Inconsistency in generic function type equality between Dart VM and webdev

[vincentvanpeer]

Dart 2.0.0-dev.69.0 (Unknown timestamp) on "linux_x64"

https://github.com/vincentvanpeer/dartfunctiongenericbug contains a method that prints the equality between a type def and a generic type, which in the implementation of both the test and the webapp, contains the same type def.

When running the unit test, both in the VM and in Chrome, I get the same expected result.

$ pub run test
00:01 +0: loading test/lib_test.dart                                                                                                                                                                                                                          
T == MyFunction: true
No tests ran.
$ pub run test -p chrome
00:07 +0: compiling test/lib_test.dart                                                                                                                                                                                                                        
Compiled 8,664,184 characters Dart to 939,849 characters JavaScript in 7.07 seconds
Dart file (/tmp/dart_test_IEORVD/runInBrowser.dart) compiled to JavaScript: /tmp/dart_test_CIQGJI/test_ECSRIO/lib_test.dart.browser_test.dart.js

T == MyFunction: true
No tests ran.

However if I run the web code in Chrome, as shown below, the console prints T == MyFunction: false

$ pub global run webdev serve
[INFO] Setting up file watchers completed, took 31ms
[INFO] Waiting for all file watchers to be ready completed, took 49ms
[INFO] Building new asset graph completed, took 880ms
[INFO] Checking for unexpected pre-existing outputs. completed, took 1ms
[INFO] Running build completed, took 3.9s
[INFO] Caching finalized dependency graph completed, took 161ms
[INFO] Succeeded after 4.1s with 14 outputs (1503 actions)
Serving `web` on http://localhost:8080
Serving `test` on http://localhost:8081

This is inconsistent. I would expect the condition to return true in Chrome as well.

[natebosch]

dart2js, vm, and ddc all agree on this now. Equality is based on the function type, not the typedef name.

[eernstg]

Note that the test mentioned here is a less comprehensive version of the one mentioned in #32782, which is still open (and tests/language_2/type_alias_equality_test.dart incurs a run-time error where it shouldn't, for at least several configurations of the vm).