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Published 20 hours ago • verified publisher icon microsoft

Support for auto-accessor fields from the Stage 3 Decorators proposal

Open rbuckton opened this issue 3 years ago • 19 comments

This PR adds support for accessor field declarations described in the Stage 3 Decorators proposal.

An Auto-Accessor is a field declaration that will be transformed by the runtime into a pair of get and set accessors that access a private backing field:

class C {
  accessor x = 1;
}
// is transformed into
class C {
  // actual field is named `#x accessor storage` so that it isn't user-reachable
  #x_accessor_storage = 1;
  get x() { return this.#x_accessor_storage; }
  set x(value) { this.#x_accessor_storage = value; }
}

When you use --target ESNext, accessor fields will be left as is to be transformed by the runtime. Any earlier --target will result in TypeScript downleveling the accessor field to a compatible runtime implementation.

Auto-Accessor fields have several capabilities:

  • Allows subclasses to override the get/set without a superclass field potentially shadowing the property during initialization.
  • A decorator applied to an auto-accessor receives the get and set accessor pair and can replace them without changing the runtime shape of the class.
  • Native ECMAScript decorators will be able to replace the initializer.

In addition, there are several rules around the use of the accessor keyword:

  • accessor fields require a minimum of --target ES2015, similar to our support for private identifiers (i.e., #x) and for the same reasons (a dependency on WeakMap/WeakSet).
  • accessor may only appear in front of field declarations on a class. It is not supported in interface or object type literals.
  • accessor cannot be used with readonly or declare on the same field declaration.
  • accessor can be used in an ambient class declaration.
  • accessor field declarations can be decorated with TypeScript's legacy decorators (i.e., under --experimentalDecorators). They will behave as if you decorated a get or set declaration (i.e., you will receive a PropertyDescriptor at runtime with both get and set functions).
  • A field explicitly marked with accessor will also be marked with accessor in the output declaration file.
  • An accessor field does not make a class nominal, despite the synthetic private backing field.
  • The TypeScript Symbol for an accessor field is not a SymbolFlags.Property, but rather a SymbolFlags.GetAccessor | SymbolFlags.SetAccessor.

NOTE: This is not an implementation of the full Stage 3 Decorators proposal as that effort is still in progress.

rbuckton avatar Jun 28 '22 01:06 rbuckton

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

rbuckton avatar Jun 28 '22 01:06 rbuckton

Heya @rbuckton, I've started to run the diff-based user code test suite on this PR at b3487dc970d704d63e5b09bcdaa1db15709c9b82. You can monitor the build here.

typescript-bot avatar Jun 28 '22 01:06 typescript-bot

Heya @rbuckton, I've started to run the parallelized Definitely Typed test suite on this PR at b3487dc970d704d63e5b09bcdaa1db15709c9b82. You can monitor the build here.

typescript-bot avatar Jun 28 '22 01:06 typescript-bot

Heya @rbuckton, I've started to run the extended test suite on this PR at b3487dc970d704d63e5b09bcdaa1db15709c9b82. You can monitor the build here.

typescript-bot avatar Jun 28 '22 01:06 typescript-bot

Heya @rbuckton, I've started to run the perf test suite on this PR at b3487dc970d704d63e5b09bcdaa1db15709c9b82. You can monitor the build here.

typescript-bot avatar Jun 28 '22 01:06 typescript-bot

@typescript-bot perf test

rbuckton avatar Jun 28 '22 16:06 rbuckton

Heya @rbuckton, I've started to run the perf test suite on this PR at a37f09a9193db16bbca6ccb9fcb4ffc243d6bafc. You can monitor the build here.

Update: The results are in!

typescript-bot avatar Jun 28 '22 16:06 typescript-bot

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

Here they are:

Comparison Report - main..49705

Metric main 49705 Delta Best Worst
Angular - node (v10.16.3, x64)
Memory used 359,575k (± 0.02%) 359,665k (± 0.02%) +90k (+ 0.02%) 359,557k 359,933k
Parse Time 2.08s (± 0.45%) 2.09s (± 0.49%) +0.01s (+ 0.43%) 2.07s 2.11s
Bind Time 0.90s (± 0.66%) 0.90s (± 0.74%) +0.00s (+ 0.45%) 0.89s 0.91s
Check Time 5.97s (± 0.45%) 5.97s (± 0.46%) -0.00s (- 0.07%) 5.91s 6.04s
Emit Time 6.09s (± 0.54%) 6.18s (± 0.54%) +0.09s (+ 1.50%) 6.12s 6.29s
Total Time 15.03s (± 0.28%) 15.13s (± 0.36%) +0.10s (+ 0.67%) 15.04s 15.31s
Compiler-Unions - node (v10.16.3, x64)
Memory used 206,445k (± 0.04%) 206,542k (± 0.02%) +98k (+ 0.05%) 206,449k 206,633k
Parse Time 0.84s (± 1.07%) 0.83s (± 0.85%) -0.01s (- 0.84%) 0.81s 0.84s
Bind Time 0.53s (± 0.71%) 0.53s (± 1.71%) +0.00s (+ 0.76%) 0.51s 0.55s
Check Time 8.06s (± 0.78%) 8.04s (± 0.46%) -0.01s (- 0.15%) 7.98s 8.13s
Emit Time 2.50s (± 0.62%) 2.52s (± 0.73%) +0.02s (+ 0.88%) 2.48s 2.56s
Total Time 11.91s (± 0.62%) 11.93s (± 0.41%) +0.01s (+ 0.10%) 11.86s 12.06s
Monaco - node (v10.16.3, x64)
Memory used 343,924k (± 0.02%) 344,020k (± 0.02%) +96k (+ 0.03%) 343,897k 344,128k
Parse Time 1.59s (± 0.60%) 1.59s (± 0.14%) -0.01s (- 0.38%) 1.58s 1.59s
Bind Time 0.77s (± 0.67%) 0.77s (± 1.36%) +0.00s (+ 0.26%) 0.76s 0.80s
Check Time 5.95s (± 0.41%) 5.95s (± 0.41%) +0.01s (+ 0.08%) 5.89s 5.99s
Emit Time 3.25s (± 0.81%) 3.30s (± 0.43%) +0.05s (+ 1.54%) 3.27s 3.33s
Total Time 11.56s (± 0.26%) 11.61s (± 0.30%) +0.05s (+ 0.41%) 11.54s 11.69s
TFS - node (v10.16.3, x64)
Memory used 305,148k (± 0.03%) 305,218k (± 0.02%) +71k (+ 0.02%) 305,022k 305,370k
Parse Time 1.28s (± 0.46%) 1.28s (± 0.37%) -0.00s (- 0.31%) 1.27s 1.29s
Bind Time 0.72s (± 0.80%) 0.73s (± 0.80%) +0.01s (+ 0.97%) 0.72s 0.74s
Check Time 5.39s (± 0.34%) 5.40s (± 0.55%) +0.01s (+ 0.26%) 5.33s 5.48s
Emit Time 3.43s (± 0.80%) 3.51s (± 1.31%) +0.08s (+ 2.39%) 3.43s 3.63s
Total Time 10.82s (± 0.36%) 10.91s (± 0.66%) +0.09s (+ 0.85%) 10.77s 11.08s
material-ui - node (v10.16.3, x64)
Memory used 469,038k (± 0.01%) 469,122k (± 0.01%) +85k (+ 0.02%) 468,996k 469,237k
Parse Time 1.82s (± 0.64%) 1.83s (± 0.65%) +0.01s (+ 0.49%) 1.82s 1.87s
Bind Time 0.70s (± 1.72%) 0.69s (± 1.70%) -0.01s (- 1.15%) 0.67s 0.71s
Check Time 14.52s (± 0.93%) 14.50s (± 0.65%) -0.02s (- 0.17%) 14.36s 14.74s
Emit Time 0.00s (± 0.00%) 0.00s (± 0.00%) 0.00s ( NaN%) 0.00s 0.00s
Total Time 17.04s (± 0.82%) 17.02s (± 0.55%) -0.02s (- 0.15%) 16.88s 17.24s
xstate - node (v10.16.3, x64)
Memory used 580,972k (± 1.25%) 584,565k (± 1.68%) +3,594k (+ 0.62%) 577,878k 610,985k
Parse Time 2.59s (± 0.28%) 2.59s (± 0.38%) -0.00s (- 0.00%) 2.57s 2.61s
Bind Time 1.02s (± 0.81%) 1.03s (± 0.56%) +0.00s (+ 0.20%) 1.01s 1.04s
Check Time 1.54s (± 0.60%) 1.54s (± 0.60%) -0.00s (- 0.26%) 1.52s 1.56s
Emit Time 0.07s (± 3.14%) 0.07s (± 4.13%) +0.00s (+ 1.41%) 0.07s 0.08s
Total Time 5.22s (± 0.27%) 5.22s (± 0.30%) +0.00s (+ 0.08%) 5.18s 5.25s
Angular - node (v12.1.0, x64)
Memory used 337,081k (± 0.08%) 337,208k (± 0.02%) +127k (+ 0.04%) 337,082k 337,408k
Parse Time 2.10s (± 0.51%) 2.09s (± 0.55%) -0.00s (- 0.05%) 2.08s 2.13s
Bind Time 0.86s (± 0.77%) 0.87s (± 0.69%) +0.00s (+ 0.35%) 0.85s 0.88s
Check Time 5.78s (± 0.60%) 5.79s (± 0.47%) +0.01s (+ 0.24%) 5.72s 5.84s
Emit Time 6.37s (± 0.80%) 6.44s (± 0.54%) +0.07s (+ 1.12%) 6.37s 6.50s
Total Time 15.10s (± 0.53%) 15.18s (± 0.28%) +0.08s (+ 0.54%) 15.07s 15.28s
Compiler-Unions - node (v12.1.0, x64)
Memory used 194,078k (± 0.07%) 194,166k (± 0.03%) +88k (+ 0.05%) 194,024k 194,323k
Parse Time 0.82s (± 0.57%) 0.82s (± 1.01%) +0.00s (+ 0.61%) 0.81s 0.85s
Bind Time 0.55s (± 0.90%) 0.55s (± 1.09%) 0.00s ( 0.00%) 0.54s 0.56s
Check Time 7.57s (± 0.59%) 7.56s (± 0.61%) -0.01s (- 0.17%) 7.48s 7.72s
Emit Time 2.50s (± 1.00%) 2.56s (± 0.65%) +0.06s (+ 2.36%) 2.53s 2.61s
Total Time 11.43s (± 0.40%) 11.48s (± 0.39%) +0.05s (+ 0.45%) 11.42s 11.63s
Monaco - node (v12.1.0, x64)
Memory used 326,878k (± 0.01%) 327,004k (± 0.02%) +127k (+ 0.04%) 326,895k 327,135k
Parse Time 1.57s (± 0.90%) 1.57s (± 0.65%) -0.01s (- 0.57%) 1.55s 1.59s
Bind Time 0.76s (± 0.63%) 0.76s (± 0.87%) +0.00s (+ 0.40%) 0.75s 0.78s
Check Time 5.77s (± 0.40%) 5.77s (± 0.33%) -0.00s (- 0.02%) 5.74s 5.82s
Emit Time 3.31s (± 0.99%) 3.32s (± 0.33%) +0.01s (+ 0.36%) 3.30s 3.35s
Total Time 11.42s (± 0.40%) 11.42s (± 0.22%) +0.00s (+ 0.03%) 11.38s 11.49s
TFS - node (v12.1.0, x64)
Memory used 289,609k (± 0.05%) 289,827k (± 0.02%) +218k (+ 0.08%) 289,687k 289,958k
Parse Time 1.30s (± 0.51%) 1.29s (± 0.58%) -0.01s (- 1.00%) 1.27s 1.30s
Bind Time 0.72s (± 0.66%) 0.73s (± 0.61%) +0.01s (+ 0.69%) 0.72s 0.74s
Check Time 5.32s (± 0.31%) 5.32s (± 0.35%) -0.01s (- 0.11%) 5.28s 5.38s
Emit Time 3.53s (± 0.91%) 3.54s (± 1.06%) +0.00s (+ 0.06%) 3.43s 3.63s
Total Time 10.88s (± 0.30%) 10.87s (± 0.43%) -0.01s (- 0.10%) 10.78s 11.03s
material-ui - node (v12.1.0, x64)
Memory used 448,120k (± 0.01%) 448,113k (± 0.07%) -7k (- 0.00%) 446,935k 448,419k
Parse Time 1.83s (± 0.45%) 1.82s (± 0.56%) -0.00s (- 0.27%) 1.80s 1.84s
Bind Time 0.68s (± 0.99%) 0.68s (± 0.59%) +0.00s (+ 0.30%) 0.67s 0.69s
Check Time 12.94s (± 0.61%) 12.98s (± 0.80%) +0.03s (+ 0.27%) 12.79s 13.20s
Emit Time 0.00s (± 0.00%) 0.00s (± 0.00%) 0.00s ( NaN%) 0.00s 0.00s
Total Time 15.45s (± 0.52%) 15.48s (± 0.67%) +0.04s (+ 0.23%) 15.29s 15.71s
xstate - node (v12.1.0, x64)
Memory used 546,514k (± 1.31%) 546,666k (± 1.31%) +152k (+ 0.03%) 543,230k 575,660k
Parse Time 2.54s (± 0.42%) 2.54s (± 0.35%) -0.00s (- 0.16%) 2.52s 2.56s
Bind Time 1.03s (± 1.49%) 1.05s (± 1.32%) +0.02s (+ 1.75%) 1.02s 1.07s
Check Time 1.49s (± 0.62%) 1.48s (± 0.40%) -0.00s (- 0.27%) 1.47s 1.50s
Emit Time 0.07s (± 0.00%) 0.07s (± 0.00%) 0.00s ( 0.00%) 0.07s 0.07s
Total Time 5.13s (± 0.35%) 5.14s (± 0.39%) +0.01s (+ 0.21%) 5.11s 5.19s
Angular - node (v14.15.1, x64)
Memory used 335,268k (± 0.01%) 335,379k (± 0.01%) +111k (+ 0.03%) 335,325k 335,439k
Parse Time 2.07s (± 0.84%) 2.07s (± 0.51%) +0.00s (+ 0.19%) 2.05s 2.09s
Bind Time 0.90s (± 0.44%) 0.90s (± 0.54%) +0.01s (+ 0.56%) 0.89s 0.91s
Check Time 5.73s (± 0.44%) 5.75s (± 0.49%) +0.01s (+ 0.24%) 5.70s 5.81s
Emit Time 6.39s (± 0.65%) 6.50s (± 0.54%) +0.11s (+ 1.80%) 6.43s 6.59s
Total Time 15.08s (± 0.47%) 15.22s (± 0.33%) +0.14s (+ 0.94%) 15.11s 15.34s
Compiler-Unions - node (v14.15.1, x64)
Memory used 192,576k (± 0.11%) 192,775k (± 0.02%) +199k (+ 0.10%) 192,671k 192,828k
Parse Time 0.85s (± 0.79%) 0.85s (± 0.68%) +0.00s (+ 0.35%) 0.84s 0.86s
Bind Time 0.57s (± 0.87%) 0.57s (± 0.58%) -0.00s (- 0.87%) 0.56s 0.58s
Check Time 7.66s (± 0.51%) 7.62s (± 0.27%) -0.04s (- 0.51%) 7.58s 7.67s
Emit Time 2.52s (± 0.91%) 2.56s (± 0.73%) +0.04s (+ 1.59%) 2.52s 2.60s
Total Time 11.60s (± 0.40%) 11.60s (± 0.23%) +0.00s (+ 0.01%) 11.53s 11.67s
Monaco - node (v14.15.1, x64)
Memory used 325,635k (± 0.01%) 325,714k (± 0.01%) +79k (+ 0.02%) 325,665k 325,753k
Parse Time 1.58s (± 0.47%) 1.58s (± 0.42%) +0.00s (+ 0.19%) 1.57s 1.60s
Bind Time 0.79s (± 1.07%) 0.80s (± 0.63%) +0.00s (+ 0.51%) 0.79s 0.81s
Check Time 5.68s (± 0.48%) 5.68s (± 0.60%) +0.01s (+ 0.14%) 5.61s 5.78s
Emit Time 3.37s (± 0.80%) 3.41s (± 0.85%) +0.04s (+ 1.34%) 3.36s 3.47s
Total Time 11.41s (± 0.27%) 11.47s (± 0.54%) +0.06s (+ 0.49%) 11.36s 11.63s
TFS - node (v14.15.1, x64)
Memory used 288,777k (± 0.01%) 288,863k (± 0.01%) +86k (+ 0.03%) 288,799k 288,932k
Parse Time 1.34s (± 1.57%) 1.32s (± 1.22%) -0.02s (- 1.64%) 1.29s 1.36s
Bind Time 0.77s (± 4.87%) 0.75s (± 2.28%) -0.02s (- 2.22%) 0.73s 0.81s
Check Time 5.31s (± 0.49%) 5.31s (± 0.38%) +0.00s (+ 0.08%) 5.28s 5.37s
Emit Time 3.57s (± 1.76%) 3.67s (± 0.52%) +0.10s (+ 2.89%) 3.63s 3.71s
Total Time 10.98s (± 0.72%) 11.06s (± 0.36%) +0.07s (+ 0.66%) 10.98s 11.14s
material-ui - node (v14.15.1, x64)
Memory used 446,327k (± 0.01%) 446,406k (± 0.01%) +79k (+ 0.02%) 446,349k 446,443k
Parse Time 1.87s (± 0.54%) 1.87s (± 0.47%) -0.00s (- 0.21%) 1.85s 1.89s
Bind Time 0.73s (± 1.32%) 0.73s (± 0.91%) -0.00s (- 0.14%) 0.71s 0.74s
Check Time 13.24s (± 1.33%) 12.99s (± 0.28%) -0.25s (- 1.90%) 12.90s 13.08s
Emit Time 0.00s (± 0.00%) 0.00s (± 0.00%) 0.00s ( NaN%) 0.00s 0.00s
Total Time 15.84s (± 1.15%) 15.59s (± 0.24%) -0.26s (- 1.62%) 15.52s 15.69s
xstate - node (v14.15.1, x64)
Memory used 541,032k (± 0.00%) 541,209k (± 0.00%) +177k (+ 0.03%) 541,149k 541,273k
Parse Time 2.60s (± 0.48%) 2.60s (± 0.33%) +0.00s (+ 0.08%) 2.58s 2.61s
Bind Time 1.15s (± 1.35%) 1.16s (± 1.10%) +0.01s (+ 1.04%) 1.13s 1.19s
Check Time 1.53s (± 0.39%) 1.53s (± 0.44%) -0.00s (- 0.13%) 1.52s 1.55s
Emit Time 0.07s (± 4.66%) 0.07s (± 4.92%) +0.00s (+ 1.37%) 0.07s 0.08s
Total Time 5.35s (± 0.48%) 5.36s (± 0.28%) +0.01s (+ 0.22%) 5.33s 5.39s
System
Machine Namets-ci-ubuntu
Platformlinux 4.4.0-210-generic
Architecturex64
Available Memory16 GB
Available Memory15 GB
CPUs4 × Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz
Hosts
  • node (v10.16.3, x64)
  • node (v12.1.0, x64)
  • node (v14.15.1, x64)
Scenarios
  • Angular - node (v10.16.3, x64)
  • Angular - node (v12.1.0, x64)
  • Angular - node (v14.15.1, x64)
  • Compiler-Unions - node (v10.16.3, x64)
  • Compiler-Unions - node (v12.1.0, x64)
  • Compiler-Unions - node (v14.15.1, x64)
  • Monaco - node (v10.16.3, x64)
  • Monaco - node (v12.1.0, x64)
  • Monaco - node (v14.15.1, x64)
  • TFS - node (v10.16.3, x64)
  • TFS - node (v12.1.0, x64)
  • TFS - node (v14.15.1, x64)
  • material-ui - node (v10.16.3, x64)
  • material-ui - node (v12.1.0, x64)
  • material-ui - node (v14.15.1, x64)
  • xstate - node (v10.16.3, x64)
  • xstate - node (v12.1.0, x64)
  • xstate - node (v14.15.1, x64)
Benchmark Name Iterations
Current 49705 10
Baseline main 10
Developer Information:

Download Benchmark

typescript-bot avatar Jun 28 '22 17:06 typescript-bot

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

rbuckton avatar Jun 28 '22 17:06 rbuckton

Heya @rbuckton, I've started to run the parallelized Definitely Typed test suite on this PR at 54024cf86daefc2c3f6beee07ba917da2df381ef. You can monitor the build here.

typescript-bot avatar Jun 28 '22 17:06 typescript-bot

Heya @rbuckton, I've started to run the diff-based user code test suite on this PR at 54024cf86daefc2c3f6beee07ba917da2df381ef. You can monitor the build here.

Update: The results are in!

typescript-bot avatar Jun 28 '22 17:06 typescript-bot

Heya @rbuckton, I've started to run the extended test suite on this PR at 54024cf86daefc2c3f6beee07ba917da2df381ef. You can monitor the build here.

typescript-bot avatar Jun 28 '22 17:06 typescript-bot

Heya @rbuckton, 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 avatar Jun 28 '22 17:06 typescript-bot

@rbuckton Great news! no new errors were found between main..refs/pull/49705/merge

typescript-bot avatar Jun 28 '22 17:06 typescript-bot

Why is this a thing? Like, what problem does it actually solve (genuine question, not snark)? The generated accessors don't do anything and unlike, e.g., C#, changing a plain property to an accessor isn't generally an API break...

edit: Oh, I see, it's mostly because decorators will apparently make a distinction between field and accessor.

fatcerberus avatar Jun 28 '22 20:06 fatcerberus

Why is this a thing? Like, what problem does it actually solve (genuine question, not snark)? The generated accessors don't do anything and unlike, e.g., C#, changing a plain property to an accessor isn't generally an API break...

edit: Oh, I see, it's mostly because decorators will apparently make a distinction between field and accessor.

This was a requirement from VM implementers to avoid the potential hidden shape changes that could occur if you were able to convert a field declaration into an accessor dynamically rather than statically. It also helps to avoid issues with public field shadowing in cases like the following, such as with @observe in #48814:

class C {
  // observe attaches an accessor pair to C.prototype, but the field `x` is defined
  // on the instance, shadowing the accessor pair.
  @observe x = 1;
}

// vs
class C {
  // observe can now instead intercept the `{ get, set }` provided to attach its behavior.
  @observe accessor x = 1;
}

rbuckton avatar Jun 29 '22 00:06 rbuckton

What are the assignability rules for auto-accessor fields? I guess that they're the same as a normal class field, but might be missing something.

sandersn avatar Jul 01 '22 18:07 sandersn

They should be treated the same as we would a get/set pair.

rbuckton avatar Jul 01 '22 22:07 rbuckton

Ah, that explains why the code in the checker is with the existing accessor code, not the property declaration code.

sandersn avatar Jul 06 '22 15:07 sandersn

@sandersn can you take another look?

rbuckton avatar Aug 19 '22 18:08 rbuckton

@sandersn I've updated based on your feedback as well as some additional cleanup of the classFields transform. Can you take another look?

rbuckton avatar Sep 02 '22 17:09 rbuckton

@typescript-bot perf test

rbuckton avatar Sep 09 '22 21:09 rbuckton

Heya @rbuckton, I've started to run the perf test suite on this PR at 02405ec1a35b57ac44cb9fadf7552687fa8f548e. You can monitor the build here.

Update: The results are in!

typescript-bot avatar Sep 09 '22 21:09 typescript-bot

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

Here they are:

Compiler

Comparison Report - main..49705
Metric main 49705 Delta Best Worst
Angular - node (v10.16.3, x64)
Memory used 363,293k (± 0.01%) 363,318k (± 0.02%) +25k (+ 0.01%) 363,228k 363,520k
Parse Time 2.08s (± 0.60%) 2.09s (± 0.55%) +0.01s (+ 0.34%) 2.06s 2.12s
Bind Time 0.78s (± 0.74%) 0.79s (± 1.07%) +0.01s (+ 1.02%) 0.78s 0.82s
Check Time 6.17s (± 0.59%) 6.20s (± 0.54%) +0.03s (+ 0.47%) 6.13s 6.29s
Emit Time 5.97s (± 0.56%) 6.04s (± 0.91%) +0.07s (+ 1.14%) 5.97s 6.25s
Total Time 15.01s (± 0.40%) 15.12s (± 0.47%) +0.11s (+ 0.75%) 14.99s 15.32s
Compiler-Unions - node (v10.16.3, x64)
Memory used 206,164k (± 0.03%) 206,233k (± 0.04%) +70k (+ 0.03%) 206,085k 206,536k
Parse Time 0.83s (± 1.06%) 0.83s (± 1.14%) +0.00s (+ 0.12%) 0.82s 0.85s
Bind Time 0.47s (± 0.72%) 0.48s (± 1.46%) +0.01s (+ 1.69%) 0.47s 0.50s
Check Time 8.51s (± 0.64%) 8.51s (± 0.69%) +0.00s (+ 0.06%) 8.40s 8.65s
Emit Time 2.50s (± 1.41%) 2.46s (± 0.98%) -0.05s (- 1.96%) 2.40s 2.50s
Total Time 12.32s (± 0.63%) 12.28s (± 0.45%) -0.04s (- 0.30%) 12.17s 12.41s
Monaco - node (v10.16.3, x64)
Memory used 344,666k (± 0.02%) 344,758k (± 0.02%) +92k (+ 0.03%) 344,463k 344,862k
Parse Time 1.60s (± 0.74%) 1.61s (± 0.60%) +0.01s (+ 0.81%) 1.59s 1.63s
Bind Time 0.70s (± 0.57%) 0.70s (± 0.84%) +0.00s (+ 0.72%) 0.69s 0.72s
Check Time 6.26s (± 0.51%) 6.23s (± 0.60%) -0.02s (- 0.37%) 6.17s 6.30s
Emit Time 3.23s (± 0.78%) 3.20s (± 0.78%) -0.03s (- 1.02%) 3.16s 3.28s
Total Time 11.78s (± 0.35%) 11.75s (± 0.46%) -0.04s (- 0.30%) 11.62s 11.85s
TFS - node (v10.16.3, x64)
Memory used 305,891k (± 0.02%) 305,965k (± 0.02%) +74k (+ 0.02%) 305,845k 306,147k
Parse Time 1.28s (± 0.53%) 1.29s (± 0.67%) +0.00s (+ 0.31%) 1.27s 1.31s
Bind Time 0.67s (± 0.99%) 0.67s (± 0.50%) -0.00s (- 0.45%) 0.66s 0.68s
Check Time 5.50s (± 0.67%) 5.51s (± 0.48%) +0.01s (+ 0.15%) 5.46s 5.59s
Emit Time 3.44s (± 1.64%) 3.35s (± 1.39%) -0.09s (- 2.59%) 3.23s 3.45s
Total Time 10.90s (± 0.56%) 10.82s (± 0.41%) -0.08s (- 0.72%) 10.68s 10.91s
material-ui - node (v10.16.3, x64)
Memory used 459,020k (± 0.01%) 459,171k (± 0.01%) +151k (+ 0.03%) 459,080k 459,290k
Parse Time 1.82s (± 0.66%) 1.84s (± 0.55%) +0.03s (+ 1.54%) 1.82s 1.86s
Bind Time 0.59s (± 1.72%) 0.57s (± 1.30%) -0.01s (- 2.22%) 0.56s 0.60s
Check Time 15.68s (± 0.57%) 15.83s (± 0.70%) +0.15s (+ 0.96%) 15.54s 16.02s
Emit Time 0.00s (± 0.00%) 0.00s (± 0.00%) 0.00s ( NaN%) 0.00s 0.00s
Total Time 18.09s (± 0.52%) 18.25s (± 0.64%) +0.16s (+ 0.90%) 17.95s 18.44s
xstate - node (v10.16.3, x64)
Memory used 583,805k (± 0.02%) 584,038k (± 0.02%) +233k (+ 0.04%) 583,763k 584,220k
Parse Time 2.60s (± 0.51%) 2.61s (± 0.35%) +0.02s (+ 0.58%) 2.59s 2.63s
Bind Time 0.92s (± 0.65%) 0.92s (± 0.61%) +0.00s (+ 0.22%) 0.91s 0.93s
Check Time 1.60s (± 0.66%) 1.61s (± 0.58%) +0.01s (+ 0.88%) 1.58s 1.63s
Emit Time 0.07s (± 0.00%) 0.07s (± 4.13%) +0.00s (+ 2.86%) 0.07s 0.08s
Total Time 5.18s (± 0.32%) 5.21s (± 0.30%) +0.04s (+ 0.70%) 5.18s 5.24s
Angular - node (v12.1.0, x64)
Memory used 340,776k (± 0.02%) 340,766k (± 0.02%) -10k (- 0.00%) 340,623k 340,885k
Parse Time 2.07s (± 0.39%) 2.07s (± 0.79%) +0.00s (+ 0.05%) 2.04s 2.12s
Bind Time 0.77s (± 0.58%) 0.77s (± 0.52%) -0.00s (- 0.13%) 0.76s 0.78s
Check Time 5.82s (± 0.53%) 5.84s (± 0.39%) +0.02s (+ 0.40%) 5.79s 5.89s
Emit Time 6.22s (± 0.66%) 6.20s (± 0.57%) -0.02s (- 0.32%) 6.11s 6.27s
Total Time 14.88s (± 0.35%) 14.89s (± 0.35%) +0.00s (+ 0.03%) 14.80s 15.01s
Compiler-Unions - node (v12.1.0, x64)
Memory used 194,008k (± 0.53%) 193,158k (± 0.42%) -850k (- 0.44%) 190,734k 194,087k
Parse Time 0.82s (± 0.63%) 0.83s (± 0.70%) +0.01s (+ 0.73%) 0.81s 0.84s
Bind Time 0.48s (± 1.22%) 0.47s (± 1.04%) -0.00s (- 0.63%) 0.46s 0.48s
Check Time 6.68s (± 0.43%) 6.74s (± 0.78%) +0.06s (+ 0.82%) 6.59s 6.86s
Emit Time 2.48s (± 1.08%) 2.42s (± 1.70%) -0.06s (- 2.26%) 2.35s 2.53s
Total Time 10.46s (± 0.33%) 10.46s (± 0.78%) +0.00s (+ 0.02%) 10.28s 10.67s
Monaco - node (v12.1.0, x64)
Memory used 327,661k (± 0.06%) 327,705k (± 0.06%) +44k (+ 0.01%) 326,934k 327,858k
Parse Time 1.58s (± 1.30%) 1.58s (± 0.67%) +0.00s (+ 0.25%) 1.56s 1.61s
Bind Time 0.70s (± 1.11%) 0.70s (± 0.64%) -0.00s (- 0.14%) 0.69s 0.71s
Check Time 5.82s (± 0.75%) 5.83s (± 0.64%) +0.01s (+ 0.19%) 5.74s 5.90s
Emit Time 3.30s (± 1.38%) 3.29s (± 1.26%) -0.01s (- 0.42%) 3.21s 3.40s
Total Time 11.41s (± 0.72%) 11.40s (± 0.62%) -0.01s (- 0.04%) 11.22s 11.53s
TFS - node (v12.1.0, x64)
Memory used 290,365k (± 0.07%) 290,637k (± 0.03%) +271k (+ 0.09%) 290,442k 290,807k
Parse Time 1.29s (± 0.64%) 1.29s (± 0.56%) +0.00s (+ 0.16%) 1.28s 1.31s
Bind Time 0.67s (± 1.09%) 0.67s (± 0.66%) +0.00s (+ 0.60%) 0.66s 0.68s
Check Time 5.38s (± 0.49%) 5.37s (± 0.43%) -0.01s (- 0.24%) 5.32s 5.41s
Emit Time 3.49s (± 1.18%) 3.42s (± 0.89%) -0.07s (- 1.98%) 3.33s 3.48s
Total Time 10.82s (± 0.29%) 10.74s (± 0.41%) -0.08s (- 0.72%) 10.65s 10.86s
material-ui - node (v12.1.0, x64)
Memory used 437,911k (± 0.11%) 438,308k (± 0.02%) +397k (+ 0.09%) 438,099k 438,513k
Parse Time 1.81s (± 0.29%) 1.82s (± 0.41%) +0.01s (+ 0.44%) 1.80s 1.83s
Bind Time 0.55s (± 0.81%) 0.55s (± 0.54%) +0.00s (+ 0.00%) 0.55s 0.56s
Check Time 12.84s (± 0.54%) 12.76s (± 0.55%) -0.08s (- 0.59%) 12.68s 12.98s
Emit Time 0.00s (± 0.00%) 0.00s (± 0.00%) 0.00s ( NaN%) 0.00s 0.00s
Total Time 15.20s (± 0.47%) 15.13s (± 0.45%) -0.07s (- 0.44%) 15.05s 15.35s
xstate - node (v12.1.0, x64)
Memory used 548,925k (± 0.01%) 549,180k (± 0.01%) +255k (+ 0.05%) 549,065k 549,302k
Parse Time 2.54s (± 0.36%) 2.53s (± 0.50%) -0.01s (- 0.28%) 2.51s 2.56s
Bind Time 0.89s (± 0.75%) 0.89s (± 1.19%) +0.01s (+ 0.56%) 0.88s 0.93s
Check Time 1.47s (± 0.57%) 1.48s (± 0.49%) +0.01s (+ 0.48%) 1.46s 1.49s
Emit Time 0.07s (± 0.00%) 0.07s (± 0.00%) 0.00s ( 0.00%) 0.07s 0.07s
Total Time 4.97s (± 0.28%) 4.97s (± 0.40%) -0.00s (- 0.06%) 4.94s 5.03s
Angular - node (v14.15.1, x64)
Memory used 338,830k (± 0.01%) 338,933k (± 0.01%) +104k (+ 0.03%) 338,888k 338,981k
Parse Time 2.06s (± 0.72%) 2.07s (± 1.56%) +0.01s (+ 0.63%) 2.04s 2.20s
Bind Time 0.79s (± 0.70%) 0.80s (± 0.43%) +0.00s (+ 0.63%) 0.79s 0.80s
Check Time 5.81s (± 0.50%) 5.84s (± 0.68%) +0.03s (+ 0.45%) 5.76s 5.93s
Emit Time 6.18s (± 0.55%) 6.22s (± 0.79%) +0.04s (+ 0.66%) 6.13s 6.38s
Total Time 14.85s (± 0.30%) 14.93s (± 0.52%) +0.09s (+ 0.58%) 14.82s 15.19s
Compiler-Unions - node (v14.15.1, x64)
Memory used 192,987k (± 0.38%) 190,136k (± 0.01%) -2,852k (- 1.48%) 190,098k 190,170k
Parse Time 0.85s (± 0.40%) 0.85s (± 0.55%) +0.00s (+ 0.35%) 0.84s 0.86s
Bind Time 0.48s (± 0.70%) 0.49s (± 0.75%) +0.00s (+ 0.62%) 0.48s 0.49s
Check Time 6.74s (± 0.50%) 6.77s (± 0.55%) +0.02s (+ 0.31%) 6.66s 6.82s
Emit Time 2.40s (± 0.92%) 2.38s (± 0.84%) -0.02s (- 0.75%) 2.34s 2.42s
Total Time 10.48s (± 0.37%) 10.49s (± 0.38%) +0.01s (+ 0.06%) 10.40s 10.56s
Monaco - node (v14.15.1, x64)
Memory used 326,529k (± 0.01%) 326,560k (± 0.01%) +30k (+ 0.01%) 326,506k 326,606k
Parse Time 1.58s (± 0.86%) 1.58s (± 0.74%) -0.00s (- 0.19%) 1.55s 1.60s
Bind Time 0.72s (± 0.50%) 0.73s (± 1.20%) +0.01s (+ 0.83%) 0.72s 0.76s
Check Time 5.71s (± 0.38%) 5.74s (± 0.45%) +0.03s (+ 0.54%) 5.68s 5.80s
Emit Time 3.31s (± 0.68%) 3.33s (± 0.75%) +0.02s (+ 0.70%) 3.28s 3.38s
Total Time 11.32s (± 0.37%) 11.37s (± 0.31%) +0.05s (+ 0.49%) 11.27s 11.44s
TFS - node (v14.15.1, x64)
Memory used 289,660k (± 0.01%) 289,685k (± 0.01%) +25k (+ 0.01%) 289,616k 289,735k
Parse Time 1.30s (± 0.50%) 1.30s (± 0.54%) -0.00s (- 0.08%) 1.29s 1.32s
Bind Time 0.79s (± 0.66%) 0.78s (± 2.36%) -0.01s (- 1.14%) 0.73s 0.81s
Check Time 5.33s (± 0.41%) 5.33s (± 0.46%) +0.00s (+ 0.04%) 5.29s 5.40s
Emit Time 3.56s (± 0.56%) 3.55s (± 1.39%) -0.01s (- 0.20%) 3.50s 3.74s
Total Time 10.99s (± 0.31%) 10.97s (± 0.74%) -0.02s (- 0.14%) 10.81s 11.24s
material-ui - node (v14.15.1, x64)
Memory used 436,273k (± 0.06%) 436,436k (± 0.06%) +163k (+ 0.04%) 435,358k 436,622k
Parse Time 1.86s (± 0.44%) 1.86s (± 0.65%) +0.00s (+ 0.22%) 1.84s 1.89s
Bind Time 0.58s (± 0.62%) 0.58s (± 0.77%) -0.00s (- 0.34%) 0.57s 0.59s
Check Time 12.90s (± 0.62%) 12.98s (± 0.71%) +0.08s (+ 0.62%) 12.77s 13.19s
Emit Time 0.00s (± 0.00%) 0.00s (± 0.00%) 0.00s ( NaN%) 0.00s 0.00s
Total Time 15.34s (± 0.55%) 15.43s (± 0.64%) +0.08s (+ 0.55%) 15.21s 15.66s
xstate - node (v14.15.1, x64)
Memory used 546,739k (± 0.00%) 546,977k (± 0.00%) +238k (+ 0.04%) 546,942k 547,028k
Parse Time 2.59s (± 0.59%) 2.61s (± 0.49%) +0.02s (+ 0.73%) 2.59s 2.65s
Bind Time 0.97s (± 0.72%) 0.97s (± 0.78%) +0.00s (+ 0.52%) 0.96s 1.00s
Check Time 1.51s (± 0.45%) 1.52s (± 0.62%) +0.00s (+ 0.33%) 1.50s 1.54s
Emit Time 0.07s (± 4.13%) 0.07s (± 0.00%) -0.00s (- 2.78%) 0.07s 0.07s
Total Time 5.15s (± 0.29%) 5.18s (± 0.41%) +0.03s (+ 0.58%) 5.14s 5.24s
System
Machine Namets-ci-ubuntu
Platformlinux 4.4.0-210-generic
Architecturex64
Available Memory16 GB
Available Memory15 GB
CPUs4 × Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz
Hosts
  • node (v10.16.3, x64)
  • node (v12.1.0, x64)
  • node (v14.15.1, x64)
Scenarios
  • Angular - node (v10.16.3, x64)
  • Angular - node (v12.1.0, x64)
  • Angular - node (v14.15.1, x64)
  • Compiler-Unions - node (v10.16.3, x64)
  • Compiler-Unions - node (v12.1.0, x64)
  • Compiler-Unions - node (v14.15.1, x64)
  • Monaco - node (v10.16.3, x64)
  • Monaco - node (v12.1.0, x64)
  • Monaco - node (v14.15.1, x64)
  • TFS - node (v10.16.3, x64)
  • TFS - node (v12.1.0, x64)
  • TFS - node (v14.15.1, x64)
  • material-ui - node (v10.16.3, x64)
  • material-ui - node (v12.1.0, x64)
  • material-ui - node (v14.15.1, x64)
  • xstate - node (v10.16.3, x64)
  • xstate - node (v12.1.0, x64)
  • xstate - node (v14.15.1, x64)
Benchmark Name Iterations
Current 49705 10
Baseline main 10

TSServer

Comparison Report - main..49705
Metric main 49705 Delta Best Worst
Compiler-UnionsTSServer - node (v10.16.3, x64)
Req 1 - updateOpen 1,402ms (± 0.65%) 1,407ms (± 0.62%) +5ms (+ 0.34%) 1,387ms 1,426ms
Req 2 - geterr 4,111ms (± 0.58%) 4,099ms (± 0.70%) -13ms (- 0.30%) 4,031ms 4,142ms
Req 3 - references 230ms (± 1.27%) 230ms (± 0.90%) -1ms (- 0.30%) 224ms 234ms
Req 4 - navto 173ms (± 0.79%) 175ms (± 1.06%) +1ms (+ 0.69%) 170ms 180ms
Req 5 - completionInfo count 1,356 (± 0.00%) 1,356 (± 0.00%) 0 ( 0.00%) 1,356 1,356
Req 5 - completionInfo 96ms (± 2.23%) 91ms (± 8.11%) 🟩-5ms (- 5.63%) 62ms 97ms
CompilerTSServer - node (v10.16.3, x64)
Req 1 - updateOpen 1,495ms (± 0.67%) 1,501ms (± 0.40%) +6ms (+ 0.39%) 1,489ms 1,514ms
Req 2 - geterr 2,253ms (± 0.67%) 2,258ms (± 0.41%) +4ms (+ 0.20%) 2,234ms 2,277ms
Req 3 - references 242ms (± 0.79%) 245ms (± 0.72%) +3ms (+ 1.28%) 242ms 251ms
Req 4 - navto 185ms (± 0.54%) 185ms (± 0.67%) -1ms (- 0.38%) 183ms 187ms
Req 5 - completionInfo count 1,518 (± 0.00%) 1,518 (± 0.00%) 0 ( 0.00%) 1,518 1,518
Req 5 - completionInfo 62ms (± 1.97%) 62ms (± 2.78%) +0ms (+ 0.49%) 58ms 67ms
xstateTSServer - node (v10.16.3, x64)
Req 1 - updateOpen 2,090ms (± 0.44%) 2,097ms (± 0.46%) +7ms (+ 0.34%) 2,077ms 2,117ms
Req 2 - geterr 794ms (± 0.38%) 796ms (± 0.69%) +2ms (+ 0.25%) 781ms 808ms
Req 3 - references 101ms (± 2.93%) 99ms (± 1.61%) -2ms (- 1.97%) 95ms 103ms
Req 4 - navto 235ms (± 1.26%) 232ms (± 0.76%) -3ms (- 1.28%) 227ms 235ms
Req 5 - completionInfo count 3,301 (± 0.00%) 3,301 (± 0.00%) 0 ( 0.00%) 3,301 3,301
Req 5 - completionInfo 280ms (± 1.16%) 280ms (± 1.22%) +0ms (+ 0.04%) 271ms 286ms
Compiler-UnionsTSServer - node (v12.1.0, x64)
Req 1 - updateOpen 1,402ms (± 0.73%) 1,406ms (± 0.57%) +4ms (+ 0.25%) 1,392ms 1,427ms
Req 2 - geterr 3,368ms (± 0.39%) 3,394ms (± 0.73%) +26ms (+ 0.77%) 3,343ms 3,457ms
Req 3 - references 219ms (± 0.92%) 219ms (± 0.97%) +0ms (+ 0.18%) 215ms 225ms
Req 4 - navto 160ms (± 0.85%) 160ms (± 1.04%) -0ms (- 0.13%) 156ms 165ms
Req 5 - completionInfo count 1,356 (± 0.00%) 1,356 (± 0.00%) 0 ( 0.00%) 1,356 1,356
Req 5 - completionInfo 60ms (± 4.77%) 59ms (± 4.03%) -1ms (- 1.99%) 55ms 65ms
CompilerTSServer - node (v12.1.0, x64)
Req 1 - updateOpen 1,487ms (± 0.61%) 1,496ms (± 0.71%) +9ms (+ 0.59%) 1,479ms 1,529ms
Req 2 - geterr 2,168ms (± 0.59%) 2,159ms (± 0.38%) -9ms (- 0.42%) 2,145ms 2,174ms
Req 3 - references 236ms (± 1.16%) 235ms (± 0.71%) -0ms (- 0.17%) 233ms 240ms
Req 4 - navto 172ms (± 1.00%) 170ms (± 0.89%) -2ms (- 1.16%) 166ms 174ms
Req 5 - completionInfo count 1,518 (± 0.00%) 1,518 (± 0.00%) 0 ( 0.00%) 1,518 1,518
Req 5 - completionInfo 59ms (± 2.93%) 60ms (± 3.17%) +1ms (+ 2.20%) 57ms 65ms
xstateTSServer - node (v12.1.0, x64)
Req 1 - updateOpen 2,036ms (± 0.25%) 2,035ms (± 0.40%) -1ms (- 0.03%) 2,011ms 2,054ms
Req 2 - geterr 747ms (± 0.45%) 744ms (± 0.48%) -3ms (- 0.41%) 733ms 750ms
Req 3 - references 68ms (± 1.01%) 67ms (± 1.25%) -1ms (- 1.48%) 65ms 68ms
Req 4 - navto 223ms (± 1.30%) 224ms (± 1.35%) +0ms (+ 0.13%) 212ms 226ms
Req 5 - completionInfo count 3,301 (± 0.00%) 3,301 (± 0.00%) 0 ( 0.00%) 3,301 3,301
Req 5 - completionInfo 275ms (± 1.08%) 276ms (± 1.07%) +0ms (+ 0.11%) 269ms 283ms
Compiler-UnionsTSServer - node (v14.15.1, x64)
Req 1 - updateOpen 1,441ms (± 0.57%) 1,446ms (± 0.44%) +5ms (+ 0.37%) 1,435ms 1,465ms
Req 2 - geterr 3,518ms (± 1.04%) 3,517ms (± 0.45%) -1ms (- 0.02%) 3,480ms 3,557ms
Req 3 - references 231ms (± 0.78%) 231ms (± 0.91%) +0ms (+ 0.13%) 227ms 238ms
Req 4 - navto 171ms (± 0.95%) 171ms (± 0.61%) -0ms (- 0.23%) 168ms 173ms
Req 5 - completionInfo count 1,356 (± 0.00%) 1,356 (± 0.00%) 0 ( 0.00%) 1,356 1,356
Req 5 - completionInfo 55ms (± 1.18%) 60ms (± 7.13%) +5ms (+ 9.49%) 54ms 67ms
CompilerTSServer - node (v14.15.1, x64)
Req 1 - updateOpen 1,512ms (± 0.55%) 1,519ms (± 0.56%) +7ms (+ 0.46%) 1,501ms 1,532ms
Req 2 - geterr 2,310ms (± 0.53%) 2,312ms (± 0.52%) +2ms (+ 0.10%) 2,284ms 2,335ms
Req 3 - references 242ms (± 0.61%) 243ms (± 0.72%) +1ms (+ 0.50%) 240ms 247ms
Req 4 - navto 178ms (± 0.67%) 178ms (± 0.70%) +0ms (+ 0.11%) 175ms 181ms
Req 5 - completionInfo count 1,518 (± 0.00%) 1,518 (± 0.00%) 0 ( 0.00%) 1,518 1,518
Req 5 - completionInfo 55ms (± 0.90%) 55ms (± 1.18%) +0ms (+ 0.37%) 54ms 57ms
xstateTSServer - node (v14.15.1, x64)
Req 1 - updateOpen 2,133ms (± 0.63%) 2,142ms (± 0.48%) +9ms (+ 0.40%) 2,124ms 2,172ms
Req 2 - geterr 767ms (± 0.45%) 764ms (± 0.33%) -3ms (- 0.39%) 759ms 769ms
Req 3 - references 65ms (± 1.02%) 66ms (± 1.74%) +1ms (+ 1.53%) 64ms 69ms
Req 4 - navto 229ms (± 0.75%) 228ms (± 0.53%) -1ms (- 0.52%) 225ms 231ms
Req 5 - completionInfo count 3,301 (± 0.00%) 3,301 (± 0.00%) 0 ( 0.00%) 3,301 3,301
Req 5 - completionInfo 279ms (± 0.57%) 277ms (± 0.60%) -3ms (- 0.93%) 274ms 281ms
System
Machine Namets-ci-ubuntu
Platformlinux 4.4.0-210-generic
Architecturex64
Available Memory16 GB
Available Memory15 GB
CPUs4 × Intel(R) Core(TM) i7-4770 CPU @ 3.40GHz
Hosts
  • node (v10.16.3, x64)
  • node (v12.1.0, x64)
  • node (v14.15.1, x64)
Scenarios
  • Compiler-UnionsTSServer - node (v10.16.3, x64)
  • Compiler-UnionsTSServer - node (v12.1.0, x64)
  • Compiler-UnionsTSServer - node (v14.15.1, x64)
  • CompilerTSServer - node (v10.16.3, x64)
  • CompilerTSServer - node (v12.1.0, x64)
  • CompilerTSServer - node (v14.15.1, x64)
  • xstateTSServer - node (v10.16.3, x64)
  • xstateTSServer - node (v12.1.0, x64)
  • xstateTSServer - node (v14.15.1, x64)
Benchmark Name Iterations
Current 49705 10
Baseline main 10
Developer Information:

Download Benchmark

typescript-bot avatar Sep 09 '22 23:09 typescript-bot

accessor cannot be used with readonly or declare on the same field declaration.

Hi, I just noticed that using TypeScript 4.9.3,

class Foo {
    accessor readonly foo: number = 5;
}

does not give an error. It is simply ignored: Playground example "... cannot be used" sounds like it should result in an error. Is this worth being reported as an issue?

fwienber avatar Dec 08 '22 10:12 fwienber

Also,

class Foo {
    accessor declare foo: number;
}

works as I would expect. Is there any reason to not support it?

fwienber avatar Dec 08 '22 10:12 fwienber

accessor cannot be used with readonly or declare on the same field declaration.

Hi, I just noticed that using TypeScript 4.9.3,

class Foo {
    accessor readonly foo: number = 5;
}

does not give an error. It is simply ignored: Playground example "... cannot be used" sounds like it should result in an error. Is this worth being reported as an issue?

Yes, this should be an error.

Also,

class Foo {
    accessor declare foo: number;
}

works as I would expect. Is there any reason to not support it?

declare was only intended for normal fields as a special case to work around issues with --useDefineForClassProperties and legacy decorators. It isn't intended to work for accessors since they are defined on the prototype. This should be an error.

rbuckton avatar Dec 08 '22 14:12 rbuckton

Thanks for the quick response, then I'm going to create an issue for that!

fwienber avatar Dec 08 '22 16:12 fwienber

Very naive question: Is there a reason not to implement a similar keyword for public readonly properties which would do the same, but without a setter?

EDIT: I guess the keyword for readonly properties would be readonly :)
First thought is, the transpiler could, if target > ES2015, transform

class C {
    readonly x = 1;
}

into

class C {
    #x_accessor_storage = 1;
    get x() { return this.#x_accessor_storage; }
}

But that would be a very breaking change; which could be enabled by a --strictReadonly flag in the compiler options... Which would be a lot of work just for syntactic sugar

ClementValot avatar Dec 20 '22 19:12 ClementValot

Is there a reason not to implement a similar keyword for public readonly properties which would do the same, but without a setter?

More generally, is there a reason that readonly accessor isn't supported?

wycats avatar Jan 04 '23 21:01 wycats