581, col 3)
-[warning] The final variables 'import', 'sheet' and '1' more must be initialized. (dart:html, line 21607, col 3)
-[warning] The final variable 'areas' must be initialized. (dart:html, line 21759, col 3)
-[warning] The final variables 'audioDecodedByteCount', 'audioTracks' and '16' more must be initialized. (dart:html, line 21985, col 3)
-[warning] The final variable 'labels' must be initialized. (dart:html, line 23501, col 3)
-[warning] The final variables '_localName', '_namespaceUri' and '12' more must be initialized. (dart:html, line 24939, col 3)
-[warning] The final variables 'form', 'validationMessage' and '2' more must be initialized. (dart:html, line 25820, col 3)
-[warning] The final variables 'form' and 'index' must be initialized. (dart:html, line 25955, col 3)
-[warning] The final variables 'form', 'htmlFor' and '5' more must be initialized. (dart:html, line 26009, col 3)
-[warning] The final variables 'labels' and 'position' must be initialized. (dart:html, line 27415, col 3)
-[warning] The final variables 'form', 'labels' and '4' more must be initialized. (dart:html, line 29186, col 3)
-[warning] The final variable 'sheet' must be initialized. (dart:html, line 31442, col 3)
-[warning] The final variable 'cellIndex' must be initialized. (dart:html, line 31662, col 3)
-[warning] The final variables '_rows' and '_tBodies' must be initialized. (dart:html, line 31773, col 3)
-[warning] The final variables '_cells', 'rowIndex' and '1' more must be initialized. (dart:html, line 31883, col 3)
-[warning] The final variable '_rows' must be initialized. (dart:html, line 31950, col 3)
-[warning] The final variable 'content' must be initialized. (dart:html, line 31993, col 3)
-[warning] The final variables 'form', 'labels' and '5' more must be initialized. (dart:html, line 32069, col 3)
-[warning] The final variables 'readyState' and 'track' must be initialized. (dart:html, line 33056, col 3)
-[warning] The final variables 'decodedFrameCount', 'droppedFrameCount' and '2' more must be initialized. (dart:html, line 33754, col 3)
-[warning] The final variables 'href' and 'target' must be initialized. (dart:svg, line 60, col 3)
-[warning] The final variables 'requiredExtensions', 'requiredFeatures' and '2' more must be initialized. (dart:svg, line 489, col 3)
-[warning] The final variables 'cx', 'cy' and '1' more must be initialized. (dart:svg, line 562, col 3)
-[warning] The final variable 'clipPathUnits' must be initialized. (dart:svg, line 597, col 3)
-[warning] The final variables 'cx', 'cy' and '2' more must be initialized. (dart:svg, line 689, col 3)
-[warning] The final variables 'height', 'in1' and '6' more must be initialized. (dart:svg, line 732, col 3)
-[warning] The final variables 'height', 'in1' and '6' more must be initialized. (dart:svg, line 820, col 3)
-[warning] The final variables 'height', 'in1' and '4' more must be initialized. (dart:svg, line 904, col 3)
-[warning] The final variables 'height', 'in1' and '10' more must be initialized. (dart:svg, line 952, col 3)
-[warning] The final variables 'bias', 'divisor' and '15' more must be initialized. (dart:svg, line 1057, col 3)
-[warning] The final variables 'diffuseConstant', 'height' and '8' more must be initialized. (dart:svg, line 1173, col 3)
-[warning] The final variables 'height', 'in1' and '8' more must be initialized. (dart:svg, line 1245, col 3)
-[warning] The final variables 'azimuth' and 'elevation' must be initialized. (dart:svg, line 1337, col 3)
-[warning] The final variables 'height', 'result' and '3' more must be initialized. (dart:svg, line 1375, col 3)
-[warning] The final variables 'height', 'in1' and '6' more must be initialized. (dart:svg, line 1547, col 3)
-[warning] The final variables 'height', 'href' and '5' more must be initialized. (dart:svg, line 1615, col 3)
-[warning] The final variables 'height', 'result' and '3' more must be initialized. (dart:svg, line 1677, col 3)
-[warning] The final variable 'in1' must be initialized. (dart:svg, line 1729, col 3)
-[warning] The final variables 'height', 'in1' and '7' more must be initialized. (dart:svg, line 1759, col 3)
-[warning] The final variables 'dx', 'dy' and '6' more must be initialized. (dart:svg, line 1836, col 3)
-[warning] The final variables 'x', 'y' and '1' more must be initialized. (dart:svg, line 1900, col 3)
-[warning] The final variables 'height', 'in1' and '9' more must be initialized. (dart:svg, line 1942, col 3)
-[warning] The final variables 'limitingConeAngle', 'pointsAtX' and '6' more must be initialized. (dart:svg, line 2020, col 3)
-[warning] The final variables 'height', 'in1' and '4' more must be initialized. (dart:svg, line 2082, col 3)
-[warning] The final variables 'baseFrequencyX', 'baseFrequencyY' and '9' more must be initialized. (dart:svg, line 2138, col 3)
-[warning] The final variables 'filterUnits', 'height' and '5' more must be initialized. (dart:svg, line 2238, col 3)
-[warning] The final variables 'height', 'width' and '2' more must be initialized. (dart:svg, line 2335, col 3)
-[warning] The final variables 'farthestViewportElement', 'nearestViewportElement' and '4' more must be initialized. (dart:svg, line 2425, col 3)
-[warning] The final variables 'height', 'href' and '4' more must be initialized. (dart:svg, line 2507, col 3)
-[warning] The final variables 'x1', 'x2' and '2' more must be initialized. (dart:svg, line 2736, col 3)
-[warning] The final variables 'x1', 'x2' and '2' more must be initialized. (dart:svg, line 2775, col 3)
-[warning] The final variables 'markerHeight', 'markerUnits' and '7' more must be initialized. (dart:svg, line 2814, col 3)
-[warning] The final variables 'height', 'maskContentUnits' and '7' more must be initialized. (dart:svg, line 2907, col 3)
-[warning] The final variables 'animatedNormalizedPathSegList', 'animatedPathSegList' and '3' more must be initialized. (dart:svg, line 3188, col 3)
-[warning] The final variables 'height', 'href' and '11' more must be initialized. (dart:svg, line 4017, col 3)
-[warning] The final variables 'animatedPoints' and 'points' must be initialized. (dart:svg, line 4182, col 3)
-[warning] The final variables 'animatedPoints' and 'points' must be initialized. (dart:svg, line 4213, col 3)
-[warning] The final variables 'cx', 'cy' and '4' more must be initialized. (dart:svg, line 4321, col 3)
-[warning] The final variables 'height', 'rx' and '4' more must be initialized. (dart:svg, line 4397, col 3)
-[warning] The final variable 'href' must be initialized. (dart:svg, line 4444, col 3)
-[warning] The final variable 'gradientOffset' must be initialized. (dart:svg, line 4506, col 3)
-[warning] The final variable 'sheet' must be initialized. (dart:svg, line 4634, col 3)
-[warning] The final variables 'ownerSvgElement' and 'viewportElement' must be initialized. (dart:svg, line 5072, col 3)
-[warning] The final variables 'currentTranslate', 'currentView' and '12' more must be initialized. (dart:svg, line 5386, col 3)
-[warning] The final variables 'preserveAspectRatio' and 'viewBox' must be initialized. (dart:svg, line 5605, col 3)
-[warning] The final variables 'lengthAdjust' and 'textLength' must be initialized. (dart:svg, line 5677, col 3)
-[warning] The final variables 'href', 'method' and '2' more must be initialized. (dart:svg, line 5775, col 3)
-[warning] The final variables 'dx', 'dy' and '3' more must be initialized. (dart:svg, line 5836, col 3)
-[warning] The final variables 'height', 'href' and '3' more must be initialized. (dart:svg, line 6126, col 3)
-[warning] The final variables 'preserveAspectRatio', 'viewBox' and '1' more must be initialized. (dart:svg, line 6171, col 3)
-[warning] The final variables 'gradientTransform', 'gradientUnits' and '2' more must be initialized. (dart:svg, line 6325, col 3)
+[warning] The final variable 'origin' must be initialized. (dart:html, line 187, col 3)
+[warning] The final variable 'origin' must be initialized. (dart:html, line 853, col 3)
+[warning] The final variables 'form', 'labels' and '3' more must be initialized. (dart:html, line 1775, col 3)
+[warning] The final variable 'options' must be initialized. (dart:html, line 8922, col 3)
+[warning] The final variables '_attributes', '_childElementCount' and '16' more must be initialized. (dart:html, line 13164, col 3)
+[warning] The final variables 'elements', 'form' and '4' more must be initialized. (dart:html, line 16932, col 3)
+[warning] The final variable 'length' must be initialized. (dart:html, line 17898, col 3)
+[warning] The final variables '_get_contentWindow' and 'sandbox' must be initialized. (dart:html, line 20564, col 3)
+[warning] The final variables 'complete', 'currentSrc' and '2' more must be initialized. (dart:html, line 20703, col 3)
+[warning] The final variables '_get_valueAsDate', 'entries' and '6' more must be initialized. (dart:html, line 20860, col 3)
+[warning] The final variables 'form', 'labels' and '4' more must be initialized. (dart:html, line 21927, col 3)
+[warning] The final variables 'control' and 'form' must be initialized. (dart:html, line 22042, col 3)
+[warning] The final variable 'form' must be initialized. (dart:html, line 22077, col 3)
+[warning] The final variables 'import', 'sheet' and '1' more must be initialized. (dart:html, line 22104, col 3)
+[warning] The final variable 'areas' must be initialized. (dart:html, line 22256, col 3)
+[warning] The final variables 'audioDecodedByteCount', 'audioTracks' and '16' more must be initialized. (dart:html, line 22492, col 3)
+[warning] The final variable 'labels' must be initialized. (dart:html, line 24089, col 3)
+[warning] The final variables '_localName', '_namespaceUri' and '12' more must be initialized. (dart:html, line 25631, col 3)
+[warning] The final variables 'form', 'validationMessage' and '2' more must be initialized. (dart:html, line 26532, col 3)
+[warning] The final variables 'form' and 'index' must be initialized. (dart:html, line 26678, col 3)
+[warning] The final variables 'form', 'htmlFor' and '5' more must be initialized. (dart:html, line 26732, col 3)
+[warning] The final variables 'labels' and 'position' must be initialized. (dart:html, line 28207, col 3)
+[warning] The final variables 'form', 'labels' and '4' more must be initialized. (dart:html, line 30128, col 3)
+[warning] The final variable 'sheet' must be initialized. (dart:html, line 32489, col 3)
+[warning] The final variable 'cellIndex' must be initialized. (dart:html, line 32719, col 3)
+[warning] The final variables '_rows' and '_tBodies' must be initialized. (dart:html, line 32830, col 3)
+[warning] The final variables '_cells', 'rowIndex' and '1' more must be initialized. (dart:html, line 32943, col 3)
+[warning] The final variable '_rows' must be initialized. (dart:html, line 33012, col 3)
+[warning] The final variable 'content' must be initialized. (dart:html, line 33056, col 3)
+[warning] The final variables 'form', 'labels' and '5' more must be initialized. (dart:html, line 33132, col 3)
+[warning] The final variables 'readyState' and 'track' must be initialized. (dart:html, line 34173, col 3)
+[warning] The final variables 'decodedFrameCount', 'droppedFrameCount' and '2' more must be initialized. (dart:html, line 34889, col 3)
+[warning] The final variables 'href' and 'target' must be initialized. (dart:svg, line 56, col 3)
+[warning] The final variables 'requiredExtensions', 'requiredFeatures' and '2' more must be initialized. (dart:svg, line 512, col 3)
+[warning] The final variables 'cx', 'cy' and '1' more must be initialized. (dart:svg, line 587, col 3)
+[warning] The final variable 'clipPathUnits' must be initialized. (dart:svg, line 624, col 3)
+[warning] The final variables 'cx', 'cy' and '2' more must be initialized. (dart:svg, line 723, col 3)
+[warning] The final variables 'height', 'in1' and '6' more must be initialized. (dart:svg, line 769, col 3)
+[warning] The final variables 'height', 'in1' and '6' more must be initialized. (dart:svg, line 862, col 3)
+[warning] The final variables 'height', 'in1' and '4' more must be initialized. (dart:svg, line 951, col 3)
+[warning] The final variables 'height', 'in1' and '10' more must be initialized. (dart:svg, line 1003, col 3)
+[warning] The final variables 'bias', 'divisor' and '15' more must be initialized. (dart:svg, line 1111, col 3)
+[warning] The final variables 'diffuseConstant', 'height' and '8' more must be initialized. (dart:svg, line 1232, col 3)
+[warning] The final variables 'height', 'in1' and '8' more must be initialized. (dart:svg, line 1309, col 3)
+[warning] The final variables 'azimuth' and 'elevation' must be initialized. (dart:svg, line 1405, col 3)
+[warning] The final variables 'height', 'result' and '3' more must be initialized. (dart:svg, line 1448, col 3)
+[warning] The final variables 'height', 'in1' and '6' more must be initialized. (dart:svg, line 1641, col 3)
+[warning] The final variables 'height', 'href' and '5' more must be initialized. (dart:svg, line 1714, col 3)
+[warning] The final variables 'height', 'result' and '3' more must be initialized. (dart:svg, line 1781, col 3)
+[warning] The final variable 'in1' must be initialized. (dart:svg, line 1837, col 3)
+[warning] The final variables 'height', 'in1' and '7' more must be initialized. (dart:svg, line 1871, col 3)
+[warning] The final variables 'dx', 'dy' and '6' more must be initialized. (dart:svg, line 1951, col 3)
+[warning] The final variables 'x', 'y' and '1' more must be initialized. (dart:svg, line 2019, col 3)
+[warning] The final variables 'height', 'in1' and '9' more must be initialized. (dart:svg, line 2066, col 3)
+[warning] The final variables 'limitingConeAngle', 'pointsAtX' and '6' more must be initialized. (dart:svg, line 2148, col 3)
+[warning] The final variables 'height', 'in1' and '4' more must be initialized. (dart:svg, line 2215, col 3)
+[warning] The final variables 'baseFrequencyX', 'baseFrequencyY' and '9' more must be initialized. (dart:svg, line 2276, col 3)
+[warning] The final variables 'filterUnits', 'height' and '5' more must be initialized. (dart:svg, line 2380, col 3)
+[warning] The final variables 'height', 'width' and '2' more must be initialized. (dart:svg, line 2483, col 3)
+[warning] The final variables 'farthestViewportElement', 'nearestViewportElement' and '4' more must be initialized. (dart:svg, line 2578, col 3)
+[warning] The final variables 'height', 'href' and '4' more must be initialized. (dart:svg, line 2662, col 3)
+[warning] The final variables 'x1', 'x2' and '2' more must be initialized. (dart:svg, line 2896, col 3)
+[warning] The final variables 'x1', 'x2' and '2' more must be initialized. (dart:svg, line 2937, col 3)
+[warning] The final variables 'markerHeight', 'markerUnits' and '7' more must be initialized. (dart:svg, line 2978, col 3)
+[warning] The final variables 'height', 'maskContentUnits' and '7' more must be initialized. (dart:svg, line 3073, col 3)
+[warning] The final variables 'animatedNormalizedPathSegList', 'animatedPathSegList' and '3' more must be initialized. (dart:svg, line 3361, col 3)
+[warning] The final variables 'height', 'href' and '11' more must be initialized. (dart:svg, line 4225, col 3)
+[warning] The final variables 'animatedPoints' and 'points' must be initialized. (dart:svg, line 4394, col 3)
+[warning] The final variables 'animatedPoints' and 'points' must be initialized. (dart:svg, line 4427, col 3)
+[warning] The final variables 'cx', 'cy' and '4' more must be initialized. (dart:svg, line 4538, col 3)
+[warning] The final variables 'height', 'rx' and '4' more must be initialized. (dart:svg, line 4617, col 3)
+[warning] The final variable 'href' must be initialized. (dart:svg, line 4666, col 3)
+[warning] The final variable 'gradientOffset' must be initialized. (dart:svg, line 4734, col 3)
+[warning] The final variable 'sheet' must be initialized. (dart:svg, line 4866, col 3)
+[warning] The final variables 'ownerSvgElement' and 'viewportElement' must be initialized. (dart:svg, line 5354, col 3)
+[warning] The final variables 'currentTranslate', 'currentView' and '12' more must be initialized. (dart:svg, line 5676, col 3)
+[warning] The final variables 'preserveAspectRatio' and 'viewBox' must be initialized. (dart:svg, line 5899, col 3)
+[warning] The final variables 'lengthAdjust' and 'textLength' must be initialized. (dart:svg, line 5975, col 3)
+[warning] The final variables 'href', 'method' and '2' more must be initialized. (dart:svg, line 6076, col 3)
+[warning] The final variables 'dx', 'dy' and '3' more must be initialized. (dart:svg, line 6138, col 3)
+[warning] The final variables 'height', 'href' and '3' more must be initialized. (dart:svg, line 6437, col 3)
+[warning] The final variables 'preserveAspectRatio', 'viewBox' and '1' more must be initialized. (dart:svg, line 6484, col 3)
+[warning] The final variables 'gradientTransform', 'gradientUnits' and '2' more must be initialized. (dart:svg, line 6642, col 3)