Fix33448

[Anders Hejlsberg (ahejlsberg)]

Fixes#33448. Also fixes the issue in #33498 (comment).

This PR supercedes #33498. (Thanks Jack Williams (@jack-williams)!)

[Anders Hejlsberg (ahejlsberg)]

TypeScript Bot (@typescript-bot) test this
TypeScript Bot (@typescript-bot) user test this
TypeScript Bot (@typescript-bot) run dt
TypeScript Bot (@typescript-bot) perf test this

[TypeScript Bot (typescript-bot)]

Heya Anders Hejlsberg (@ahejlsberg), I've started to run the parallelized Definitely Typed test suite on this PR at 6bc8b12. You can monitor the build here. It should now contribute to this PR's status checks.

[TypeScript Bot (typescript-bot)]

Heya Anders Hejlsberg (@ahejlsberg), I've started to run the extended test suite on this PR at 6bc8b12. You can monitor the build here. It should now contribute to this PR's status checks.

[TypeScript Bot (typescript-bot)]

Heya Anders Hejlsberg (@ahejlsberg), I've started to run the parallelized community code test suite on this PR at 6bc8b12. You can monitor the build here. It should now contribute to this PR's status checks.

[TypeScript Bot (typescript-bot)]

Heya Anders Hejlsberg (@ahejlsberg), I've started to run the perf test suite on this PR at 6bc8b12. You can monitor the build here. It should now contribute to this PR's status checks.

Update: The results are in!

[TypeScript Bot (typescript-bot)]

Anders Hejlsberg (@ahejlsberg)
The results of the perf run you requested are in!

Here they are:

Comparison Report - master..35513

Metric	master	35513	Delta	Best	Worst
Angular - node (v10.16.3, x64)
Memory used	354,807k (± 0.02%)	356,542k (± 0.02%)	+1,736k (+ 0.49%)	356,315k	356,620k
Parse Time	1.61s (± 0.60%)	1.63s (± 0.35%)	+0.02s (+ 1.31%)	1.62s	1.64s
Bind Time	0.86s (± 0.95%)	0.86s (± 0.77%)	+0.00s (+ 0.35%)	0.85s	0.87s
Check Time	4.53s (± 0.27%)	4.53s (± 0.61%)	+0.01s (+ 0.13%)	4.49s	4.60s
Emit Time	5.25s (± 0.47%)	5.22s (± 0.71%)	-0.02s (- 0.38%)	5.16s	5.31s
Total Time	12.24s (± 0.28%)	12.25s (± 0.43%)	+0.01s (+ 0.09%)	12.17s	12.38s
Monaco - node (v10.16.3, x64)
Memory used	366,213k (± 0.01%)	366,145k (± 0.01%)	-68k (- 0.02%)	366,038k	366,273k
Parse Time	1.25s (± 0.61%)	1.26s (± 0.85%)	+0.01s (+ 0.48%)	1.25s	1.29s
Bind Time	0.76s (± 0.49%)	0.76s (± 0.48%)	+0.00s (+ 0.13%)	0.75s	0.76s
Check Time	4.65s (± 0.59%)	4.66s (± 0.64%)	+0.01s (+ 0.28%)	4.58s	4.72s
Emit Time	2.93s (± 0.71%)	2.94s (± 0.50%)	+0.01s (+ 0.20%)	2.91s	2.98s
Total Time	9.58s (± 0.40%)	9.61s (± 0.48%)	+0.03s (+ 0.28%)	9.51s	9.73s
TFS - node (v10.16.3, x64)
Memory used	321,970k (± 0.03%)	321,977k (± 0.01%)	+7k (+ 0.00%)	321,915k	322,039k
Parse Time	0.95s (± 0.71%)	0.95s (± 0.86%)	-0.00s (- 0.10%)	0.94s	0.97s
Bind Time	0.73s (± 1.12%)	0.72s (± 1.38%)	-0.01s (- 0.96%)	0.70s	0.74s
Check Time	4.11s (± 0.35%)	4.14s (± 0.35%)	+0.03s (+ 0.66%)	4.10s	4.17s
Emit Time	3.04s (± 0.78%)	3.06s (± 0.65%)	+0.01s (+ 0.39%)	3.00s	3.10s
Total Time	8.83s (± 0.34%)	8.87s (± 0.33%)	+0.03s (+ 0.38%)	8.82s	8.95s
Angular - node (v12.1.0, x64)
Memory used	330,399k (± 0.04%)	332,012k (± 0.01%)	+1,612k (+ 0.49%)	331,945k	332,113k
Parse Time	1.57s (± 0.63%)	1.59s (± 0.56%)	+0.02s (+ 1.08%)	1.57s	1.61s
Bind Time	0.84s (± 0.68%)	0.85s (± 0.52%)	+0.01s (+ 1.43%)	0.84s	0.86s
Check Time	4.42s (± 0.44%)	4.47s (± 0.42%)	+0.05s (+ 1.15%)	4.43s	4.51s
Emit Time	5.47s (± 1.35%)	5.52s (± 0.68%)	+0.05s (+ 0.91%)	5.45s	5.62s
Total Time	12.30s (± 0.69%)	12.43s (± 0.32%)	+0.13s (+ 1.06%)	12.34s	12.53s
Monaco - node (v12.1.0, x64)
Memory used	345,927k (± 0.01%)	345,898k (± 0.01%)	-29k (- 0.01%)	345,827k	346,030k
Parse Time	1.23s (± 0.42%)	1.22s (± 0.61%)	-0.01s (- 0.73%)	1.20s	1.23s
Bind Time	0.72s (± 1.15%)	0.72s (± 0.65%)	-0.00s (- 0.69%)	0.71s	0.73s
Check Time	4.49s (± 0.27%)	4.49s (± 0.56%)	-0.01s (- 0.18%)	4.43s	4.54s
Emit Time	2.98s (± 1.31%)	2.98s (± 1.07%)	+0.00s (+ 0.07%)	2.93s	3.09s
Total Time	9.43s (± 0.42%)	9.41s (± 0.50%)	-0.02s (- 0.18%)	9.34s	9.53s
TFS - node (v12.1.0, x64)
Memory used	304,312k (± 0.02%)	304,352k (± 0.02%)	+40k (+ 0.01%)	304,231k	304,476k
Parse Time	0.95s (± 0.71%)	0.95s (± 1.00%)	+0.00s (+ 0.00%)	0.92s	0.96s
Bind Time	0.68s (± 0.69%)	0.68s (± 0.33%)	-0.00s (- 0.15%)	0.67s	0.68s
Check Time	4.05s (± 0.63%)	4.05s (± 0.44%)	+0.01s (+ 0.17%)	4.01s	4.09s
Emit Time	3.05s (± 1.01%)	3.07s (± 0.46%)	+0.02s (+ 0.69%)	3.04s	3.10s
Total Time	8.72s (± 0.50%)	8.75s (± 0.23%)	+0.03s (+ 0.33%)	8.70s	8.80s
Angular - node (v8.9.0, x64)
Memory used	349,620k (± 0.01%)	351,274k (± 0.01%)	+1,654k (+ 0.47%)	351,166k	351,312k
Parse Time	2.10s (± 0.40%)	2.11s (± 0.36%)	+0.01s (+ 0.62%)	2.10s	2.13s
Bind Time	0.91s (± 0.71%)	0.92s (± 0.79%)	+0.01s (+ 1.54%)	0.91s	0.94s
Check Time	5.29s (± 0.61%)	5.28s (± 0.54%)	-0.00s (- 0.08%)	5.23s	5.35s
Emit Time	6.23s (± 1.08%)	6.26s (± 0.71%)	+0.03s (+ 0.55%)	6.15s	6.37s
Total Time	14.52s (± 0.69%)	14.58s (± 0.36%)	+0.06s (+ 0.43%)	14.48s	14.72s
Monaco - node (v8.9.0, x64)
Memory used	364,019k (± 0.01%)	364,016k (± 0.01%)	-3k (- 0.00%)	363,893k	364,129k
Parse Time	1.56s (± 0.48%)	1.56s (± 0.31%)	0.00s ( 0.00%)	1.55s	1.57s
Bind Time	0.93s (± 0.78%)	0.93s (± 0.70%)	0.00s ( 0.00%)	0.91s	0.94s
Check Time	5.57s (± 0.59%)	5.56s (± 0.44%)	-0.01s (- 0.13%)	5.50s	5.60s
Emit Time	3.03s (± 0.62%)	3.04s (± 0.84%)	+0.01s (+ 0.20%)	3.00s	3.11s
Total Time	11.09s (± 0.41%)	11.09s (± 0.37%)	-0.00s (- 0.04%)	11.04s	11.20s
TFS - node (v8.9.0, x64)
Memory used	320,953k (± 0.01%)	320,948k (± 0.02%)	-5k (- 0.00%)	320,823k	321,050k
Parse Time	1.26s (± 0.51%)	1.26s (± 0.29%)	+0.00s (+ 0.16%)	1.26s	1.27s
Bind Time	0.74s (± 0.60%)	0.74s (± 0.75%)	-0.00s (- 0.00%)	0.73s	0.75s
Check Time	4.75s (± 0.40%)	4.73s (± 0.54%)	-0.02s (- 0.34%)	4.69s	4.81s
Emit Time	3.19s (± 0.95%)	3.19s (± 0.45%)	+0.00s (+ 0.03%)	3.17s	3.23s
Total Time	9.94s (± 0.48%)	9.93s (± 0.39%)	-0.02s (- 0.15%)	9.86s	10.02s
Angular - node (v8.9.0, x86)
Memory used	198,592k (± 0.02%)	199,462k (± 0.02%)	+870k (+ 0.44%)	199,388k	199,511k
Parse Time	2.03s (± 0.90%)	2.04s (± 0.39%)	+0.01s (+ 0.64%)	2.02s	2.06s
Bind Time	1.04s (± 1.19%)	1.01s (± 0.59%)	-0.03s (- 2.68%)	1.00s	1.03s
Check Time	4.81s (± 0.38%)	4.80s (± 0.52%)	-0.00s (- 0.04%)	4.77s	4.88s
Emit Time	6.01s (± 0.79%)	6.00s (± 0.46%)	-0.02s (- 0.30%)	5.94s	6.05s
Total Time	13.89s (± 0.46%)	13.86s (± 0.19%)	-0.03s (- 0.24%)	13.81s	13.93s
Monaco - node (v8.9.0, x86)
Memory used	203,931k (± 0.02%)	203,943k (± 0.03%)	+13k (+ 0.01%)	203,827k	204,076k
Parse Time	1.61s (± 0.90%)	1.62s (± 1.12%)	+0.01s (+ 0.37%)	1.59s	1.66s
Bind Time	0.74s (± 0.87%)	0.74s (± 0.80%)	+0.00s (+ 0.27%)	0.73s	0.76s
Check Time	5.40s (± 0.84%)	5.39s (± 1.19%)	-0.02s (- 0.31%)	5.15s	5.48s
Emit Time	2.88s (± 2.58%)	2.89s (± 2.67%)	+0.00s (+ 0.14%)	2.81s	3.18s
Total Time	10.65s (± 0.46%)	10.64s (± 0.49%)	-0.01s (- 0.06%)	10.53s	10.74s
TFS - node (v8.9.0, x86)
Memory used	180,831k (± 0.03%)	180,869k (± 0.02%)	+38k (+ 0.02%)	180,771k	180,947k
Parse Time	1.31s (± 0.85%)	1.30s (± 0.81%)	-0.00s (- 0.23%)	1.28s	1.33s
Bind Time	0.69s (± 0.99%)	0.70s (± 0.68%)	+0.00s (+ 0.29%)	0.69s	0.71s
Check Time	4.50s (± 0.74%)	4.47s (± 0.65%)	-0.03s (- 0.60%)	4.40s	4.55s
Emit Time	2.96s (± 0.71%)	2.97s (± 1.53%)	+0.01s (+ 0.27%)	2.85s	3.09s
Total Time	9.46s (± 0.63%)	9.44s (± 0.78%)	-0.02s (- 0.23%)	9.33s	9.63s

System

Machine Name	ts-ci-ubuntu
Platform	linux 4.4.0-166-generic
Architecture	x64
Available Memory	16 GB
Available Memory	6 GB
CPUs	4 × Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz

Hosts

• node (v10.16.3, x64)
• node (v12.1.0, x64)
• node (v8.9.0, x64)
• node (v8.9.0, x86)

Scenarios

• Angular - node (v10.16.3, x64)
• Angular - node (v12.1.0, x64)
• Angular - node (v8.9.0, x64)
• Angular - node (v8.9.0, x86)
• Monaco - node (v10.16.3, x64)
• Monaco - node (v12.1.0, x64)
• Monaco - node (v8.9.0, x64)
• Monaco - node (v8.9.0, x86)
• TFS - node (v10.16.3, x64)
• TFS - node (v12.1.0, x64)
• TFS - node (v8.9.0, x64)
• TFS - node (v8.9.0, x86)

Benchmark	Name	Iterations
Current	35513	10
Baseline	master	10

[TypeScript Bot (typescript-bot)]

The user suite test run you requested has finished and failed. I've opened a PR with the baseline diff from master.

[Anders Hejlsberg (ahejlsberg)]

RWC and Community test errors look to be preexisting conditions.

[Wesley Wigham (weswigham)]

RWC is clean on master. Maybe try syncing the branch and running again? Otherwise the change is real.

[Anders Hejlsberg (ahejlsberg)]

Looked at it more closely. The RWC difference is just simple error message change because we now pick a different (and arguably better) union constituent to elaborate.

[Wesley Wigham (weswigham)]

What's the justification for not maybe instantiables here? Previously it was "not generic indexes", so this is quite a bit broader an exclusion, if I'm not mistaken.

[Anders Hejlsberg (ahejlsberg)]

If you look at isGenericIndexType you'll see that it's more than just generic index types. The code change just clarifies what's actually going on, there's no change in behavior.

[Wesley Wigham (weswigham)]

Huh, alright, so it's equivalent. Neat.

[Wesley Wigham (weswigham)]

Do we also need to apply/extended similar logic to conditionals in some way? Like if I have a
(T extends U ? { type: "a" } : { type: "b" }) & { type: "b" }, shouldn't it be similarly simplified (at least outside of when infer variables are present)?