Ensure that Comparers only return -1, 0, 1 so results can be equated

[Jake Bailey (jakebailey)]

I noticed this while working on cleaning up our (inconsistent) use of the binary search and ordered insert APIs.

The binary search API requires that you have comparisons of exactly-1 | 0 | 1, however, we had some comparers which didn't do this thanks to a hole in our type system (Playground Link).

Make it so that we consistently return only one of the three valid values, so comparers can always be used in all APIs.

I also noticed (but did not change) the fact that we use binary searches for things like import insertion with the assumption that the input is always sorted, but, I don't think this actually turns out to be the case all the time anymore?

[Jake Bailey (jakebailey)]

TypeScript Bot (@typescript-bot) perf test this

[TypeScript Bot (typescript-bot)]

Heya Jake Bailey (@jakebailey), I've started to run the perf test suite on this PR at 2106d54. You can monitor the build here.

Update: The results are in!

[Daniel Rosenwasser (DanielRosenwasser)]

Does this catch any actual bugs? Should we just change the comparer type to return number, and use Comparison as a set of easily accessible constants?

[Jake Bailey (jakebailey)]

Does this catch any actual bugs? Should we just change the comparer type to return number, and use Comparison as a set of easily accessible constants?

No, it doesn't, and that surprised me.

If we want to do that, the binary search API needs to change to not check equality on Comparison values. That could definitely be a good fix for this too.

[Jake Bailey (jakebailey)]

Well, it did catch one bug; When I was working on #52891, I accidentally passed getTypeId as a Comparer, and had no idea what I had done wrong. I think that's the benefit here, but, I'm not strongly attached to it.

I think that if we had any existing bugs related to this, they'd already have been caught, because the result is pretty catastrophic.

[TypeScript Bot (typescript-bot)]

Jake Bailey (@jakebailey)
The results of the perf run you requested are in!

Here they are:

Compiler

Comparison Report - main..52897

Metric	main	52897	Delta	Best	Worst	p-value
Angular - node (v18.10.0, x64)
Memory used	359,665k (± 0.01%)	359,683k (± 0.02%)	~	359,592k	359,766k	p=0.689 n=6
Parse Time	3.49s (± 0.88%)	3.48s (± 0.65%)	~	3.45s	3.51s	p=0.519 n=6
Bind Time	1.17s (± 0.64%)	1.17s (± 1.03%)	~	1.15s	1.18s	p=0.485 n=6
Check Time	8.76s (± 0.26%)	8.76s (± 0.34%)	~	8.72s	8.81s	p=0.732 n=6
Emit Time	7.61s (± 1.18%)	7.61s (± 0.63%)	~	7.54s	7.68s	p=0.686 n=6
Total Time	21.02s (± 0.48%)	21.02s (± 0.23%)	~	20.96s	21.10s	p=0.684 n=6
Compiler-Unions - node (v18.10.0, x64)
Memory used	193,630k (± 1.48%)	191,839k (± 1.55%)	~	189,848k	195,726k	p=1.000 n=6
Parse Time	1.48s (± 0.66%)	1.48s (± 0.28%)	~	1.47s	1.48s	p=0.930 n=6
Bind Time	0.80s (± 0.69%)	0.80s (± 0.69%)	~	0.79s	0.80s	p=1.000 n=6
Check Time	9.45s (± 0.58%)	9.46s (± 0.52%)	~	9.41s	9.53s	p=0.686 n=6
Emit Time	2.81s (± 1.13%)	2.81s (± 0.66%)	~	2.79s	2.84s	p=0.570 n=6
Total Time	14.53s (± 0.48%)	14.54s (± 0.31%)	~	14.48s	14.60s	p=0.936 n=6
Monaco - node (v18.10.0, x64)
Memory used	344,051k (± 0.02%)	344,045k (± 0.02%)	~	343,980k	344,129k	p=0.810 n=6
Parse Time	2.62s (± 1.05%)	2.63s (± 1.05%)	~	2.59s	2.66s	p=0.418 n=6
Bind Time	1.05s (± 0.80%)	1.04s (± 0.95%)	~	1.02s	1.05s	p=0.340 n=6
Check Time	7.11s (± 0.25%)	7.13s (± 0.46%)	~	7.08s	7.17s	p=0.195 n=6
Emit Time	4.34s (± 1.06%)	4.33s (± 0.55%)	~	4.29s	4.36s	p=0.739 n=6
Total Time	15.12s (± 0.48%)	15.13s (± 0.15%)	~	15.11s	15.17s	p=0.872 n=6
TFS - node (v18.10.0, x64)
Memory used	300,066k (± 0.00%)	300,089k (± 0.01%)	~	300,062k	300,145k	p=0.054 n=6
Parse Time	2.08s (± 0.77%)	2.04s (± 1.47%)	~	2.01s	2.08s	p=0.163 n=6
Bind Time	1.17s (± 0.76%)	1.18s (± 1.03%)	~	1.17s	1.20s	p=0.437 n=6
Check Time	6.57s (± 0.22%)	6.58s (± 0.28%)	~	6.55s	6.60s	p=0.808 n=6
Emit Time	3.92s (± 0.90%)	3.90s (± 0.42%)	~	3.88s	3.92s	p=0.806 n=6
Total Time	13.74s (± 0.38%)	13.70s (± 0.33%)	~	13.62s	13.75s	p=0.469 n=6
material-ui - node (v18.10.0, x64)
Memory used	476,437k (± 0.01%)	476,400k (± 0.01%)	~	476,373k	476,453k	p=0.066 n=6
Parse Time	3.15s (± 0.52%)	3.16s (± 0.24%)	~	3.15s	3.17s	p=0.216 n=6
Bind Time	0.97s (± 1.01%)	0.97s (± 0.78%)	~	0.96s	0.98s	p=0.652 n=6
Check Time	17.30s (± 0.62%)	17.23s (± 0.74%)	~	17.04s	17.40s	p=0.375 n=6
Emit Time	0.00s (± 0.00%)	0.00s (± 0.00%)	~	0.00s	0.00s	p=1.000 n=6
Total Time	21.42s (± 0.57%)	21.36s (± 0.61%)	~	21.15s	21.53s	p=0.575 n=6
xstate - node (v18.10.0, x64)
Memory used	548,584k (± 0.02%)	548,509k (± 0.03%)	~	548,328k	548,809k	p=0.298 n=6
Parse Time	4.06s (± 0.55%)	4.07s (± 0.40%)	~	4.04s	4.09s	p=0.332 n=6
Bind Time	1.71s (± 0.61%)	1.72s (± 1.35%)	~	1.69s	1.75s	p=1.000 n=6
Check Time	2.83s (± 0.99%)	2.82s (± 0.69%)	~	2.79s	2.84s	p=0.687 n=6
Emit Time	0.08s (± 0.00%)	0.08s (± 6.19%)	~	0.08s	0.09s	p=0.176 n=6
Total Time	8.69s (± 0.40%)	8.69s (± 0.21%)	~	8.66s	8.71s	p=0.935 n=6
Angular - node (v16.17.1, x64)
Memory used	359,020k (± 0.01%)	359,064k (± 0.01%)	~	359,010k	359,124k	p=0.298 n=6
Parse Time	3.72s (± 0.43%)	3.72s (± 0.49%)	~	3.69s	3.73s	p=0.870 n=6
Bind Time	1.23s (± 0.73%)	1.23s (± 0.95%)	~	1.22s	1.25s	p=0.933 n=6
Check Time	9.55s (± 0.31%)	9.52s (± 0.27%)	~	9.48s	9.55s	p=0.107 n=6
Emit Time	8.08s (± 0.44%)	8.05s (± 0.53%)	~	8.00s	8.09s	p=0.373 n=6
Total Time	22.58s (± 0.27%)	22.52s (± 0.18%)	~	22.46s	22.57s	p=0.127 n=6
Compiler-Unions - node (v16.17.1, x64)
Memory used	191,538k (± 0.03%)	191,560k (± 0.04%)	~	191,425k	191,657k	p=0.471 n=6
Parse Time	1.54s (± 1.46%)	1.57s (± 0.52%)	~	1.55s	1.57s	p=0.055 n=6
Bind Time	0.84s (± 0.61%)	0.84s (± 0.00%)	~	0.84s	0.84s	p=0.174 n=6
Check Time	10.11s (± 0.47%)	10.17s (± 0.27%)	~	10.13s	10.20s	p=0.064 n=6
Emit Time	3.05s (± 1.01%)	3.06s (± 0.81%)	~	3.04s	3.11s	p=0.627 n=6
Total Time	15.54s (± 0.41%)	15.63s (± 0.31%)	+0.09s (+ 0.59%)	15.57s	15.71s	p=0.030 n=6
Monaco - node (v16.17.1, x64)
Memory used	343,349k (± 0.00%)	343,344k (± 0.00%)	~	343,320k	343,361k	p=0.375 n=6
Parse Time	2.80s (± 0.71%)	2.80s (± 0.53%)	~	2.78s	2.82s	p=1.000 n=6
Bind Time	1.11s (± 0.37%)	1.11s (± 0.37%)	~	1.11s	1.12s	p=1.000 n=6
Check Time	7.82s (± 0.36%)	7.80s (± 0.20%)	~	7.79s	7.83s	p=0.145 n=6
Emit Time	4.52s (± 0.73%)	4.52s (± 0.83%)	~	4.48s	4.57s	p=0.809 n=6
Total Time	16.25s (± 0.19%)	16.23s (± 0.21%)	~	16.19s	16.28s	p=0.260 n=6
TFS - node (v16.17.1, x64)
Memory used	299,418k (± 0.00%)	299,414k (± 0.01%)	~	299,396k	299,438k	p=0.689 n=6
Parse Time	2.20s (± 0.99%)	2.19s (± 0.55%)	~	2.18s	2.21s	p=0.684 n=6
Bind Time	1.25s (± 0.67%)	1.26s (± 0.41%)	~	1.26s	1.27s	p=0.073 n=6
Check Time	7.25s (± 0.33%)	7.25s (± 0.32%)	~	7.23s	7.28s	p=0.871 n=6
Emit Time	4.24s (± 0.94%)	4.23s (± 0.78%)	~	4.20s	4.29s	p=0.870 n=6
Total Time	14.94s (± 0.51%)	14.94s (± 0.28%)	~	14.89s	14.99s	p=0.936 n=6
material-ui - node (v16.17.1, x64)
Memory used	475,699k (± 0.00%)	475,693k (± 0.00%)	~	475,652k	475,713k	p=0.748 n=6
Parse Time	3.33s (± 0.29%)	3.33s (± 0.25%)	~	3.32s	3.34s	p=0.195 n=6
Bind Time	1.02s (± 0.50%)	1.02s (± 0.00%)	~	1.02s	1.02s	p=0.174 n=6
Check Time	18.28s (± 0.69%)	18.20s (± 0.46%)	~	18.12s	18.35s	p=0.335 n=6
Emit Time	0.00s (± 0.00%)	0.00s (± 0.00%)	~	0.00s	0.00s	p=1.000 n=6
Total Time	22.63s (± 0.57%)	22.55s (± 0.38%)	~	22.46s	22.70s	p=0.261 n=6
xstate - node (v16.17.1, x64)
Memory used	546,132k (± 0.02%)	546,130k (± 0.02%)	~	546,018k	546,277k	p=0.936 n=6
Parse Time	4.25s (± 0.27%)	4.25s (± 0.39%)	~	4.23s	4.28s	p=0.681 n=6
Bind Time	1.81s (± 0.64%)	1.81s (± 0.64%)	~	1.80s	1.83s	p=1.000 n=6
Check Time	3.06s (± 0.96%)	3.07s (± 0.87%)	~	3.02s	3.09s	p=0.802 n=6
Emit Time	0.09s (± 0.00%)	0.09s (± 0.00%)	~	0.09s	0.09s	p=1.000 n=6
Total Time	9.22s (± 0.42%)	9.22s (± 0.37%)	~	9.17s	9.26s	p=1.000 n=6
Angular - node (v14.15.1, x64)
Memory used	352,589k (± 0.01%)	352,586k (± 0.01%)	~	352,562k	352,637k	p=0.810 n=6
Parse Time	3.73s (± 0.26%)	3.71s (± 0.33%)	-0.02s (- 0.45%)	3.70s	3.73s	p=0.027 n=6
Bind Time	1.28s (± 0.70%)	1.28s (± 0.59%)	~	1.27s	1.29s	p=0.798 n=6
Check Time	9.84s (± 0.37%)	9.84s (± 0.60%)	~	9.78s	9.95s	p=0.810 n=6
Emit Time	8.42s (± 0.77%)	8.35s (± 0.39%)	~	8.30s	8.39s	p=0.252 n=6
Total Time	23.28s (± 0.17%)	23.19s (± 0.35%)	~	23.11s	23.33s	p=0.109 n=6
Compiler-Unions - node (v14.15.1, x64)
Memory used	186,673k (± 0.01%)	186,684k (± 0.02%)	~	186,638k	186,727k	p=0.521 n=6
Parse Time	1.58s (± 0.77%)	1.58s (± 1.13%)	~	1.56s	1.61s	p=0.864 n=6
Bind Time	0.86s (± 0.88%)	0.86s (± 0.95%)	~	0.85s	0.87s	p=0.729 n=6
Check Time	10.24s (± 0.76%)	10.24s (± 0.74%)	~	10.16s	10.33s	p=0.809 n=6
Emit Time	3.18s (± 0.70%)	3.17s (± 1.03%)	~	3.13s	3.22s	p=0.327 n=6
Total Time	15.85s (± 0.57%)	15.84s (± 0.49%)	~	15.76s	15.96s	p=0.687 n=6
Monaco - node (v14.15.1, x64)
Memory used	338,190k (± 0.01%)	338,189k (± 0.01%)	~	338,162k	338,212k	p=0.748 n=6
Parse Time	2.90s (± 0.31%)	2.90s (± 0.48%)	~	2.88s	2.91s	p=0.562 n=6
Bind Time	1.12s (± 0.92%)	1.12s (± 0.75%)	~	1.10s	1.12s	p=0.788 n=6
Check Time	8.15s (± 0.27%)	8.13s (± 0.49%)	~	8.08s	8.18s	p=0.295 n=6
Emit Time	4.81s (± 0.46%)	4.77s (± 0.45%)	-0.04s (- 0.83%)	4.74s	4.79s	p=0.016 n=6
Total Time	16.98s (± 0.20%)	16.91s (± 0.32%)	-0.07s (- 0.42%)	16.85s	16.99s	p=0.037 n=6
TFS - node (v14.15.1, x64)
Memory used	294,346k (± 0.00%)	294,351k (± 0.00%)	~	294,341k	294,375k	p=0.748 n=6
Parse Time	2.39s (± 0.62%)	2.38s (± 0.82%)	~	2.37s	2.42s	p=0.459 n=6
Bind Time	1.10s (± 0.99%)	1.10s (± 0.89%)	~	1.09s	1.11s	p=0.859 n=6
Check Time	7.53s (± 0.59%)	7.54s (± 0.43%)	~	7.49s	7.59s	p=0.628 n=6
Emit Time	4.65s (± 0.77%)	4.62s (± 1.17%)	~	4.59s	4.73s	p=0.145 n=6
Total Time	15.66s (± 0.31%)	15.64s (± 0.20%)	~	15.61s	15.70s	p=0.469 n=6
material-ui - node (v14.15.1, x64)
Memory used	471,240k (± 0.00%)	471,233k (± 0.01%)	~	471,198k	471,282k	p=0.377 n=6
Parse Time	3.49s (± 0.12%)	3.49s (± 0.23%)	~	3.48s	3.50s	p=0.584 n=6
Bind Time	1.04s (± 0.61%)	1.04s (± 1.05%)	~	1.03s	1.06s	p=0.787 n=6
Check Time	19.18s (± 0.57%)	19.11s (± 0.43%)	~	19.03s	19.25s	p=0.261 n=6
Emit Time	0.00s (± 0.00%)	0.00s (± 0.00%)	~	0.00s	0.00s	p=1.000 n=6
Total Time	23.72s (± 0.45%)	23.65s (± 0.37%)	~	23.55s	23.79s	p=0.298 n=6
xstate - node (v14.15.1, x64)
Memory used	534,515k (± 0.01%)	534,473k (± 0.02%)	~	534,324k	534,547k	p=0.689 n=6
Parse Time	4.60s (± 0.45%)	4.59s (± 0.22%)	~	4.58s	4.61s	p=0.323 n=6
Bind Time	1.73s (± 0.48%)	1.72s (± 0.30%)	~	1.71s	1.72s	p=0.073 n=6
Check Time	3.16s (± 0.73%)	3.15s (± 0.68%)	~	3.12s	3.18s	p=0.520 n=6
Emit Time	0.10s (± 4.01%)	0.10s (± 0.00%)	~	0.10s	0.10s	p=0.405 n=6
Total Time	9.60s (± 0.22%)	9.57s (± 0.21%)	~	9.55s	9.60s	p=0.064 n=6

System

Machine Name	ts-ci-ubuntu
Platform	linux 5.4.0-135-generic
Architecture	x64
Available Memory	16 GB
Available Memory	15 GB
CPUs	4 × Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz

Hosts

• node (v18.10.0, x64)
• node (v16.17.1, x64)
• node (v14.15.1, x64)

Scenarios

• Angular - node (v18.10.0, x64)
• Angular - node (v16.17.1, x64)
• Angular - node (v14.15.1, x64)
• Compiler-Unions - node (v18.10.0, x64)
• Compiler-Unions - node (v16.17.1, x64)
• Compiler-Unions - node (v14.15.1, x64)
• Monaco - node (v18.10.0, x64)
• Monaco - node (v16.17.1, x64)
• Monaco - node (v14.15.1, x64)
• TFS - node (v18.10.0, x64)
• TFS - node (v16.17.1, x64)
• TFS - node (v14.15.1, x64)
• material-ui - node (v18.10.0, x64)
• material-ui - node (v16.17.1, x64)
• material-ui - node (v14.15.1, x64)
• xstate - node (v18.10.0, x64)
• xstate - node (v16.17.1, x64)
• xstate - node (v14.15.1, x64)

Benchmark	Name	Iterations
Current	52897	6
Baseline	main	6

TSServer

Comparison Report - main..52897

Metric	main	52897	Delta	Best	Worst	p-value
Compiler-UnionsTSServer - node (v18.10.0, x64)
Req 1 - updateOpen	2,380ms (± 0.38%)	2,379ms (± 0.44%)	~	2,367ms	2,394ms	p=0.873 n=6
Req 2 - geterr	5,350ms (± 0.42%)	5,383ms (± 0.31%)	+33ms (+ 0.62%)	5,367ms	5,406ms	p=0.020 n=6
Req 3 - references	342ms (± 1.42%)	341ms (± 1.48%)	~	335ms	348ms	p=0.625 n=6
Req 4 - navto	282ms (± 0.62%)	283ms (± 0.58%)	~	280ms	285ms	p=0.288 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	72ms (± 0.88%)	72ms (± 0.57%)	~	71ms	72ms	p=0.673 n=6
CompilerTSServer - node (v18.10.0, x64)
Req 1 - updateOpen	2,504ms (± 0.74%)	2,504ms (± 0.75%)	~	2,475ms	2,533ms	p=1.000 n=6
Req 2 - geterr	4,029ms (± 0.62%)	4,039ms (± 0.82%)	~	4,007ms	4,073ms	p=0.630 n=6
Req 3 - references	350ms (± 0.97%)	355ms (± 0.86%)	+5ms (+ 1.28%)	353ms	361ms	p=0.043 n=6
Req 4 - navto	290ms (± 0.42%)	288ms (± 0.28%)	~	287ms	289ms	p=0.120 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	68ms (± 1.61%)	67ms (± 0.77%)	~	67ms	68ms	p=0.247 n=6
xstateTSServer - node (v18.10.0, x64)
Req 1 - updateOpen	3,198ms (± 0.41%)	3,196ms (± 0.34%)	~	3,183ms	3,212ms	p=0.810 n=6
Req 2 - geterr	1,638ms (± 1.17%)	1,637ms (± 0.80%)	~	1,621ms	1,654ms	p=0.873 n=6
Req 3 - references	105ms (± 1.17%)	105ms (± 1.17%)	~	103ms	106ms	p=1.000 n=6
Req 4 - navto	358ms (± 1.26%)	357ms (± 0.57%)	~	354ms	360ms	p=1.000 n=6
Req 5 - completionInfo count	3,136 (± 0.00%)	3,136 (± 0.00%)	~	3,136	3,136	p=1.000 n=6
Req 5 - completionInfo	426ms (± 1.53%)	430ms (± 1.13%)	~	424ms	438ms	p=0.374 n=6
Compiler-UnionsTSServer - node (v16.17.1, x64)
Req 1 - updateOpen	2,518ms (± 1.00%)	2,527ms (± 0.54%)	~	2,515ms	2,549ms	p=0.873 n=6
Req 2 - geterr	5,742ms (± 0.48%)	5,765ms (± 0.26%)	~	5,747ms	5,784ms	p=0.173 n=6
Req 3 - references	354ms (± 1.22%)	351ms (± 1.18%)	~	343ms	355ms	p=0.294 n=6
Req 4 - navto	280ms (± 0.89%)	278ms (± 1.01%)	~	273ms	280ms	p=0.305 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 (± 5.51%)	82ms (± 4.25%)	~	77ms	86ms	p=0.806 n=6
CompilerTSServer - node (v16.17.1, x64)
Req 1 - updateOpen	2,688ms (± 0.61%)	2,695ms (± 0.73%)	~	2,664ms	2,712ms	p=0.630 n=6
Req 2 - geterr	4,384ms (± 0.58%)	4,375ms (± 0.38%)	~	4,352ms	4,401ms	p=0.748 n=6
Req 3 - references	363ms (± 0.86%)	364ms (± 1.02%)	~	357ms	367ms	p=0.622 n=6
Req 4 - navto	287ms (± 1.14%)	286ms (± 1.33%)	~	280ms	289ms	p=1.000 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	73ms (± 1.65%)	73ms (± 0.87%)	~	72ms	74ms	p=0.673 n=6
xstateTSServer - node (v16.17.1, x64)
Req 1 - updateOpen	3,371ms (± 0.17%)	3,370ms (± 0.60%)	~	3,355ms	3,410ms	p=0.229 n=6
Req 2 - geterr	1,864ms (± 5.71%)	1,867ms (± 4.71%)	~	1,803ms	2,038ms	p=0.688 n=6
Req 3 - references	111ms (± 2.26%)	113ms (± 2.65%)	~	110ms	118ms	p=0.191 n=6
Req 4 - navto	340ms (± 1.98%)	345ms (± 2.16%)	~	333ms	353ms	p=0.295 n=6
Req 5 - completionInfo count	3,136 (± 0.00%)	3,136 (± 0.00%)	~	3,136	3,136	p=1.000 n=6
Req 5 - completionInfo	434ms (± 0.94%)	435ms (± 0.98%)	~	430ms	441ms	p=0.872 n=6
Compiler-UnionsTSServer - node (v14.15.1, x64)
Req 1 - updateOpen	2,617ms (± 0.65%)	2,622ms (± 0.24%)	~	2,610ms	2,628ms	p=0.198 n=6
Req 2 - geterr	6,082ms (± 0.39%)	6,083ms (± 0.42%)	~	6,050ms	6,119ms	p=1.000 n=6
Req 3 - references	365ms (± 0.35%)	365ms (± 0.22%)	~	364ms	366ms	p=0.558 n=6
Req 4 - navto	279ms (± 1.01%)	277ms (± 0.60%)	~	275ms	279ms	p=0.328 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	98ms (± 4.66%)	101ms (± 0.54%)	~	100ms	101ms	p=0.201 n=6
CompilerTSServer - node (v14.15.1, x64)
Req 1 - updateOpen	2,843ms (± 0.85%)	2,850ms (± 0.61%)	~	2,823ms	2,872ms	p=0.575 n=6
Req 2 - geterr	4,534ms (± 2.25%)	4,621ms (± 2.50%)	~	4,472ms	4,714ms	p=0.128 n=6
Req 3 - references	378ms (± 0.94%)	382ms (± 0.35%)	~	380ms	384ms	p=0.063 n=6
Req 4 - navto	296ms (± 1.20%)	294ms (± 1.42%)	~	290ms	299ms	p=0.291 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	89ms (±10.97%)	83ms (± 1.48%)	~	81ms	84ms	p=0.288 n=6
xstateTSServer - node (v14.15.1, x64)
Req 1 - updateOpen	3,698ms (± 0.76%)	3,687ms (± 0.68%)	~	3,646ms	3,717ms	p=0.810 n=6
Req 2 - geterr	1,871ms (± 1.55%)	1,851ms (± 2.23%)	~	1,805ms	1,908ms	p=0.423 n=6
Req 3 - references	128ms (± 3.39%)	129ms (± 3.52%)	~	124ms	136ms	p=0.809 n=6
Req 4 - navto	376ms (± 0.85%)	378ms (± 1.34%)	~	372ms	386ms	p=0.810 n=6
Req 5 - completionInfo count	3,136 (± 0.00%)	3,136 (± 0.00%)	~	3,136	3,136	p=1.000 n=6
Req 5 - completionInfo	448ms (± 2.32%)	447ms (± 1.59%)	~	439ms	459ms	p=0.630 n=6

System

Machine Name	ts-ci-ubuntu
Platform	linux 5.4.0-135-generic
Architecture	x64
Available Memory	16 GB
Available Memory	15 GB
CPUs	4 × Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz

Hosts

• node (v18.10.0, x64)
• node (v16.17.1, x64)
• node (v14.15.1, x64)

Scenarios

• Compiler-UnionsTSServer - node (v18.10.0, x64)
• Compiler-UnionsTSServer - node (v16.17.1, x64)
• Compiler-UnionsTSServer - node (v14.15.1, x64)
• CompilerTSServer - node (v18.10.0, x64)
• CompilerTSServer - node (v16.17.1, x64)
• CompilerTSServer - node (v14.15.1, x64)
• xstateTSServer - node (v18.10.0, x64)
• xstateTSServer - node (v16.17.1, x64)
• xstateTSServer - node (v14.15.1, x64)

Benchmark	Name	Iterations
Current	52897	6
Baseline	main	6

Startup

Comparison Report - main..52897

Metric	main	52897	Delta	Best	Worst	p-value
tsc-startup - node (v16.17.1, x64)
Execution time	142.17ms (± 0.17%)	143.27ms (± 0.23%)	+1.10ms (+ 0.78%)	142.55ms	149.55ms	p=0.000 n=600
tsserver-startup - node (v16.17.1, x64)
Execution time	226.17ms (± 0.15%)	229.15ms (± 0.39%)	+2.98ms (+ 1.32%)	226.88ms	236.16ms	p=0.000 n=600
tsserverlibrary-startup - node (v16.17.1, x64)
Execution time	228.13ms (± 0.18%)	230.23ms (± 0.31%)	+2.10ms (+ 0.92%)	228.49ms	236.22ms	p=0.000 n=600
typescript-startup - node (v16.17.1, x64)
Execution time	208.92ms (± 0.14%)	210.72ms (± 0.23%)	+1.81ms (+ 0.87%)	209.36ms	215.10ms	p=0.000 n=600

System

Machine Name	ts-ci-ubuntu
Platform	linux 5.4.0-135-generic
Architecture	x64
Available Memory	16 GB
Available Memory	15 GB
CPUs	4 × Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz

Hosts

• node (v16.17.1, x64)

Scenarios

• tsc-startup - node (v16.17.1, x64)
• tsserver-startup - node (v16.17.1, x64)
• tsserverlibrary-startup - node (v16.17.1, x64)
• typescript-startup - node (v16.17.1, x64)

Benchmark	Name	Iterations
Current	52897	6
Baseline	main	6

Developer Information:

Download Benchmark

[Bruce Pascoe (fatcerberus)]

Interestingly, 5.0 nightly catches the case where the comparer returns a literal 2 but not the a - b case. Playground

[Jake Bailey (jakebailey)]

Yeah, then then leftover one is sort of the "known hole" as it has uses. Unfortunate.

[Ron Buckton (rbuckton)]

I've always wondered why we use Comparison rather than just number and do < 0/> 0/=== 0. Is there a performance benefit to using one or the other?

[Ron Buckton (rbuckton)]

I also noticed (but did not change) the fact that we use binary searches for things like import insertion with the assumption that the input is always sorted, but, I don't think this actually turns out to be the case all the time anymore?

Are there places in the code where we're doing a binary search on imports that we haven't previously checked are sorted? IIRC, that's the purpose of detectSortCaseSensitivity.

We have public "branded" types like SortedReadonlyArray and SortedArray that are intended to be used to signal something is sorted, but I've never been a fan of them because they are only sorted in relation to a specific Comparer, which isn't captured in the type. While they may be "sorted" in one respect, you cannot always safely use them as an argument that accepts a "sorted" array without also providing the comparer that was used, which makes the branded type somewhat misleading.

[Jake Bailey (jakebailey)]

I've always wondered why we use Comparison rather than just number and do < 0/> 0/=== 0. Is there a performance benefit to using one or the other?

I doubt it. But I think it's a little easier to understand.

While they may be "sorted" in one respect, you cannot always safely use them as an argument that accepts a "sorted" array without also providing the comparer that was used, which makes the branded type somewhat misleading.

Even so, I do like that even if you don't use the types always, you are forced to cast to a sorted array of you need to use them (depending), which does make one think twice about whether or not the array is actually sorted or not.

[Ron Buckton (rbuckton)]

While they may be "sorted" in one respect, you cannot always safely use them as an argument that accepts a "sorted" array without also providing the comparer that was used, which makes the branded type somewhat misleading.

Even so, I do like that even if you don't use the types always, you are forced to cast to a sorted array of you need to use them (depending), which does make one think twice about whether or not the array is actually sorted or not.

I'd almost rather have a data structure that encapsulates both the sorted array and the comparer, though I'm not sure that's going to be as efficient.