Fixed narrowing based on aliased discriminants coming from destructured parameters

[Andarist]

fixes #56351

[weswigham]

@typescript-bot test this
@typescript-bot run dt
@typescript-bot test top100
@typescript-bot perf test this

[typescript-bot]

Heya @weswigham, I've started to run the diff-based top-repos suite on this PR at 7253100. 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 7253100. 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 7253100. You can monitor the build here.

Update: The results are in!

[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	295,488k (± 0.01%)	295,449k (± 0.01%)	~	295,395k	295,502k	p=0.066 n=6
Parse Time	2.65s (± 0.21%)	2.65s (± 0.24%)	~	2.64s	2.66s	p=0.201 n=6
Bind Time	0.82s (± 0.63%)	0.82s (± 0.00%)	~	0.82s	0.82s	p=0.174 n=6
Check Time	8.15s (± 0.29%)	8.16s (± 0.09%)	~	8.15s	8.17s	p=0.510 n=6
Emit Time	7.09s (± 0.35%)	7.11s (± 0.28%)	~	7.09s	7.15s	p=0.254 n=6
Total Time	18.71s (± 0.17%)	18.74s (± 0.09%)	~	18.72s	18.77s	p=0.120 n=6
Compiler-Unions - node (v18.15.0, x64)
Memory used	193,457k (± 1.55%)	192,485k (± 1.24%)	~	191,485k	197,356k	p=0.471 n=6
Parse Time	1.36s (± 1.84%)	1.35s (± 0.81%)	~	1.33s	1.36s	p=0.741 n=6
Bind Time	0.72s (± 0.00%)	0.72s (± 0.00%)	~	0.72s	0.72s	p=1.000 n=6
Check Time	9.26s (± 0.55%)	9.23s (± 0.31%)	~	9.21s	9.28s	p=0.289 n=6
Emit Time	2.62s (± 0.46%)	2.62s (± 0.72%)	~	2.60s	2.64s	p=0.806 n=6
Total Time	13.95s (± 0.50%)	13.92s (± 0.30%)	~	13.86s	13.97s	p=0.471 n=6
Monaco - node (v18.15.0, x64)
Memory used	347,395k (± 0.01%)	347,401k (± 0.01%)	~	347,373k	347,420k	p=0.810 n=6
Parse Time	2.46s (± 0.17%)	2.46s (± 0.48%)	~	2.44s	2.47s	p=0.787 n=6
Bind Time	0.92s (± 0.59%)	0.93s (± 0.56%)	~	0.92s	0.93s	p=0.640 n=6
Check Time	6.89s (± 0.30%)	6.88s (± 0.33%)	~	6.86s	6.91s	p=0.366 n=6
Emit Time	4.04s (± 0.29%)	4.05s (± 0.60%)	~	4.02s	4.09s	p=0.292 n=6
Total Time	14.31s (± 0.09%)	14.31s (± 0.34%)	~	14.27s	14.40s	p=0.465 n=6
TFS - node (v18.15.0, x64)
Memory used	302,726k (± 0.00%)	302,721k (± 0.01%)	~	302,695k	302,749k	p=0.470 n=6
Parse Time	1.99s (± 1.51%)	2.00s (± 0.75%)	~	1.99s	2.03s	p=0.514 n=6
Bind Time	1.00s (± 2.08%)	1.01s (± 1.73%)	~	0.99s	1.04s	p=0.166 n=6
Check Time	6.30s (± 0.31%)	6.31s (± 0.34%)	~	6.27s	6.33s	p=0.512 n=6
Emit Time	3.57s (± 0.60%)	3.57s (± 0.51%)	~	3.55s	3.59s	p=0.869 n=6
Total Time	12.86s (± 0.40%)	12.90s (± 0.09%)	~	12.88s	12.91s	p=0.217 n=6
material-ui - node (v18.15.0, x64)
Memory used	506,827k (± 0.00%)	506,818k (± 0.00%)	~	506,787k	506,849k	p=0.521 n=6
Parse Time	2.58s (± 0.57%)	2.58s (± 0.32%)	~	2.57s	2.59s	p=0.740 n=6
Bind Time	0.99s (± 0.99%)	0.99s (± 1.43%)	~	0.97s	1.01s	p=0.869 n=6
Check Time	16.92s (± 0.47%)	16.96s (± 0.20%)	~	16.90s	16.99s	p=0.173 n=6
Emit Time	0.00s (± 0.00%)	0.00s (± 0.00%)	~	0.00s	0.00s	p=1.000 n=6
Total Time	20.49s (± 0.45%)	20.54s (± 0.15%)	~	20.48s	20.56s	p=0.126 n=6
xstate - node (v18.15.0, x64)
Memory used	512,909k (± 0.01%)	512,862k (± 0.01%)	~	512,813k	512,904k	p=0.149 n=6
Parse Time	3.28s (± 0.26%)	3.28s (± 0.26%)	~	3.27s	3.29s	p=0.796 n=6
Bind Time	1.54s (± 0.27%)	1.54s (± 0.26%)	~	1.54s	1.55s	p=0.218 n=6
Check Time	2.81s (± 0.37%)	2.83s (± 0.27%)	+0.02s (+ 0.59%)	2.82s	2.84s	p=0.018 n=6
Emit Time	0.07s (± 0.00%)	0.07s (± 0.00%)	~	0.07s	0.07s	p=1.000 n=6
Total Time	7.70s (± 0.13%)	7.72s (± 0.18%)	+0.03s (+ 0.32%)	7.70s	7.74s	p=0.014 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	2,340ms (± 0.34%)	2,336ms (± 0.49%)	~	2,323ms	2,355ms	p=0.521 n=6
Req 2 - geterr	5,433ms (± 1.34%)	5,456ms (± 1.36%)	~	5,342ms	5,506ms	p=1.000 n=6
Req 3 - references	325ms (± 1.09%)	328ms (± 1.14%)	~	324ms	334ms	p=0.198 n=6
Req 4 - navto	277ms (± 1.30%)	275ms (± 1.18%)	~	273ms	280ms	p=0.357 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	87ms (± 6.04%)	89ms (± 5.97%)	~	82ms	93ms	p=0.869 n=6
CompilerTSServer - node (v18.15.0, x64)
Req 1 - updateOpen	2,496ms (± 0.48%)	2,481ms (± 0.97%)	~	2,442ms	2,516ms	p=0.298 n=6
Req 2 - geterr	4,107ms (± 1.38%)	4,112ms (± 1.55%)	~	4,080ms	4,242ms	p=0.936 n=6
Req 3 - references	340ms (± 0.97%)	346ms (± 0.68%)	+6ms (+ 1.62%)	341ms	347ms	p=0.014 n=6
Req 4 - navto	284ms (± 0.52%)	284ms (± 0.36%)	~	282ms	285ms	p=0.510 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	87ms (± 5.29%)	89ms (± 1.00%)	~	88ms	90ms	p=0.557 n=6
xstateTSServer - node (v18.15.0, x64)
Req 1 - updateOpen	2,607ms (± 0.33%)	2,599ms (± 0.64%)	~	2,577ms	2,622ms	p=0.521 n=6
Req 2 - geterr	1,734ms (± 2.52%)	1,686ms (± 2.64%)	-48ms (- 2.79%)	1,634ms	1,743ms	p=0.045 n=6
Req 3 - references	117ms (± 9.01%)	113ms (± 9.41%)	~	102ms	123ms	p=0.466 n=6
Req 4 - navto	365ms (± 0.17%)	364ms (± 0.69%)	~	359ms	366ms	p=0.654 n=6
Req 5 - completionInfo count	2,073 (± 0.00%)	2,073 (± 0.00%)	~	2,073	2,073	p=1.000 n=6
Req 5 - completionInfo	308ms (± 3.06%)	307ms (± 1.79%)	~	298ms	313ms	p=0.809 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	153.17ms (± 0.20%)	153.12ms (± 0.22%)	~	152.04ms	158.29ms	p=0.071 n=600
tsserver-startup - node (v18.15.0, x64)
Execution time	228.45ms (± 0.14%)	228.11ms (± 0.14%)	-0.33ms (- 0.15%)	226.95ms	231.54ms	p=0.000 n=600
tsserverlibrary-startup - node (v18.15.0, x64)
Execution time	230.23ms (± 0.19%)	230.14ms (± 0.18%)	-0.10ms (- 0.04%)	228.47ms	236.68ms	p=0.023 n=600
typescript-startup - node (v18.15.0, x64)
Execution time	229.96ms (± 0.18%)	229.86ms (± 0.21%)	-0.10ms (- 0.04%)	228.10ms	238.01ms	p=0.005 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

[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]

@weswigham Here are the results of running the top-repos suite comparing main and refs/pull/56860/merge:

Everything looks good!