Bug 215909

Description:
streams/reference-implementation/transform-stream-errors.html
streams/reference-implementation/transform-stream.html

The first failure that I see this on the dashboard was 08/27/20 at r266230.
This change in https://trac.webkit.org/changeset/266228 seems to have introduced the failure.

The test was expecting assert_equals: writable starts in writable expected (string) "writable" but got (undefined), but receiving Can't find variable: TransformStream

History:
https://results.webkit.org/?suite=layout-tests&test=streams%2Freference-implementation%2Ftransform-stream-errors.html&version_name=Win10&platform=wincairo&limit=50000

Test 1: 
streams/reference-implementation/transform-stream-errors.html
Diff Log:
--- /home/buildbot/worker/Windows-EWS/build/layout-test-results/streams/reference-implementation/transform-stream-errors-expected.txt
+++ /home/buildbot/worker/Windows-EWS/build/layout-test-results/streams/reference-implementation/transform-stream-errors-actual.txt
@@ -1,4 +1,4 @@
 
-FAIL TransformStream errors thrown in transform put the writable and readable in an errored state assert_equals: writable starts in writable expected (string) "writable" but got (undefined) undefined
-FAIL TransformStream errors thrown in flush put the writable and readable in an errored state undefined is not an object (evaluating 'ts.writable.closed.then')
+FAIL TransformStream errors thrown in transform put the writable and readable in an errored state Can't find variable: TransformStream
+FAIL TransformStream errors thrown in flush put the writable and readable in an errored state Can't find variable: TransformStream

Test 2: 
streams/reference-implementation/transform-stream.html
Diff Log:

--- /home/buildbot/worker/Windows-EWS/build/layout-test-results/streams/reference-implementation/transform-stream-expected.txt
+++ /home/buildbot/worker/Windows-EWS/build/layout-test-results/streams/reference-implementation/transform-stream-actual.txt
@@ -1,20 +1,20 @@
 
-PASS TransformStream can be constructed with a transform function 
-FAIL TransformStream cannot be constructed with no transform function assert_throws: TransformStream cannot be constructed with no arguments function "function () { new TransformStream(); }" did not throw
-FAIL TransformStream instances must have writable and readable properties of the correct types assert_true: it has a writable property expected true got false
-FAIL TransformStream writable starts in the writable state assert_equals: writable starts writable expected (string) "writable" but got (undefined) undefined
-FAIL Pass-through sync TransformStream: can read from readable what is put into writable ts.writable.write is not a function. (In 'ts.writable.write('a')', 'ts.writable.write' is undefined)
-FAIL Uppercaser sync TransformStream: can read from readable transformed version of what is put into writable ts.writable.write is not a function. (In 'ts.writable.write('a')', 'ts.writable.write' is undefined)
-FAIL Uppercaser-doubler sync TransformStream: can read both chunks put into the readable ts.writable.write is not a function. (In 'ts.writable.write('a')', 'ts.writable.write' is undefined)
-FAIL Uppercaser async TransformStream: can read from readable transformed version of what is put into writable ts.writable.write is not a function. (In 'ts.writable.write('a')', 'ts.writable.write' is undefined)
-FAIL Uppercaser-doubler async TransformStream: can read both chunks put into the readable ts.writable.write is not a function. (In 'ts.writable.write('a')', 'ts.writable.write' is undefined)
-FAIL TransformStream: by default, closing the writable closes the readable (when there are no queued writes) assert_equals: writable is closing expected (string) "closing" but got (undefined) undefined
-FAIL TransformStream: by default, closing the writable waits for transforms to finish before closing both ts.writable.write is not a function. (In 'ts.writable.write('a')', 'ts.writable.write' is undefined)
-FAIL TransformStream: by default, closing the writable closes the readable after sync enqueues and async done ts.writable.write is not a function. (In 'ts.writable.write('a')', 'ts.writable.write' is undefined)
-FAIL TransformStream: by default, closing the writable closes the readable after async enqueues and async done ts.writable.write is not a function. (In 'ts.writable.write('a')', 'ts.writable.write' is undefined)
-PASS TransformStream flush is called immediately when the writable is closed, if no writes are queued 
-FAIL TransformStream flush is called after all queued writes finish, once the writable is closed ts.writable.write is not a function. (In 'ts.writable.write('a')', 'ts.writable.write' is undefined)
-FAIL TransformStream flush gets a chance to enqueue more into the readable ts.writable.write is not a function. (In 'ts.writable.write('a')', 'ts.writable.write' is undefined)
-FAIL TransformStream flush gets a chance to enqueue more into the readable, and can then async close ts.writable.write is not a function. (In 'ts.writable.write('a')', 'ts.writable.write' is undefined)
-FAIL Transform stream should call transformer methods as methods ts.writable.write is not a function. (In 'ts.writable.write('a')', 'ts.writable.write' is undefined)
+FAIL TransformStream can be constructed with a transform function Can't find variable: TransformStream
+FAIL TransformStream cannot be constructed with no transform function assert_throws: TransformStream cannot be constructed with no arguments function "function () { new TransformStream(); }" threw object "ReferenceError: Can't find variable: TransformStream" ("ReferenceError") expected object "TypeError" ("TypeError")
+FAIL TransformStream instances must have writable and readable properties of the correct types Can't find variable: TransformStream
+FAIL TransformStream writable starts in the writable state Can't find variable: TransformStream
+FAIL Pass-through sync TransformStream: can read from readable what is put into writable Can't find variable: TransformStream
+FAIL Uppercaser sync TransformStream: can read from readable transformed version of what is put into writable Can't find variable: TransformStream
+FAIL Uppercaser-doubler sync TransformStream: can read both chunks put into the readable Can't find variable: TransformStream
+FAIL Uppercaser async TransformStream: can read from readable transformed version of what is put into writable Can't find variable: TransformStream
+FAIL Uppercaser-doubler async TransformStream: can read both chunks put into the readable Can't find variable: TransformStream
+FAIL TransformStream: by default, closing the writable closes the readable (when there are no queued writes) Can't find variable: TransformStream
+FAIL TransformStream: by default, closing the writable waits for transforms to finish before closing both Can't find variable: TransformStream
+FAIL TransformStream: by default, closing the writable closes the readable after sync enqueues and async done Can't find variable: TransformStream
+FAIL TransformStream: by default, closing the writable closes the readable after async enqueues and async done Can't find variable: TransformStream
+FAIL TransformStream flush is called immediately when the writable is closed, if no writes are queued Can't find variable: TransformStream
+FAIL TransformStream flush is called after all queued writes finish, once the writable is closed Can't find variable: TransformStream
+FAIL TransformStream flush gets a chance to enqueue more into the readable Can't find variable: TransformStream
+FAIL TransformStream flush gets a chance to enqueue more into the readable, and can then async close Can't find variable: TransformStream
+FAIL Transform stream should call transformer methods as methods Can't find variable: TransformStream