Proposal: Prioritize declaration file resolutions when declaration extension is explicitly specified #58700

andrewbranch · 2024-05-29T16:55:55Z

Alternative to #58553
Fixes #58353

… explicitly specified

andrewbranch · 2024-05-29T16:56:40Z

@typescript-bot test top400
@typescript-bot perf test faster

typescript-bot · 2024-05-29T16:56:43Z

Starting jobs; this comment will be updated as builds start and complete.

Command	Status	Results
`test top400`	✅ Started	✅ Results
`perf test faster`	✅ Started	👀 Results

typescript-bot · 2024-05-29T17:32:29Z

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

Here they are:

tsc

Comparison Report - baseline..pr

_Metric	_baseline	_pr	_Delta	_Best	_Worst	_p-value
_{Compiler-Unions - node (v18.15.0, x64)}
_Errors	₃₀	₃₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_62,153	_62,153	_~	_~	_~	_{p=1.000 n=6}
_Types	_50,242	_50,242	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{193,532k (± 0.92%)}	_{194,147k (± 0.93%)}	_~	_192,277k	_195,824k	_{p=0.575 n=6}
_{Parse Time}	_{1.31s (± 0.64%)}	_{1.31s (± 0.62%)}	_~	_1.29s	_1.31s	_{p=0.673 n=6}
_{Bind Time}	_0.72s	_0.72s	_~	_~	_~	_{p=1.000 n=6}
_{Check Time}	_{9.55s (± 0.37%)}	_{9.56s (± 0.40%)}	_~	_9.50s	_9.61s	_{p=0.808 n=6}
_{Emit Time}	_{2.63s (± 0.82%)}	_{2.63s (± 0.50%)}	_~	_2.62s	_2.65s	_{p=0.805 n=6}
_{Total Time}	_{14.20s (± 0.33%)}	_{14.22s (± 0.28%)}	_~	_14.15s	_14.26s	_{p=0.574 n=6}
_{angular-1 - node (v18.15.0, x64)}
_Errors	₅	₅	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_944,105	_944,105	_~	_~	_~	_{p=1.000 n=6}
_Types	_407,032	_407,032	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{1,222,119k (± 0.00%)}	_{1,222,136k (± 0.00%)}	_~	_1,222,090k	_1,222,159k	_{p=0.630 n=6}
_{Parse Time}	_{6.80s (± 0.61%)}	_{6.79s (± 0.45%)}	_~	_6.74s	_6.82s	_{p=0.687 n=6}
_{Bind Time}	_{1.88s (± 0.43%)}	_{1.87s (± 0.40%)}	_~	_1.86s	_1.88s	_{p=0.120 n=6}
_{Check Time}	_{31.36s (± 0.33%)}	_{31.28s (± 0.46%)}	_~	_31.06s	_31.48s	_{p=0.336 n=6}
_{Emit Time}	_{14.78s (± 0.33%)}	_{14.85s (± 0.53%)}	_~	_14.76s	_14.99s	_{p=0.126 n=6}
_{Total Time}	_{54.82s (± 0.24%)}	_{54.79s (± 0.35%)}	_~	_54.54s	_55.09s	_{p=0.470 n=6}
_{mui-docs - node (v18.15.0, x64)}
_Errors	₅	₅	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_2,053,011	_2,053,011	_~	_~	_~	_{p=1.000 n=6}
_Types	_899,367	_899,367	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{2,065,912k (± 0.01%)}	_{2,065,814k (± 0.01%)}	_~	_2,065,635k	_2,065,966k	_{p=0.128 n=6}
_{Parse Time}	_{6.82s (± 0.13%)}	_{6.83s (± 0.30%)}	_~	_6.79s	_6.85s	_{p=0.285 n=6}
_{Bind Time}	_{2.30s (± 0.59%)}	_{2.32s (± 1.14%)}	_~	_2.29s	_2.36s	_{p=0.510 n=6}
_{Check Time}	_{69.61s (± 0.40%)}	_{69.07s (± 1.42%)}	_~	_67.15s	_69.78s	_{p=0.298 n=6}
_{Emit Time}	_{0.14s (± 2.88%)}	_{0.14s (± 3.60%)}	_~	_0.14s	_0.15s	_{p=0.595 n=6}
_{Total Time}	_{78.88s (± 0.34%)}	_{78.36s (± 1.23%)}	_~	_76.48s	_79.07s	_{p=0.298 n=6}
_{self-build-src - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,226,290	_1,226,291	_{+1 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_260,834	_260,834	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{2,367,745k (± 2.61%)}	_{2,343,518k (± 0.03%)}	_~	_2,342,710k	_2,344,736k	_{p=0.575 n=6}
_{Parse Time}	_{4.94s (± 0.74%)}	_{4.97s (± 1.12%)}	_~	_4.89s	_5.05s	_{p=0.575 n=6}
_{Bind Time}	_{1.91s (± 0.80%)}	_{1.90s (± 0.21%)}	_~	_1.90s	_1.91s	_{p=0.863 n=6}
_{Check Time}	_{33.83s (± 0.35%)}	_{33.82s (± 0.44%)}	_~	_33.63s	_34.01s	_{p=0.688 n=6}
_{Emit Time}	_{2.58s (± 4.23%)}	_{2.55s (± 3.31%)}	_~	_2.44s	_2.66s	_{p=0.810 n=6}
_{Total Time}	_{43.26s (± 0.54%)}	_{43.27s (± 0.34%)}	_~	_43.13s	_43.47s	_{p=0.936 n=6}
_{self-build-src-public-api - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_1,226,290	_1,226,291	_{+1 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_260,834	_260,834	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{2,520,489k (± 3.11%)}	_{2,470,581k (± 3.15%)}	_~	_2,419,154k	_2,571,406k	_{p=0.471 n=6}
_{Parse Time}	_{7.71s (± 1.12%)}	_{7.62s (± 0.65%)}	_~	_7.53s	_7.67s	_{p=0.066 n=6}
_{Bind Time}	_{2.50s (± 0.25%)}	_{2.51s (± 0.60%)}	_~	_2.48s	_2.52s	_{p=0.295 n=6}
_{Check Time}	_{49.86s (± 0.39%)}	_{49.95s (± 0.65%)}	_~	_49.68s	_50.54s	_{p=0.810 n=6}
_{Emit Time}	_{3.83s (± 4.08%)}	_{3.79s (± 3.26%)}	_~	_3.69s	_3.97s	_{p=0.936 n=6}
_{Total Time}	_{63.90s (± 0.48%)}	_{63.89s (± 0.65%)}	_~	_63.51s	_64.63s	_{p=0.689 n=6}
_{self-compiler - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_257,977	_257,978	_{+1 (+ 0.00%)}	_~	_~	_{p=0.001 n=6}
_Types	_104,898	_104,898	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{426,874k (± 0.01%)}	_{426,991k (± 0.01%)}	_{+117k (+ 0.03%)}	_426,929k	_427,084k	_{p=0.005 n=6}
_{Parse Time}	_{3.32s (± 0.78%)}	_{3.34s (± 0.88%)}	_~	_3.31s	_3.39s	_{p=0.332 n=6}
_{Bind Time}	_{1.31s (± 1.15%)}	_{1.32s (± 0.31%)}	_~	_1.31s	_1.32s	_{p=0.730 n=6}
_{Check Time}	_{18.01s (± 0.32%)}	_{17.98s (± 0.36%)}	_~	_17.87s	_18.06s	_{p=0.336 n=6}
_{Emit Time}	_{1.35s (± 1.11%)}	_{1.32s (± 1.63%)}	_{-0.03s (- 2.22%)}	_1.29s	_1.35s	_{p=0.029 n=6}
_{Total Time}	_{23.99s (± 0.27%)}	_{23.96s (± 0.36%)}	_~	_23.85s	_24.06s	_{p=0.572 n=6}
_{ts-pre-modules - node (v18.15.0, x64)}
_Errors	₃₅	₃₅	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_224,565	_224,565	_~	_~	_~	_{p=1.000 n=6}
_Types	_93,734	_93,734	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{369,787k (± 0.02%)}	_{369,824k (± 0.02%)}	_~	_369,725k	_369,924k	_{p=0.471 n=6}
_{Parse Time}	_{2.83s (± 0.96%)}	_{2.84s (± 0.50%)}	_~	_2.82s	_2.86s	_{p=0.746 n=6}
_{Bind Time}	_{1.59s (± 0.92%)}	_{1.59s (± 1.04%)}	_~	_1.56s	_1.60s	_{p=0.511 n=6}
_{Check Time}	_{15.69s (± 0.24%)}	_{15.69s (± 0.17%)}	_~	_15.65s	_15.72s	_{p=0.935 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{20.12s (± 0.11%)}	_{20.12s (± 0.17%)}	_~	_20.07s	_20.17s	_{p=1.000 n=6}
_{vscode - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_2,840,700	_2,840,700	_~	_~	_~	_{p=1.000 n=6}
_Types	_962,692	_962,692	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{3,013,970k (± 0.00%)}	_{3,013,960k (± 0.00%)}	_~	_3,013,922k	_3,014,011k	_{p=1.000 n=6}
_{Parse Time}	_{13.83s (± 0.38%)}	_{13.84s (± 0.24%)}	_~	_13.80s	_13.90s	_{p=0.571 n=6}
_{Bind Time}	_{4.18s (± 2.16%)}	_{4.32s (± 2.94%)}	_{+0.14s (+ 3.35%)}	_4.16s	_4.48s	_{p=0.017 n=6}
_{Check Time}	_{74.69s (± 2.42%)}	_{73.36s (± 0.47%)}	_~	_72.86s	_73.86s	_{p=0.109 n=6}
_{Emit Time}	_{22.32s (± 8.83%)}	_{23.48s (± 0.57%)}	_~	_23.30s	_23.66s	_{p=1.000 n=6}
_{Total Time}	_{115.02s (± 0.28%)}	_{115.00s (± 0.37%)}	_~	_114.36s	_115.47s	_{p=0.936 n=6}
_{webpack - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_266,048	_266,048	_~	_~	_~	_{p=1.000 n=6}
_Types	_108,470	_108,470	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{410,917k (± 0.02%)}	_{410,915k (± 0.01%)}	_~	_410,865k	_410,953k	_{p=0.575 n=6}
_{Parse Time}	_{4.76s (± 0.84%)}	_{4.79s (± 0.56%)}	_~	_4.76s	_4.82s	_{p=0.195 n=6}
_{Bind Time}	_{2.08s (± 0.83%)}	_{2.08s (± 0.90%)}	_~	_2.05s	_2.10s	_{p=0.808 n=6}
_{Check Time}	_{21.07s (± 0.47%)}	_{21.09s (± 0.28%)}	_~	_21.02s	_21.17s	_{p=0.810 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{27.90s (± 0.49%)}	_{27.96s (± 0.26%)}	_~	_27.87s	_28.09s	_{p=1.000 n=6}
_{xstate-main - node (v18.15.0, x64)}
_Errors	₀	₀	_~	_~	_~	_{p=1.000 n=6}
_Symbols	_535,743	_535,743	_~	_~	_~	_{p=1.000 n=6}
_Types	_182,738	_182,738	_~	_~	_~	_{p=1.000 n=6}
_{Memory used}	_{470,456k (± 0.02%)}	_{470,417k (± 0.01%)}	_~	_470,355k	_470,464k	_{p=0.689 n=6}
_{Parse Time}	_{3.94s (± 0.49%)}	_{3.96s (± 0.40%)}	_~	_3.94s	_3.98s	_{p=0.105 n=6}
_{Bind Time}	_{1.49s (± 0.81%)}	_{1.49s (± 1.18%)}	_~	_1.46s	_1.51s	_{p=0.932 n=6}
_{Check Time}	_{22.60s (± 0.34%)}	_{22.59s (± 0.26%)}	_~	_22.50s	_22.65s	_{p=0.873 n=6}
_{Emit Time}	_0.00s	_0.00s	_~	_~	_~	_{p=1.000 n=6}
_{Total Time}	_{28.03s (± 0.30%)}	_{28.04s (± 0.21%)}	_~	_27.97s	_28.11s	_{p=0.810 n=6}

System info unknown

Hosts

node (v18.15.0, x64)

Scenarios

Compiler-Unions - node (v18.15.0, x64)
angular-1 - node (v18.15.0, x64)
mui-docs - node (v18.15.0, x64)
self-build-src - node (v18.15.0, x64)
self-build-src-public-api - node (v18.15.0, x64)
self-compiler - node (v18.15.0, x64)
ts-pre-modules - node (v18.15.0, x64)
vscode - node (v18.15.0, x64)
webpack - node (v18.15.0, x64)
xstate-main - node (v18.15.0, x64)

_Benchmark	_Name	_Iterations
_Current	_pr	₆
_Baseline	_baseline	₆

Developer Information:

Download Benchmarks

typescript-bot · 2024-05-29T18:32:29Z

@andrewbranch Here are the results of running the top 400 repos comparing main and refs/pull/58700/merge:

Everything looks good!

robpalme · 2024-05-31T09:08:52Z

Does this mean that any DTS file importing any relative specifier that ends with *.d.ts will always attempt a non-searching explicit resolution before trying out other options? (Because that sounds great)

andrewbranch · 2024-05-31T16:55:47Z

Yep, exactly. Could you explain how this would be useful for you? The motivation for this in #58353 is pretty narrow and specific.

robpalme · 2024-05-31T18:42:52Z

Could you explain how this would be useful for you?

It's not for immediate use. And it's not something I'd pitch in isolation. But I'm happy to be a supporting voice.

As a general rule, explicit/predictable/simple resolution behavior helps the long-term direction of making TypeScript more flexible/adaptable to custom JS environments. The opposite direction would be for TS have unavoidable implicit behavior, e.g. to bake-in popular conventions such as assuming some kind of extension-searching order, or assuming existence of a package.json, or assuming that dependencies live in a directory called node_modules. Whilst it's appropriate/important/helpful to support mainstream implicit assumptions with almost zero-config, I'd say it is also important to permit escape hatches where advanced users can override them. Escape hatches like this that don't require a flag and don't upset mainstream usage are pure gold.

So this is just one instance of that wider choice. Explicit *.d.ts resolution means we have the option of authoring DTS files in a resilient manner. We already use a custom pipeline for emitting/transforming DTS files, packaging them up, and unpacking dependencies in an ever-growing global dependency cache directory containing immutable per-package per-version declarations. This explicit behavior gives us an escape hatch if we decide to start shipping source/arbitrary files in there too.

robpalme · 2024-06-05T10:19:41Z

As a follow up, we just had a slightly more concrete instance of a situation where explicit resolution would have reduced confusion.

As part of a migration to enable verbatimModuleSyntax, we found an error where an import was relying on index-resolution, even though our runtime does not support that.

// main.ts
import { myType } from "../dir"   // runtime error only when VMS enabled

// main.d.ts (generated)
import { myType } from "../dir"

// dir/index.ts
export type myType = string;

This worked before verbatimModuleSyntax because TypeScript erased the runtime import so this mismatch between compile-time and runtime resolution was never exposed. In the short-term we'll fix this by creating a type-only import that imports the file using an explicit path.

// main.ts
import type { myType } from "../dir/index"

We'd like to have a way to fix this confusion long-term by preventing index-resolution of types both in source and in DTS files via explicit extensions. That ensures that both humans and computers will not get confused about the meaning of an import. And may allow us to switch to a more appropriate TS resolution mode in future.

// main.ts
import type { myType } from "../dir/index.ts"

// main.d.ts (generated)
import type { myType } from "../dir/index.d.ts"

Prioritize declaration file resolutions when declaration extension is…

254259c

… explicitly specified

typescript-bot assigned andrewbranch May 29, 2024

typescript-bot added Author: Team For Milestone Bug PRs that fix a bug with a specific milestone labels May 29, 2024

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Proposal: Prioritize declaration file resolutions when declaration extension is explicitly specified #58700

Proposal: Prioritize declaration file resolutions when declaration extension is explicitly specified #58700

andrewbranch commented May 29, 2024

andrewbranch commented May 29, 2024

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robpalme commented May 31, 2024

andrewbranch commented May 31, 2024

robpalme commented May 31, 2024 •

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robpalme commented Jun 5, 2024

Proposal: Prioritize declaration file resolutions when declaration extension is explicitly specified #58700

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Proposal: Prioritize declaration file resolutions when declaration extension is explicitly specified #58700

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andrewbranch commented May 29, 2024

andrewbranch commented May 29, 2024

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tsc

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robpalme commented May 31, 2024

andrewbranch commented May 31, 2024

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robpalme commented Jun 5, 2024

typescript-bot commented May 29, 2024 •

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