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IntelliSense slow down with large json file
Does this issue occur when all extensions are disabled?: Yes
- VS Code Version: 1.65.2
- OS Version: Ubuntu 20.04.4 LTS
IntelliSense slow down when I set value for compilerOptions->jsx option in tsconfig.json file. Without this option (after restart vscode) I get autocomplete suggestion less then 1 second, with compilerOptions->jsx I get suggestion after 3-4 seconds. CPU i5 8 cores, available RAM more than 10GB.
When initializing js/ts language features in progress IntelliSense work fast
Tried in 1.66.0-insider the result is the same
{
"compilerOptions": {
...
"jsx": "react",
...
},
"exclude": [...]
}
I'm having the same problem (M1 Mac) and I tried the Bisect tool without any success. Can't share my project but I can share my tsconfig:
"compilerOptions": {
/* Visit https://aka.ms/tsconfig.json to read more about this file */
/* Projects */
// "incremental": true, /* Enable incremental compilation */
// "composite": true, /* Enable constraints that allow a TypeScript project to be used with project references. */
// "tsBuildInfoFile": "./", /* Specify the folder for .tsbuildinfo incremental compilation files. */
// "disableSourceOfProjectReferenceRedirect": true, /* Disable preferring source files instead of declaration files when referencing composite projects */
// "disableSolutionSearching": true, /* Opt a project out of multi-project reference checking when editing. */
// "disableReferencedProjectLoad": true, /* Reduce the number of projects loaded automatically by TypeScript. */
/* Language and Environment */
"target": "ESNext", /* Set the JavaScript language version for emitted JavaScript and include compatible library declarations. */
// "lib": [], /* Specify a set of bundled library declaration files that describe the target runtime environment. */
// "jsx": "preserve", /* Specify what JSX code is generated. */
// "experimentalDecorators": true, /* Enable experimental support for TC39 stage 2 draft decorators. */
// "emitDecoratorMetadata": true, /* Emit design-type metadata for decorated declarations in source files. */
// "jsxFactory": "", /* Specify the JSX factory function used when targeting React JSX emit, e.g. 'React.createElement' or 'h' */
// "jsxFragmentFactory": "", /* Specify the JSX Fragment reference used for fragments when targeting React JSX emit e.g. 'React.Fragment' or 'Fragment'. */
// "jsxImportSource": "", /* Specify module specifier used to import the JSX factory functions when using `jsx: react-jsx*`.` */
// "reactNamespace": "", /* Specify the object invoked for `createElement`. This only applies when targeting `react` JSX emit. */
// "noLib": true, /* Disable including any library files, including the default lib.d.ts. */
// "useDefineForClassFields": true, /* Emit ECMAScript-standard-compliant class fields. */
/* Modules */
"module": "ESNext", /* Specify what module code is generated. */
// "rootDir": "./", /* Specify the root folder within your source files. */
"moduleResolution": "node", /* Specify how TypeScript looks up a file from a given module specifier. */
// "baseUrl": "./", /* Specify the base directory to resolve non-relative module names. */
// "paths": {}, /* Specify a set of entries that re-map imports to additional lookup locations. */
// "rootDirs": [], /* Allow multiple folders to be treated as one when resolving modules. */
// "typeRoots": [], /* Specify multiple folders that act like `./node_modules/@types`. */
// "types": [], /* Specify type package names to be included without being referenced in a source file. */
// "allowUmdGlobalAccess": true, /* Allow accessing UMD globals from modules. */
"resolveJsonModule": true, /* Enable importing .json files */
// "noResolve": true, /* Disallow `import`s, `require`s or `<reference>`s from expanding the number of files TypeScript should add to a project. */
/* JavaScript Support */
"allowJs": true, /* Allow JavaScript files to be a part of your program. Use the `checkJS` option to get errors from these files. */
// "checkJs": true, /* Enable error reporting in type-checked JavaScript files. */
// "maxNodeModuleJsDepth": 1, /* Specify the maximum folder depth used for checking JavaScript files from `node_modules`. Only applicable with `allowJs`. */
/* Emit */
// "declaration": true, /* Generate .d.ts files from TypeScript and JavaScript files in your project. */
// "declarationMap": true, /* Create sourcemaps for d.ts files. */
// "emitDeclarationOnly": true, /* Only output d.ts files and not JavaScript files. */
"sourceMap": true, /* Create source map files for emitted JavaScript files. */
// "outFile": "./", /* Specify a file that bundles all outputs into one JavaScript file. If `declaration` is true, also designates a file that bundles all .d.ts output. */
"outDir": "./built", /* Specify an output folder for all emitted files. */
// "removeComments": true, /* Disable emitting comments. */
// "noEmit": true, /* Disable emitting files from a compilation. */
// "importHelpers": true, /* Allow importing helper functions from tslib once per project, instead of including them per-file. */
// "importsNotUsedAsValues": "remove", /* Specify emit/checking behavior for imports that are only used for types */
// "downlevelIteration": true, /* Emit more compliant, but verbose and less performant JavaScript for iteration. */
// "sourceRoot": "", /* Specify the root path for debuggers to find the reference source code. */
// "mapRoot": "", /* Specify the location where debugger should locate map files instead of generated locations. */
// "inlineSourceMap": true, /* Include sourcemap files inside the emitted JavaScript. */
// "inlineSources": true, /* Include source code in the sourcemaps inside the emitted JavaScript. */
// "emitBOM": true, /* Emit a UTF-8 Byte Order Mark (BOM) in the beginning of output files. */
// "newLine": "crlf", /* Set the newline character for emitting files. */
// "stripInternal": true, /* Disable emitting declarations that have `@internal` in their JSDoc comments. */
// "noEmitHelpers": true, /* Disable generating custom helper functions like `__extends` in compiled output. */
// "noEmitOnError": true, /* Disable emitting files if any type checking errors are reported. */
// "preserveConstEnums": true, /* Disable erasing `const enum` declarations in generated code. */
// "declarationDir": "./", /* Specify the output directory for generated declaration files. */
// "preserveValueImports": true, /* Preserve unused imported values in the JavaScript output that would otherwise be removed. */
/* Interop Constraints */
// "isolatedModules": true, /* Ensure that each file can be safely transpiled without relying on other imports. */
// "allowSyntheticDefaultImports": true, /* Allow 'import x from y' when a module doesn't have a default export. */
"esModuleInterop": true, /* Emit additional JavaScript to ease support for importing CommonJS modules. This enables `allowSyntheticDefaultImports` for type compatibility. */
// "preserveSymlinks": true, /* Disable resolving symlinks to their realpath. This correlates to the same flag in node. */
"forceConsistentCasingInFileNames": true, /* Ensure that casing is correct in imports. */
/* Type Checking */
"strict": true, /* Enable all strict type-checking options. */
// "noImplicitAny": true, /* Enable error reporting for expressions and declarations with an implied `any` type.. */
// "strictNullChecks": true, /* When type checking, take into account `null` and `undefined`. */
// "strictFunctionTypes": true, /* When assigning functions, check to ensure parameters and the return values are subtype-compatible. */
// "strictBindCallApply": true, /* Check that the arguments for `bind`, `call`, and `apply` methods match the original function. */
// "strictPropertyInitialization": true, /* Check for class properties that are declared but not set in the constructor. */
// "noImplicitThis": true, /* Enable error reporting when `this` is given the type `any`. */
// "useUnknownInCatchVariables": true, /* Type catch clause variables as 'unknown' instead of 'any'. */
// "alwaysStrict": true, /* Ensure 'use strict' is always emitted. */
// "noUnusedLocals": true, /* Enable error reporting when a local variables aren't read. */
// "noUnusedParameters": true, /* Raise an error when a function parameter isn't read */
// "exactOptionalPropertyTypes": true, /* Interpret optional property types as written, rather than adding 'undefined'. */
// "noImplicitReturns": true, /* Enable error reporting for codepaths that do not explicitly return in a function. */
// "noFallthroughCasesInSwitch": true, /* Enable error reporting for fallthrough cases in switch statements. */
// "noUncheckedIndexedAccess": true, /* Include 'undefined' in index signature results */
// "noImplicitOverride": true, /* Ensure overriding members in derived classes are marked with an override modifier. */
// "noPropertyAccessFromIndexSignature": true, /* Enforces using indexed accessors for keys declared using an indexed type */
// "allowUnusedLabels": true, /* Disable error reporting for unused labels. */
// "allowUnreachableCode": true, /* Disable error reporting for unreachable code. */
/* Completeness */
// "skipDefaultLibCheck": true, /* Skip type checking .d.ts files that are included with TypeScript. */
"skipLibCheck": true /* Skip type checking all .d.ts files. */
},
"exclude": [
"node_modules",
".npm"
],
"include": ["./src"]
}
Wellp... fixed by setting "resolveJsonModule": false... guess it's my import of some huge json files that is causing the issue.
Can't share project too. I found tsx file with a lot of imports (49), if some of imports are commented then all works fine. Tried to find root of issue but this imports has another imports, they has another and etc. I solved this problem by downgrading to the previous version of vscode (1.64.2)
@steve-ross Can you share the json file that causes the problem (feel free to turn the actual contents into gibberish as long as it still demonstrates the issue)
@mjbvz I'll work on getting you a file I can send your way. In the current state I can't send it due to customer data being in the file.
@mjbvz here's one of my json files... pretty big file (had 2 more I was also importing that were 1.5mb each. Pretty sure I noticed the issue with just one though. Attached is my tsconfig and sample json.
Vscode about:
Version: 1.65.2 (Universal)
Commit: c722ca6c7eed3d7987c0d5c3df5c45f6b15e77d1
Date: 2022-03-10T14:33:49.188Z
Electron: 13.5.2
Chromium: 91.0.4472.164
Node.js: 14.16.0
V8: 9.1.269.39-electron.0
OS: Darwin arm64 21.3.0
Thanks @steve-ross
Relevant TS Server log from a JS file that imports that large json file:
//@ts-check
import * as x from './example-subscriptions-clean-emails.json'
// type x. here
I see a ~1 second delay here. Here's what I believe is the relevant request:
Info 87 [11:35:54.591] request:
{
"seq": 8,
"type": "request",
"command": "completionInfo",
"arguments": {
"file": "/Users/matb/Downloads/sample-file-and-config/x.js",
"line": 4,
"offset": 3,
"includeExternalModuleExports": true,
"includeInsertTextCompletions": true,
"triggerCharacter": ".",
"triggerKind": 2
}
}
Info 88 [11:35:54.591] Starting updateGraphWorker: Project: /dev/null/inferredProject1*
Info 89 [11:35:54.594] Finishing updateGraphWorker: Project: /dev/null/inferredProject1* Version: 3 structureChanged: false structureIsReused:: Completely Elapsed: 2.840345025062561ms
Info 90 [11:35:54.594] Different program with same set of files
Info 91 [11:35:54.594] getCompletionData: Get current token: 0.008680999279022217
Info 92 [11:35:54.594] getCompletionData: Is inside comment: 0.01347804069519043
Info 93 [11:35:54.594] getCompletionData: Get previous token: 0.010650992393493652
Info 94 [11:35:54.595] getCompletionsAtPosition: isCompletionListBlocker: 0.0024290084838867188
Info 95 [11:35:55.366] getCompletionData: Semantic work: 771.0405369997025
Info 96 [11:35:55.369] getCompletionsAtPosition: getCompletionEntriesFromSymbols: 2.691716969013214
Perf 97 [11:35:55.369] 8::completionInfo: elapsed time (in milliseconds) 777.5521
This delay happens every time I edit the document and trigger suggestions
steve-ross in the future can you please make sure to open a new issue when reporting problems. I just assumed you were the OP but I think you're talking about a different problem than what @sublite originally reported
@sublite If you're seeing the original problem, please share a project that demonstrates the issue
I finally found this issue after days of this problem. I'd been disabling all of my VSC extensions trying to figure out why Intellisense got so slow for a project of mine.
I finally narrowed it down to this one line in a file:
import megaColors from '../data/colornerd.json';
The JSON is 3 MB. Having that one line makes Intellisense unusably slow for the whole project.
I'm also experiencing very very slow intellisense when importing a json file as big as 39500 lines / 857KB. I guess on my Ryzen 2900x it takes like 20 seconds for the intellisense to come around. When I remove the import, it's back to normal.
I've been investigating this issue, and at least for the example large jsons provided here (by @steve-ross and the json files in @ryancwalsh's paintcolornerd), it seems what is happening is that we're taking too long to type check the very large array in the json file, because in those cases the kind of type checking/inference we do is quadratic on the size of the array literal. This affects intellisense because, in general, when you open or change something in your file that imports the large json, we have to type check it again, and it takes a while. So there's a general slowdown on things like completions, updating errors/red squiggles, quickinfo, etc, that rely on having your file type checked.
- From the checker's implementation side: This happens because, when we are trying to figure out the type of your json array literal, we start by getting the type of each of the json array's elements, and then we try to union them one by one to get the type of the array. But in this process, when we get the type of an array's element and try to add it to the union, we first check if that element's type is already present in the union (more specifically, if it's a subtype of some type already in the union). That process, in the case of this json array literal, turns out to be quadratic in the size of the array.
I'm now going to think about ways in which we could improve this.
@ryancwalsh do you mind providing a link to the 3MB json you mentioned was causing the slowdown?
@gabritto https://github.com/ryancwalsh/paint_color_gallery/blob/main/data/colornerd.json
Update on this bug: I've looked into making type checking array literals faster, but it doesn't look like this would be enough to solve the intellisense slowdown for the examples listed here.
Instead, what I suggest as a fix is the following:
If you're importing a large JSON (array) module with resolveJsonModule set, and you're experiencing slow intellisense in the file(s) that imports this JSON (e.g. slow completions, slow updates to errors/red squiggles, etc), you can set our new flag "allowArbitraryExtensions": true on your tsconfig's compilerOptions, and write a .d.json.ts file with the type of your JSON module.
Example:
index.ts:
import x from './myJson.json';
x[0]; // { prop: number }
myJson.json:
[{ "prop": 1 }]
myJson.d.json.ts:
declare const array: ({ "prop": number })[];
export default array;
Then, when importing the JSON, TS will get the types from your .d.json.ts file instead of type checking the JSON every time your file changes in the editor, making it way faster.
The allowArbitraryExtensions flag is currently only present on the nightly versions, but it will be officially available starting at the 5.0 beta version that we'll release in the next couple weeks.
Curious discovery
Out of curiosity, I decided to try using require instead of import, and to my surprise, it worked. However, when I hovered over the require, I received a warning that said "'require' call may be converted to an import." Despite this, I noticed that if I didn't click on "Quick Fix" to convert the require to an import, IntelliSense no longer experienced delays.
This finding suggests that there may be a difference in IntelliSense performance when using require instead of import in certain situations. It would be interesting to further investigate to understand why this behavior occurs and if there is any technical explanation behind it.
