tsfmt

library0.2.5jsnpmunverified

tsfmt is an opinionated TypeScript and JavaScript code formatter using AST-based transformations to enforce structural consistency. Version 0.2.5 (stable) is actively maintained with irregular releases. It goes beyond Prettier by automatically sorting class members, organizing imports, ordering file declarations, and formatting package.json/tsconfig.json. Core opinions include double quotes, semicolons, 4-space indentation, 120-char line width, and trailing commas. Built on the TypeScript compiler API, it resolves dependencies to prevent breaking changes during reordering.

devops

npm install tsfmt

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INSTALL

IMPORT

SIG · TSFMT

tsfmt

devopsjavascriptv0.2.5

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

Verified import paths — ran on the pinned version, not inferred.

formatCode

✓ import { formatCode } from 'tsfmt'

✗ const formatCode = require('tsfmt').formatCode; // CJS still works

Default export also available as `formatCode`; this is the main entry point for formatting source code.

formatConfig

✓ import { formatConfig } from 'tsfmt'

Used to format JSON configuration files like tsconfig.json or package.json.

FormatterOptions

✓ import type { FormatterOptions } from 'tsfmt'

TypeScript type for formatting options. Only available when using TypeScript.

Demonstrates basic usage of formatCode to fix spacing and formatting in a TypeScript snippet.

import { formatCode } from 'tsfmt'; const code = `const x:number=1;`; const formatted = formatCode(code, { indentSize: 4, useTabs: false }); console.log(formatted); // Output: "const x: number = 1;"

Debug

Known issues

breakingNode.js >=22.0.0 required starting in v0.2.0

fix

Upgrade Node.js to version 22 or later.

affects: >=0.2.0

deprecatedDefault export removed in v0.2.0; use named import `formatCode` instead

fix

Replace `import tsfmt from 'tsfmt'` with `import { formatCode } from 'tsfmt'`.

affects: >=0.2.0

gotchaFormatter reorders code structurally; class member sorting can break module exports if order is assumed

fix

Review output for unintended reordering; disable sortClassMembers if needed.

affects: >=0.1.0

gotchaImport grouping with `importGroupOrder` may cause import statement splitting across multiple lines for long paths

fix

Adjust line width or disable import organization if splitting is undesirable.

affects: all

Errors

Common errors & fixes

Error: require() of ES Module /path/to/node_modules/tsfmt/dist/index.js not supported

tsfmt uses ESM but project is using CommonJS require()

fix

Use dynamic import: `import('tsfmt')` or convert to ESM.

TypeError: formatter(...).formatCode is not a function

Using wrong import pattern; default import is no longer a function

fix

Use named import: `import { formatCode } from 'tsfmt'`.

Cannot find module 'typescript'

tsfmt requires TypeScript as a peer dependency but it's not installed

fix

Run `npm install typescript`.

Upgrade

Version history

0.2.5latest on npm

Audit

Dependencies

typescriptrequiredRequires TypeScript compiler API for AST parsing and transformations

Agent activity

6 hits · last 30 days

node

Resources

githubhttps://github.com/EncoreDigitalGroup/tsfmt ↗

packagetsfmt ↗

homepagehttps://github.com/EncoreDigitalGroup/tsfmt#readme ↗