{} & null and {} & undefined should always be never by ahejlsberg · Pull Request #50553 · microsoft/TypeScript

ahejlsberg · 2022-08-30T21:53:55Z

…mode

ahejlsberg · 2022-08-30T21:54:50Z

@typescript-bot test this
@typescript-bot user test this inline
@typescript-bot run dt
@typescript-bot perf test faster
@typescript-bot test top100

typescript-bot · 2022-08-30T21:54:53Z

Heya @ahejlsberg, I've started to run the extended test suite on this PR at dd32cf8. You can monitor the build here.

typescript-bot · 2022-08-30T21:54:53Z

Heya @ahejlsberg, I've started to run the diff-based user code test suite on this PR at dd32cf8. You can monitor the build here.

Update: The results are in!

typescript-bot · 2022-08-30T21:54:53Z

Heya @ahejlsberg, I've started to run the parallelized Definitely Typed test suite on this PR at dd32cf8. You can monitor the build here.

typescript-bot · 2022-08-30T21:54:53Z

Heya @ahejlsberg, I've started to run the abridged perf test suite on this PR at dd32cf8. You can monitor the build here.

Update: The results are in!

typescript-bot · 2022-08-30T21:54:53Z

Heya @ahejlsberg, I've started to run the diff-based user code test suite on this PR at dd32cf8. You can monitor the build here.

Update: The results are in!

Gadrawingz · 2022-08-30T21:59:32Z

I'm willing to join

typescript-bot · 2022-08-30T22:08:21Z

@ahejlsberg Here are the results of running the user test suite comparing main and refs/pull/50553/merge:

Everything looks good!

typescript-bot · 2022-08-30T22:08:47Z

@ahejlsberg
The results of the perf run you requested are in!

Here they are:

Comparison Report - main..50553

_Metric	_main	₅₀₅₅₃	_Delta	_Best	_Worst
_{Angular - node (v14.15.1, x64)}
_{Memory used}	_{338,723k (± 0.01%)}	_{338,737k (± 0.00%)}	_{+14k (+ 0.00%)}	_338,698k	_338,759k
_{Parse Time}	_{2.06s (± 0.53%)}	_{2.07s (± 1.04%)}	_{+0.01s (+ 0.49%)}	_2.04s	_2.15s
_{Bind Time}	_{0.79s (± 0.70%)}	_{0.79s (± 0.59%)}	_{-0.00s (- 0.25%)}	_0.78s	_0.80s
_{Check Time}	_{5.82s (± 0.66%)}	_{5.82s (± 0.45%)}	_{-0.00s (- 0.09%)}	_5.77s	_5.90s
_{Emit Time}	_{6.17s (± 1.03%)}	_{6.15s (± 0.93%)}	_{-0.02s (- 0.29%)}	_5.99s	_6.28s
_{Total Time}	_{14.83s (± 0.56%)}	_{14.82s (± 0.52%)}	_{-0.01s (- 0.07%)}	_14.67s	_15.04s
_{Compiler-Unions - node (v14.15.1, x64)}
_{Memory used}	_{192,632k (± 0.01%)}	_{192,963k (± 0.38%)}	_{+331k (+ 0.17%)}	_192,603k	_195,913k
_{Parse Time}	_{0.85s (± 0.70%)}	_{0.85s (± 0.40%)}	_{-0.01s (- 0.94%)}	_0.84s	_0.85s
_{Bind Time}	_{0.48s (± 0.77%)}	_{0.49s (± 0.75%)}	_{+0.00s (+ 0.21%)}	_0.48s	_0.49s
_{Check Time}	_{6.67s (± 0.38%)}	_{6.72s (± 0.65%)}	_{+0.05s (+ 0.70%)}	_6.64s	_6.84s
_{Emit Time}	_{2.41s (± 0.88%)}	_{2.44s (± 1.18%)}	_{+0.04s (+ 1.45%)}	_2.40s	_2.52s
_{Total Time}	_{10.42s (± 0.40%)}	_{10.49s (± 0.53%)}	_{+0.07s (+ 0.71%)}	_10.39s	_10.64s
_{Monaco - node (v14.15.1, x64)}
_{Memory used}	_{326,520k (± 0.01%)}	_{326,529k (± 0.01%)}	_{+9k (+ 0.00%)}	_326,448k	_326,575k
_{Parse Time}	_{1.56s (± 0.33%)}	_{1.57s (± 0.49%)}	_{+0.00s (+ 0.26%)}	_1.55s	_1.59s
_{Bind Time}	_{0.72s (± 0.72%)}	_{0.72s (± 0.80%)}	_{+0.00s (+ 0.28%)}	_0.71s	_0.73s
_{Check Time}	_{5.69s (± 0.47%)}	_{5.75s (± 0.28%)}	_{+0.06s (+ 0.98%)}	_5.72s	_5.79s
_{Emit Time}	_{3.30s (± 0.54%)}	_{3.35s (± 0.81%)}	_{+0.05s (+ 1.51%)}	_3.30s	_3.44s
_{Total Time}	_{11.29s (± 0.34%)}	_{11.40s (± 0.32%)}	_{+0.11s (+ 0.99%)}	_11.30s	_11.49s
_{TFS - node (v14.15.1, x64)}
_{Memory used}	_{289,651k (± 0.00%)}	_{289,637k (± 0.01%)}	_{-15k (- 0.01%)}	_289,576k	_289,672k
_{Parse Time}	_{1.30s (± 0.76%)}	_{1.30s (± 1.08%)}	_{0.00s ( 0.00%)}	_1.28s	_1.35s
_{Bind Time}	_{0.79s (± 0.70%)}	_{0.79s (± 1.60%)}	_{-0.00s (- 0.38%)}	_0.74s	_0.80s
_{Check Time}	_{5.33s (± 0.36%)}	_{5.33s (± 0.30%)}	_{-0.01s (- 0.11%)}	_5.29s	_5.36s
_{Emit Time}	_{3.57s (± 0.58%)}	_{3.58s (± 0.68%)}	_{+0.00s (+ 0.11%)}	_3.54s	_3.65s
_{Total Time}	_{11.00s (± 0.33%)}	_{10.99s (± 0.34%)}	_{-0.01s (- 0.05%)}	_10.93s	_11.09s
_{material-ui - node (v14.15.1, x64)}
_{Memory used}	_{438,119k (± 0.04%)}	_{438,201k (± 0.01%)}	_{+83k (+ 0.02%)}	_438,118k	_438,263k
_{Parse Time}	_{1.85s (± 0.51%)}	_{1.86s (± 0.54%)}	_{+0.01s (+ 0.32%)}	_1.84s	_1.88s
_{Bind Time}	_{0.58s (± 0.51%)}	_{0.58s (± 0.84%)}	_{+0.01s (+ 1.04%)}	_0.57s	_0.59s
_{Check Time}	_{12.83s (± 0.48%)}	_{12.82s (± 0.53%)}	_{-0.01s (- 0.08%)}	_12.70s	_12.97s
_{Emit Time}	_{0.00s (± 0.00%)}	_{0.00s (± 0.00%)}	_{0.00s ( NaN%)}	_0.00s	_0.00s
_{Total Time}	_{15.26s (± 0.41%)}	_{15.26s (± 0.41%)}	_{-0.00s (- 0.01%)}	_15.15s	_15.40s
_{xstate - node (v14.15.1, x64)}
_{Memory used}	_{547,419k (± 0.00%)}	_{547,385k (± 0.00%)}	_{-33k (- 0.01%)}	_547,352k	_547,428k
_{Parse Time}	_{2.59s (± 0.36%)}	_{2.59s (± 0.49%)}	_{+0.00s (+ 0.19%)}	_2.57s	_2.63s
_{Bind Time}	_{0.97s (± 0.89%)}	_{0.97s (± 1.14%)}	_{-0.00s (- 0.10%)}	_0.93s	_0.99s
_{Check Time}	_{1.53s (± 0.54%)}	_{1.54s (± 0.72%)}	_{+0.01s (+ 0.92%)}	_1.52s	_1.57s
_{Emit Time}	_{0.07s (± 0.00%)}	_{0.07s (± 0.00%)}	_{0.00s ( 0.00%)}	_0.07s	_0.07s
_{Total Time}	_{5.16s (± 0.18%)}	_{5.17s (± 0.35%)}	_{+0.01s (+ 0.25%)}	_5.14s	_5.23s

System

_{Machine Name}	_ts-ci-ubuntu
_Platform	_{linux 4.4.0-210-generic}
_Architecture	_x64
_{Available Memory}	_{16 GB}
_{Available Memory}	_{15 GB}
_CPUs	_{4 × Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz}

Hosts

node (v14.15.1, x64)

Scenarios

Angular - node (v14.15.1, x64)
Compiler-Unions - node (v14.15.1, x64)
Monaco - node (v14.15.1, x64)
TFS - node (v14.15.1, x64)
material-ui - node (v14.15.1, x64)
xstate - node (v14.15.1, x64)

_Benchmark	_Name	_Iterations
_Current	₅₀₅₅₃	₁₀
_Baseline	_main	₁₀

Developer Information:

Download Benchmark

typescript-bot · 2022-08-30T22:16:44Z

Heya @ahejlsberg, I've run the RWC suite on this PR - assuming you're on the TS core team, you can view the resulting diff here.

typescript-bot · 2022-08-30T23:49:33Z

@ahejlsberg Here are the results of running the top-repos suite comparing main and refs/pull/50553/merge:

Everything looks good!

ahejlsberg · 2022-08-31T04:52:58Z

Tests are all clean and perf looks good. Ready to merge.

Andarist · 2022-08-31T05:36:31Z

tests/cases/compiler/NonNullableInNonStrictMode.ts

+type NonNullableNew<T> = T & {};
+type NonNullableOld<T> = T extends null | undefined ? never : T;
+
+type IsNullWithoutStrictNullChecks = NonNullableNew<null>;


nit: this name seems to be confusing to me since it doesn't actually describe the expected result (if I understand correctly) but rather it refers to what was a bug

DanielRosenwasser · 2022-08-31T07:39:29Z

tests/cases/compiler/NonNullableInNonStrictMode.ts

@@ -0,0 +1,18 @@
+// @strict: false


I think it would be good to actually test these behaviors in both strict on and off.

Suggested change

// @strict: false

// @strict: true,false

Then rename the test to nonNullablesAndObjectIntersections.ts

DanielRosenwasser · 2022-08-31T07:41:35Z

@typescript-bot perf test faster

typescript-bot · 2022-08-31T07:41:38Z

Heya @DanielRosenwasser, I've started to run the abridged perf test suite on this PR at dd32cf8. You can monitor the build here.

Update: The results are in!

typescript-bot · 2022-08-31T08:07:36Z

@DanielRosenwasser
The results of the perf run you requested are in!

Here they are:

Comparison Report - main..50553

_Metric	_main	₅₀₅₅₃	_Delta	_Best	_Worst
_{Angular - node (v14.15.1, x64)}
_{Memory used}	_{338,732k (± 0.00%)}	_{338,740k (± 0.00%)}	_{+8k (+ 0.00%)}	_338,710k	_338,766k
_{Parse Time}	_{2.08s (± 1.37%)}	_{2.10s (± 0.89%)}	_{+0.02s (+ 0.72%)}	_2.06s	_2.16s
_{Bind Time}	_{0.79s (± 0.38%)}	_{0.80s (± 0.47%)}	_{+0.00s (+ 0.38%)}	_0.79s	_0.80s
_{Check Time}	_{5.82s (± 0.45%)}	_{5.81s (± 0.39%)}	_{-0.01s (- 0.15%)}	_5.77s	_5.86s
_{Emit Time}	_{6.14s (± 0.63%)}	_{6.17s (± 0.86%)}	_{+0.02s (+ 0.39%)}	_6.07s	_6.29s
_{Total Time}	_{14.84s (± 0.46%)}	_{14.87s (± 0.49%)}	_{+0.03s (+ 0.23%)}	_14.70s	_15.04s
_{Compiler-Unions - node (v14.15.1, x64)}
_{Memory used}	_{192,635k (± 0.01%)}	_{192,645k (± 0.01%)}	_{+10k (+ 0.00%)}	_192,614k	_192,688k
_{Parse Time}	_{0.86s (± 0.78%)}	_{0.86s (± 0.72%)}	_{+0.00s (+ 0.47%)}	_0.85s	_0.87s
_{Bind Time}	_{0.49s (± 0.91%)}	_{0.49s (± 0.81%)}	_{+0.00s (+ 0.61%)}	_0.48s	_0.50s
_{Check Time}	_{6.69s (± 0.41%)}	_{6.75s (± 0.37%)}	_{+0.06s (+ 0.91%)}	_6.71s	_6.81s
_{Emit Time}	_{2.39s (± 0.46%)}	_{2.41s (± 1.09%)}	_{+0.02s (+ 0.84%)}	_2.35s	_2.49s
_{Total Time}	_{10.43s (± 0.28%)}	_{10.52s (± 0.44%)}	_{+0.09s (+ 0.86%)}	_10.45s	_10.66s
_{Monaco - node (v14.15.1, x64)}
_{Memory used}	_{326,520k (± 0.01%)}	_{326,517k (± 0.01%)}	_{-3k (- 0.00%)}	_326,476k	_326,579k
_{Parse Time}	_{1.58s (± 0.64%)}	_{1.59s (± 0.51%)}	_{+0.01s (+ 0.76%)}	_1.57s	_1.61s
_{Bind Time}	_{0.72s (± 0.77%)}	_{0.73s (± 0.65%)}	_{+0.01s (+ 0.69%)}	_0.72s	_0.74s
_{Check Time}	_{5.72s (± 0.28%)}	_{5.72s (± 0.50%)}	_{+0.00s (+ 0.07%)}	_5.65s	_5.80s
_{Emit Time}	_{3.32s (± 0.72%)}	_{3.34s (± 0.60%)}	_{+0.02s (+ 0.66%)}	_3.28s	_3.37s
_{Total Time}	_{11.33s (± 0.25%)}	_{11.38s (± 0.35%)}	_{+0.04s (+ 0.36%)}	_11.28s	_11.45s
_{TFS - node (v14.15.1, x64)}
_{Memory used}	_{289,622k (± 0.01%)}	_{289,643k (± 0.00%)}	_{+21k (+ 0.01%)}	_289,620k	_289,669k
_{Parse Time}	_{1.30s (± 0.73%)}	_{1.31s (± 0.95%)}	_{+0.00s (+ 0.23%)}	_1.29s	_1.35s
_{Bind Time}	_{0.79s (± 0.78%)}	_{0.79s (± 0.60%)}	_{+0.00s (+ 0.25%)}	_0.78s	_0.80s
_{Check Time}	_{5.34s (± 0.39%)}	_{5.36s (± 0.43%)}	_{+0.01s (+ 0.26%)}	_5.29s	_5.39s
_{Emit Time}	_{3.60s (± 0.64%)}	_{3.56s (± 1.19%)}	_{-0.03s (- 0.83%)}	_3.50s	_3.66s
_{Total Time}	_{11.03s (± 0.37%)}	_{11.02s (± 0.46%)}	_{-0.01s (- 0.07%)}	_10.91s	_11.14s
_{material-ui - node (v14.15.1, x64)}
_{Memory used}	_{438,198k (± 0.00%)}	_{438,127k (± 0.04%)}	_{-71k (- 0.02%)}	_437,419k	_438,239k
_{Parse Time}	_{1.86s (± 0.40%)}	_{1.87s (± 0.82%)}	_{+0.01s (+ 0.54%)}	_1.84s	_1.91s
_{Bind Time}	_{0.58s (± 0.82%)}	_{0.58s (± 0.69%)}	_{-0.00s (- 0.69%)}	_0.57s	_0.59s
_{Check Time}	_{12.90s (± 0.52%)}	_{12.94s (± 0.91%)}	_{+0.04s (+ 0.29%)}	_12.70s	_13.26s
_{Emit Time}	_{0.00s (± 0.00%)}	_{0.00s (± 0.00%)}	_{0.00s ( NaN%)}	_0.00s	_0.00s
_{Total Time}	_{15.34s (± 0.43%)}	_{15.39s (± 0.81%)}	_{+0.04s (+ 0.29%)}	_15.15s	_15.75s
_{xstate - node (v14.15.1, x64)}
_{Memory used}	_{547,392k (± 0.00%)}	_{547,420k (± 0.00%)}	_{+29k (+ 0.01%)}	_547,365k	_547,456k
_{Parse Time}	_{2.60s (± 0.32%)}	_{2.61s (± 0.54%)}	_{+0.01s (+ 0.50%)}	_2.59s	_2.64s
_{Bind Time}	_{0.97s (± 0.77%)}	_{0.98s (± 0.74%)}	_{+0.01s (+ 0.51%)}	_0.96s	_1.00s
_{Check Time}	_{1.54s (± 0.54%)}	_{1.54s (± 0.84%)}	_{+0.00s (+ 0.26%)}	_1.52s	_1.57s
_{Emit Time}	_{0.07s (± 3.14%)}	_{0.07s (± 0.00%)}	_{-0.00s (- 1.41%)}	_0.07s	_0.07s
_{Total Time}	_{5.19s (± 0.30%)}	_{5.21s (± 0.49%)}	_{+0.02s (+ 0.39%)}	_5.15s	_5.26s

System

_{Machine Name}	_ts-ci-ubuntu
_Platform	_{linux 4.4.0-210-generic}
_Architecture	_x64
_{Available Memory}	_{16 GB}
_{Available Memory}	_{15 GB}
_CPUs	_{4 × Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz}

Hosts

node (v14.15.1, x64)

Scenarios

Angular - node (v14.15.1, x64)
Compiler-Unions - node (v14.15.1, x64)
Monaco - node (v14.15.1, x64)
TFS - node (v14.15.1, x64)
material-ui - node (v14.15.1, x64)
xstate - node (v14.15.1, x64)

_Benchmark	_Name	_Iterations
_Current	₅₀₅₅₃	₁₀
_Baseline	_main	₁₀

Developer Information:

Download Benchmark

weswigham · 2022-08-31T08:47:18Z

src/compiler/checker.ts

@@ -15166,7 +15166,7 @@ namespace ts {
                return includes & TypeFlags.IncludesWildcard ? wildcardType : anyType;
            }
            if (!strictNullChecks && includes & TypeFlags.Nullable) {


Can't we try to delete this whole !strictNullChecks branch entirely? Or are you still fine with undefined & null being weirdly undefined in non-strict but never in strict?

We need that check for cases where the intersection is a singleton null or undefined. undefined & null is already resolved to never by an earlier check.

Oh, yeah, duh, I know why we can just delete this branch - 15 lines up there's a strictNullChecks only branch that does this already for strict mode - we can just delete both that strictNullChecks gate and this entire conditional.

Nah, that branch also resolves null & object and null & { foo: string } to never, which we don't want to do in non-strictNullChecks mode.

But why not? If we're already adjusting null & {}, isn't that just a logical followup? null & {x} seems even more suspect than null & {}.

The whole premise of null and undefined being in the domain of every type is suspect. But that's non-strictNullChecks. My only objective here is to better align with pre-4.8 behavior in a corner case.

I would be open to seeing what happens and considering such a change for 4.9, but I think this workaround for 4.8 is okay for now.

andrewbranch · 2022-09-01T15:35:50Z

@typescript-bot cherry-pick this to release-4.8

typescript-bot · 2022-09-01T15:35:54Z

Heya @andrewbranch, I've started to run the task to cherry-pick this into release-4.8 on this PR at 4502553. You can monitor the build here.

typescript-bot · 2022-09-01T15:41:48Z

Hey @andrewbranch, I've opened #50589 for you.

Component commits: 3652682 {} & null and {} & undefined should be never in non-strictNullChecks mode dd32cf8 Add tests 03cb73f Address code review feedback 4502553 Accept new baselines

andrewbranch · 2022-09-01T18:56:45Z

@ahejlsberg ready to merge?

Component commits: 3652682 {} & null and {} & undefined should be never in non-strictNullChecks mode dd32cf8 Add tests 03cb73f Address code review feedback 4502553 Accept new baselines Co-authored-by: Anders Hejlsberg <andersh@microsoft.com>

ahejlsberg added 2 commits August 30, 2022 14:26

{} & null and {} & undefined should be never in non-strictNullChecks …

3652682

…mode

Add tests

dd32cf8

typescript-bot assigned ahejlsberg Aug 30, 2022

typescript-bot added Author: Team For Milestone Bug PRs that fix a bug with a specific milestone labels Aug 30, 2022

ahejlsberg requested review from DanielRosenwasser and RyanCavanaugh August 30, 2022 21:54

Andarist reviewed Aug 31, 2022

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DanielRosenwasser reviewed Aug 31, 2022

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weswigham reviewed Aug 31, 2022

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ahejlsberg added 2 commits September 1, 2022 07:52

Address code review feedback

03cb73f

Accept new baselines

4502553

andrewbranch approved these changes Sep 1, 2022

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typescript-bot mentioned this pull request Sep 1, 2022

🤖 Pick PR #50553 ({} & null and {} & undefined should...) into release-4.8 #50589

Merged

DanielRosenwasser approved these changes Sep 1, 2022

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ahejlsberg merged commit 6db2c88 into main Sep 1, 2022

ahejlsberg deleted the fix50519 branch September 1, 2022 19:37

sync-by-unito bot mentioned this pull request Sep 13, 2022

build(deps-dev): bump typescript from 4.6.4 to 4.8.3 numbersprotocol/capture-cam#2065

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