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Code writer for JavaScript and TypeScript code.

Works with
This package works with Bun
This package works with Cloudflare Workers
This package works with Node.js
This package works with Deno
This package works with Browsers
JSR Score
100%
Published
2 months ago (13.0.1)

code-block-writer

npm version CI JSR stable

Code writer for JavaScript and TypeScript code.

With Deno:

deno add jsr:@david/code-block-writer

Or with Node:

npm install --save code-block-writer

Example

// import CodeBlockWriter from "code-block-writer"; // for npm
import CodeBlockWriter from "@david/code-block-writer";

const writer = new CodeBlockWriter({
  // optional options
  newLine: "\r\n",         // default: "\n"
  indentNumberOfSpaces: 2, // default: 4
  useTabs: false,          // default: false
  useSingleQuote: true     // default: false
});

writer.write("class MyClass extends OtherClass").block(() => {
  writer.writeLine(`@MyDecorator(1, 2)`);
  writer.write(`myMethod(myParam: any)`).block(() => {
    writer.write("return this.post(").quote("myArgument").write(");");
  });
});

console.log(writer.toString());

Outputs (using "\r\n" for newlines):

class MyClass extends OtherClass {
  @MyDecorator(1, 2)
  myMethod(myParam: any) {
    return this.post('myArgument');
  }
}

Methods

  • block(block?: () => void) - Indents all the code written within and surrounds it in braces.
  • inlineBlock(block?: () => void) - Same as block, but doesn't add a space before the first brace and doesn't add a newline at the end.
  • getLength() - Get the current number of characters.
  • writeLine(text: string) - Writes some text and adds a newline.
  • newLine() - Writes a newline.
  • newLineIfLastNot() - Writes a newline if what was written last wasn't a newline.
  • blankLine() - Writes a blank line. Does not allow consecutive blank lines.
  • blankLineIfLastNot() - Writes a blank line if what was written last wasn't a blank line.
  • quote() - Writes a quote character.
  • quote(text: string) - Writes text surrounded in quotes.
  • indent(times?: number) - Indents the current line. Optionally indents multiple times when providing a number.
  • indent(block?: () => void) - Indents a block of code.
  • space(times?: number) - Writes a space. Optionally writes multiple spaces when providing a number.
  • spaceIfLastNot() - Writes a space if the last was not a space.
  • tab(times?: number) - Writes a tab. Optionally writes multiple tabs when providing a number.
  • tabIfLastNot() - Writes a tab if the last was not a tab.
  • write(text: string) - Writes some text.
  • conditionalNewLine(condition: boolean) - Writes a newline if the condition is matched.
  • conditionalBlankLine(condition: boolean) - Writes a blank line if the condition is matched.
  • conditionalWrite(condition: boolean, text: string) - Writes if the condition is matched.
  • conditionalWrite(condition: boolean, textFunc: () => string) - Writes if the condition is matched.
  • conditionalWriteLine(condition: boolean, text: string) - Writes some text and adds a newline if the condition is matched.
  • conditionalWriteLine(condition: boolean, textFunc: () => string) - Writes some text and adds a newline if the condition is matched.
  • setIndentationLevel(indentationLevel: number) - Sets the current indentation level.
  • setIndentationLevel(whitespaceText: string) - Sets the current indentation level based on the provided whitespace text.
  • withIndentationLevel(indentationLevel: number, action: () => void) - Sets the indentation level within the provided action.
  • withIndentationLevel(whitespaceText: string, action: () => void) - Sets the indentation level based on the provided whitespace text within the action.
  • getIndentationLevel() - Gets the current indentation level.
  • queueIndentationLevel(indentationLevel: number) - Queues an indentation level to be used once a new line is written.
  • queueIndentationLevel(whitespaceText: string) - Queues an indentation level to be used once a new line is written based on the provided whitespace text.
  • hangingIndent(action: () => void) - Writes the code within the action with hanging indentation.
  • hangingIndentUnlessBlock(action: () => void) - Writes the code within the action with hanging indentation unless a block is written going from the first line to the second.
  • closeComment() - Writes text to exit a comment if in a comment.
  • unsafeInsert(pos: number, text: string) - Inserts text into the writer. This will not update the writer's state. Read more in its jsdoc.
  • isInComment() - Gets if the writer is currently in a comment.
  • isAtStartOfFirstLineOfBlock() - Gets if the writer is currently at the start of the first line of the text, block, or indentation block.
  • isOnFirstLineOfBlock() - Gets if the writer is currently on the first line of the text, block, or indentation block.
  • isInString() - Gets if the writer is currently in a string.
  • isLastNewLine() - Gets if the writer last wrote a newline.
  • isLastBlankLine() - Gets if the writer last wrote a blank line.
  • isLastSpace() - Gets if the writer last wrote a space.
  • isLastTab() - Gets if the writer last wrote a tab.
  • getLastChar() - Gets the last character written.
  • endsWith(text: string) - Gets if the writer ends with the provided text.
  • iterateLastChars<T>(action: (char: string, index: number) => T | undefined): T | undefined - Iterates over the writer's characters in reverse order, stopping once a non-null or undefined value is returned and returns that value.
  • iterateLastCharCodes<T>(action: (charCode: number, index: number) => T | undefined): T | undefined - A slightly faster version of iterateLastChars that doesn't allocate a string per character.
  • getOptions() - Gets the writer options.
  • toString() - Gets the string.

Other Features

  • Does not indent within strings.
  • Escapes newlines within double and single quotes created with .quote(text).

C# Version

See CodeBlockWriterSharp.

Add Package

deno add @david/code-block-writer

Import symbol

import * as mod from "@david/code-block-writer";

Add Package

npx jsr add @david/code-block-writer

Import symbol

import * as mod from "@david/code-block-writer";

Add Package

yarn dlx jsr add @david/code-block-writer

Import symbol

import * as mod from "@david/code-block-writer";

Add Package

pnpm dlx jsr add @david/code-block-writer

Import symbol

import * as mod from "@david/code-block-writer";

Add Package

bunx jsr add @david/code-block-writer

Import symbol

import * as mod from "@david/code-block-writer";