Is this the very same default formatter included in vscode?

[softmarshmallow]

Is it? or is it just following config format from vscode. I'm looking for which project is the default ts formatter for typescript

[user72356]

Did you find out which one is the default formatter? I doubt this one is it, this project looks dead. No commit in 4 years.

[unilynx]

As far as I can tell the actual TS Formatter is here: https://github.com/microsoft/TypeScript/blob/main/src/services/formatting/formatting.ts

and not depending on this package.

VSCode invokes it here: https://github.com/microsoft/vscode/blob/709aafe0150fcfc3819fe265f5a91cb338aeafca/build/lib/formatter.ts#L67

So actually it's the other way around: this package mimicks the above at https://github.com/vvakame/typescript-formatter/blob/7764258ad42ac65071399840d1b8701868510ca7/lib/formatter.ts

Given all that, and having spent too much time debugging host.fileExists is not a function I'm now replacing my use of typescript-formatter with

import ts from "typescript";


// This code is based on the MIT Licensed https://github.com/vvakame/typescript-formatter originally Copyright © 2015 Masahiro Wakame
class MockedLanguageServiceHost implements ts.LanguageServiceHost {
  files: ts.MapLike<ts.IScriptSnapshot> = {};
  addFile(fileName: string, text: string) {
    this.files[fileName] = ts.ScriptSnapshot.fromString(text);
  }

  getCompilationSettings = () => ts.getDefaultCompilerOptions();
  getScriptFileNames = () => Object.keys(this.files);
  getScriptVersion = (_fileName: string) => "0";
  getScriptSnapshot = (fileName: string) => this.files[fileName];
  getCurrentDirectory = () => process.cwd();
  getDefaultLibFileName = (options: ts.CompilerOptions) => ts.getDefaultLibFilePath(options);
  readFile = (fileName: string) => this.files[fileName]?.getText(0, this.files[fileName].getLength()) ?? "";
  fileExists = (fileName: string) => fileName in this.files;
}

export class TSFormatter {
  private host = new MockedLanguageServiceHost;
  private languageService = ts.createLanguageService(this.host);

  format(fileName: string, text: string): string | null {
    this.host.addFile(fileName, text);

    const edits = this.languageService.getFormattingEditsForDocument(fileName, ts.getDefaultFormatCodeSettings());
    if (!edits.length) //no changes
      return null;

    edits
      .sort((a, b) => a.span.start - b.span.start)
      .reverse()
      .forEach(edit => {
        const head = text.slice(0, edit.span.start);
        const tail = text.slice(edit.span.start + edit.span.length);
        text = `${head}${edit.newText}${tail}`;
      });

    return text;
  }
}

  const formatter = new TSFormatter;
  const result = formatter.format(<path>, <data>);

passing the filename might not really be needed, or perhaps just a 'dummy.ts/tsx' so the editor knows the format? I haven't dug any deeper into this yet