Array subtypes inherit special array variance

[weswigham]

No description provided.

[weswigham]

@typescript-bot pack this
@typescript-bot user test this
@typescript-bot test this
@typescript-bot run dt
@typescript-bot perf test this

[typescript-bot]

Heya @weswigham, I've started to run the diff-based user code test suite on this PR at 3707623. You can monitor the build here.

Update: The results are in!

[typescript-bot]

Heya @weswigham, I've started to run the parallelized Definitely Typed test suite on this PR at 3707623. You can monitor the build here.

Update: The results are in!

[typescript-bot]

Heya @weswigham, I've started to run the regular perf test suite on this PR at 3707623. You can monitor the build here.

Update: The results are in!

[typescript-bot]

Heya @weswigham, I've started to run the tarball bundle task on this PR at 3707623. You can monitor the build here.

[typescript-bot]

Hey @weswigham, I've packed this into an installable tgz. You can install it for testing by referencing it in your package.json like so:

{
    "devDependencies": {
        "typescript": "https://typescript.visualstudio.com/cf7ac146-d525-443c-b23c-0d58337efebc/_apis/build/builds/157949/artifacts?artifactName=tgz&fileId=1C525A6A066DC0D78947723C8F8893323D202C3397E26B624DA138468A3AB06702&fileName=/typescript-5.3.0-insiders.20230926.tgz"
    }
}

and then running npm install.

---

There is also a playground for this build and an npm module you can use via "typescript": "npm:@typescript-deploys/pr-build@5.3.0-pr-55880-5".;

[fatcerberus]

Wait, Array is special-cased to be covariant? That kind of shoots down the argument that method parameters are bivariant just “to ensure arrays continue to relate covariantly”…

[typescript-bot]

@weswigham Here are the results of running the user test suite comparing main and refs/pull/55880/merge:

There were infrastructure failures potentially unrelated to your change:

• 1 instance of "Unknown failure"
• 2 instances of "Package install failed"

Otherwise...

Something interesting changed - please have a look.

Details

webpack

tsconfig.types.json

• [NEW] error TS2322: Type 'undefined' is not assignable to type 'Pick<ArgumentConfig, "values" | "type">'.
  • lib/cli.js#L167
• [MISSING] error TS2322: Type 'undefined' is not assignable to type 'Pick<ArgumentConfig, "type" | "values">'.
  • lib/cli.js#L167

[typescript-bot]

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

Here they are:

Compiler

Comparison Report - baseline..pr

Metric	baseline	pr	Delta	Best	Worst	p-value
Angular - node (v18.15.0, x64)
Memory used	294,969k (± 0.01%)	295,272k (± 0.01%)	+303k (+ 0.10%)	295,250k	295,305k	p=0.005 n=6
Parse Time	2.62s (± 0.34%)	2.63s (± 0.75%)	~	2.60s	2.66s	p=0.801 n=6
Bind Time	0.83s (± 1.00%)	0.84s (± 1.17%)	~	0.83s	0.85s	p=0.588 n=6
Check Time	8.05s (± 0.27%)	8.05s (± 0.41%)	~	8.01s	8.11s	p=0.936 n=6
Emit Time	7.05s (± 0.28%)	7.04s (± 0.33%)	~	7.00s	7.06s	p=0.935 n=6
Total Time	18.55s (± 0.17%)	18.56s (± 0.40%)	~	18.44s	18.67s	p=0.518 n=6
Compiler-Unions - node (v18.15.0, x64)
Memory used	193,488k (± 1.33%)	190,719k (± 0.03%)	~	190,612k	190,763k	p=0.109 n=6
Parse Time	1.34s (± 1.30%)	1.35s (± 1.52%)	~	1.33s	1.38s	p=0.416 n=6
Bind Time	0.73s (± 0.00%)	0.73s (± 0.56%)	~	0.72s	0.73s	p=0.405 n=6
Check Time	9.09s (± 0.32%)	9.14s (± 0.39%)	+0.05s (+ 0.59%)	9.10s	9.20s	p=0.023 n=6
Emit Time	2.63s (± 0.65%)	2.65s (± 0.70%)	~	2.63s	2.67s	p=0.168 n=6
Total Time	13.79s (± 0.29%)	13.87s (± 0.47%)	+0.08s (+ 0.56%)	13.78s	13.97s	p=0.036 n=6
Monaco - node (v18.15.0, x64)
Memory used	347,212k (± 0.00%)	347,219k (± 0.01%)	~	347,192k	347,294k	p=0.689 n=6
Parse Time	2.45s (± 0.40%)	2.46s (± 0.31%)	~	2.45s	2.47s	p=0.300 n=6
Bind Time	0.94s (± 0.00%)	0.94s (± 0.00%)	~	0.94s	0.94s	p=1.000 n=6
Check Time	6.88s (± 0.54%)	6.85s (± 0.54%)	~	6.82s	6.92s	p=0.257 n=6
Emit Time	4.01s (± 0.10%)	4.03s (± 0.36%)	+0.02s (+ 0.50%)	4.01s	4.05s	p=0.021 n=6
Total Time	14.28s (± 0.29%)	14.29s (± 0.35%)	~	14.24s	14.36s	p=1.000 n=6
TFS - node (v18.15.0, x64)
Memory used	302,486k (± 0.01%)	302,489k (± 0.00%)	~	302,477k	302,510k	p=0.936 n=6
Parse Time	1.99s (± 1.62%)	2.00s (± 1.03%)	~	1.98s	2.03s	p=0.280 n=6
Bind Time	1.00s (± 1.21%)	1.01s (± 1.20%)	~	0.99s	1.02s	p=0.680 n=6
Check Time	6.23s (± 0.44%)	6.25s (± 0.36%)	~	6.23s	6.28s	p=0.372 n=6
Emit Time	3.53s (± 0.28%)	3.52s (± 0.29%)	-0.01s (- 0.42%)	3.50s	3.53s	p=0.028 n=6
Total Time	12.75s (± 0.20%)	12.77s (± 0.15%)	~	12.75s	12.80s	p=0.126 n=6
material-ui - node (v18.15.0, x64)
Memory used	470,449k (± 0.00%)	470,686k (± 0.00%)	+236k (+ 0.05%)	470,652k	470,716k	p=0.005 n=6
Parse Time	2.56s (± 0.57%)	2.57s (± 0.70%)	~	2.55s	2.60s	p=0.289 n=6
Bind Time	0.99s (± 0.82%)	0.99s (± 1.34%)	~	0.97s	1.01s	p=0.866 n=6
Check Time	16.52s (± 0.42%)	16.55s (± 0.40%)	~	16.47s	16.66s	p=0.688 n=6
Emit Time	0.00s (± 0.00%)	0.00s (± 0.00%)	~	0.00s	0.00s	p=1.000 n=6
Total Time	20.08s (± 0.38%)	20.11s (± 0.37%)	~	20.00s	20.21s	p=0.573 n=6
xstate - node (v18.15.0, x64)
Memory used	512,553k (± 0.01%)	512,586k (± 0.02%)	~	512,490k	512,715k	p=0.810 n=6
Parse Time	3.27s (± 0.16%)	3.26s (± 0.16%)	-0.01s (- 0.31%)	3.26s	3.27s	p=0.018 n=6
Bind Time	1.56s (± 0.35%)	1.55s (± 0.49%)	~	1.54s	1.56s	p=0.137 n=6
Check Time	2.83s (± 0.55%)	2.83s (± 0.37%)	~	2.82s	2.85s	p=0.514 n=6
Emit Time	0.08s (± 0.00%)	0.08s (± 9.60%)	~	0.07s	0.09s	p=0.598 n=6
Total Time	7.73s (± 0.22%)	7.73s (± 0.13%)	~	7.72s	7.75s	p=0.626 n=6

System info unknown

Hosts

• node (v18.15.0, x64)

Scenarios

• Angular - node (v18.15.0, x64)
• Compiler-Unions - node (v18.15.0, x64)
• Monaco - node (v18.15.0, x64)
• TFS - node (v18.15.0, x64)
• material-ui - node (v18.15.0, x64)
• xstate - node (v18.15.0, x64)

Benchmark	Name	Iterations
Current	pr	6
Baseline	baseline	6

tsserver

Comparison Report - baseline..pr

Metric	baseline	pr	Delta	Best	Worst	p-value
Compiler-UnionsTSServer - node (v18.15.0, x64)
Req 1 - updateOpen	2,355ms (± 0.78%)	2,368ms (± 0.80%)	~	2,341ms	2,388ms	p=0.261 n=6
Req 2 - geterr	5,345ms (± 1.68%)	5,308ms (± 1.60%)	~	5,230ms	5,421ms	p=0.378 n=6
Req 3 - references	329ms (± 1.56%)	328ms (± 2.11%)	~	324ms	342ms	p=0.231 n=6
Req 4 - navto	277ms (± 0.91%)	278ms (± 1.15%)	~	274ms	281ms	p=0.567 n=6
Req 5 - completionInfo count	1,356 (± 0.00%)	1,356 (± 0.00%)	~	1,356	1,356	p=1.000 n=6
Req 5 - completionInfo	82ms (± 8.51%)	82ms (± 7.74%)	~	75ms	90ms	p=0.746 n=6
CompilerTSServer - node (v18.15.0, x64)
Req 1 - updateOpen	2,467ms (± 0.59%)	2,465ms (± 1.09%)	~	2,414ms	2,484ms	p=1.000 n=6
Req 2 - geterr	4,094ms (± 1.45%)	4,118ms (± 1.67%)	~	4,058ms	4,209ms	p=0.689 n=6
Req 3 - references	338ms (± 1.83%)	339ms (± 1.46%)	~	334ms	344ms	p=0.685 n=6
Req 4 - navto	284ms (± 0.36%)	283ms (± 0.35%)	~	282ms	284ms	p=0.437 n=6
Req 5 - completionInfo count	1,518 (± 0.00%)	1,518 (± 0.00%)	~	1,518	1,518	p=1.000 n=6
Req 5 - completionInfo	81ms (± 8.88%)	81ms (± 7.92%)	~	74ms	87ms	p=1.000 n=6
xstateTSServer - node (v18.15.0, x64)
Req 1 - updateOpen	2,598ms (± 0.52%)	2,591ms (± 0.54%)	~	2,573ms	2,605ms	p=0.230 n=6
Req 2 - geterr	1,674ms (± 1.38%)	1,691ms (± 2.29%)	~	1,650ms	1,740ms	p=0.471 n=6
Req 3 - references	107ms (± 0.98%)	123ms (± 7.19%)	~	105ms	128ms	p=0.053 n=6
Req 4 - navto	359ms (± 0.21%)	359ms (± 0.27%)	~	357ms	360ms	p=0.858 n=6
Req 5 - completionInfo count	2,071 (± 0.00%)	2,071 (± 0.00%)	~	2,071	2,071	p=1.000 n=6
Req 5 - completionInfo	305ms (± 2.00%)	309ms (± 2.83%)	~	299ms	318ms	p=0.378 n=6

System info unknown

Hosts

• node (v18.15.0, x64)

Scenarios

• CompilerTSServer - node (v18.15.0, x64)
• Compiler-UnionsTSServer - node (v18.15.0, x64)
• xstateTSServer - node (v18.15.0, x64)

Benchmark	Name	Iterations
Current	pr	6
Baseline	baseline	6

Startup

Comparison Report - baseline..pr

Metric	baseline	pr	Delta	Best	Worst	p-value
tsc-startup - node (v18.15.0, x64)
Execution time	151.70ms (± 0.16%)	151.72ms (± 0.15%)	~	150.72ms	155.30ms	p=0.284 n=600
tsserver-startup - node (v18.15.0, x64)
Execution time	227.66ms (± 0.16%)	227.58ms (± 0.17%)	-0.08ms (- 0.03%)	226.14ms	234.58ms	p=0.017 n=600
tsserverlibrary-startup - node (v18.15.0, x64)
Execution time	228.94ms (± 0.17%)	228.96ms (± 0.16%)	~	227.15ms	233.83ms	p=0.367 n=600
typescript-startup - node (v18.15.0, x64)
Execution time	228.63ms (± 0.15%)	228.50ms (± 0.17%)	-0.13ms (- 0.06%)	227.03ms	235.34ms	p=0.000 n=600

System info unknown

Hosts

• node (v18.15.0, x64)

Scenarios

• tsc-startup - node (v18.15.0, x64)
• tsserver-startup - node (v18.15.0, x64)
• tsserverlibrary-startup - node (v18.15.0, x64)
• typescript-startup - node (v18.15.0, x64)

Benchmark	Name	Iterations
Current	pr	6
Baseline	baseline	6

Developer Information:

Download Benchmarks

[RyanCavanaugh]

That kind of shoots down the argument that method parameters are bivariant just “to ensure arrays continue to relate covariantly”

No, it's still exactly that -- without method bivariance, you can't make arrayish things that are covariant, which means types like Omit<Array<T>, "sort"> would be measured as invariant

interface Arrayish1<out T> {
    indexOf(arg: T): number;
    [n: number]: T;
}

interface Arrayish2<out T> { // <-- error
    indexOf: (arg: T) => number;
    [n: number]: T;
}

[DanielRosenwasser]

@typescript-bot test top300

[typescript-bot]

Heya @DanielRosenwasser, I've started to run the diff-based top-repos suite on this PR at 3707623. You can monitor the build here.

Update: The results are in!

[typescript-bot]

Hey @weswigham, the results of running the DT tests are ready.
Everything looks the same!
You can check the log here.

[typescript-bot]

@DanielRosenwasser Here are the results of running the top-repos suite comparing main and refs/pull/55880/merge:

Everything looks good!