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Overview

repo2pdf integrates Prettier to automatically format code before adding it to your PDF. This ensures consistent, readable code regardless of the original formatting.
Code formatting is always enabled in repo2pdf. There’s no option to disable it - all supported files are automatically formatted.

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How It Works

The formatting process:
  1. Detects file extension (e.g., .js, .ts, .css)
  2. Maps to Prettier parser using the parser configuration
  3. Formats the code with Prettier defaults
  4. Falls back to plain text if formatting fails
  5. Continues to syntax highlighting with formatted code
From clone.ts:236-248: 
let data = await fsPromises.readFile(filePath, "utf8");
// Determine parser and format with Prettier if supported
const extension = path.extname(filePath).slice(1);
const parser = getPrettierParser(extension);

if (parser) {
  try {
    data = await prettier.format(data, { parser });
  } catch (error: unknown) {
    const errorMessage = (error as Error).message.split("\n")[0];
    console.warn(
      `Plain text fallback at ${filePath}: ${errorMessage}`,
    );
  }
}

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Supported Languages

repo2pdf maps file extensions to Prettier parsers: From clone.ts:28-56: 
function getPrettierParser(extension: string): string | null {
  const parserOptions: { [key: string]: string } = {
    js: "babel",
    jsx: "babel",
    ts: "typescript",
    tsx: "typescript",
    css: "css",
    scss: "scss",
    less: "less",
    html: "html",
    json: "json",
    md: "markdown",
    yaml: "yaml",
    graphql: "graphql",
    vue: "vue",
    angular: "angular",
    xml: "xml",
    java: "java",
    kotlin: "kotlin",
    swift: "swift",
    php: "php",
    ruby: "ruby",
    python: "python",
    perl: "perl",
    shell: "sh",
    dockerfile: "dockerfile",
    ini: "ini",
  };
  return parserOptions[extension] || null;
}

JavaScript/TypeScript

  • .js → babel
  • .jsx → babel
  • .ts → typescript
  • .tsx → typescript

Web Styles

  • .css → css
  • .scss → scss
  • .less → less

Markup

  • .html → html
  • .xml → xml
  • .vue → vue

Data Formats

  • .json → json
  • .yaml → yaml
  • .ini → ini

Backend Languages

  • .java → java
  • .kotlin → kotlin
  • .swift → swift
  • .php → php
  • .ruby → ruby
  • .python → python

Other

  • .md → markdown
  • .graphql → graphql
  • .sh → shell
  • Dockerfile → dockerfile
  • .perl → perl

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Graceful Fallback

If Prettier cannot format a file (due to syntax errors or unsupported features), repo2pdf:
  1. Logs a warning with the error message
  2. Uses the original content without formatting
  3. Continues processing normally
catch (error: unknown) {
  const errorMessage = (error as Error).message.split("\n")[0];
  console.warn(
    `Plain text fallback at ${filePath}: ${errorMessage}`,
  );
}
Files with syntax errors will not be formatted and will appear in the PDF exactly as written.

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Before and After Examples

Before formatting:
function test(){const x=1;if(x>0){return"positive";}else{return"negative";}}
After Prettier formatting:
function test() {
  const x = 1;
  if (x > 0) {
    return "positive";
  } else {
    return "negative";
  }
}
Before formatting:
type User={name:string,age:number};const users:User[]=[{name:"Alice",age:30},{name:"Bob",age:25}];
After Prettier formatting:
type User = { name: string; age: number };
const users: User[] = [
  { name: "Alice", age: 30 },
  { name: "Bob", age: 25 },
];
Before formatting:
{"name":"repo2pdf","version":"1.0.0","dependencies":{"prettier":"^3.0.0"}}
After Prettier formatting:
{
  "name": "repo2pdf",
  "version": "1.0.0",
  "dependencies": {
    "prettier": "^3.0.0"
  }
}
Before formatting:
.container{display:flex;justify-content:center;align-items:center;background-color:#fff;}
After Prettier formatting:
.container {
  display: flex;
  justify-content: center;
  align-items: center;
  background-color: #fff;
}

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Prettier Configuration

repo2pdf uses Prettier’s default settings with only the parser specified: 
data = await prettier.format(data, { parser });
This means:
  • Print Width: 80 characters
  • Tab Width: 2 spaces
  • Semicolons: Enabled
  • Single Quotes: False (uses double quotes)
  • Trailing Commas: “all” (in ES5)
If you want different formatting in your PDF, format your files before running repo2pdf.

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Processing Order

The complete processing pipeline: From clone.ts:234-278:
  1. Read file content
  2. Format with Prettier (if parser available)
  3. Replace tabs with 4 spaces
  4. Normalize line endings
  5. Remove comments (if enabled)
  6. Remove empty lines (if enabled)
  7. Apply syntax highlighting
  8. Add to PDF

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Unsupported File Types

If no parser is found, the file is processed without formatting: 
return parserOptions[extension] || null;
Examples of unsupported extensions:
  • .go (Go)
  • .rs (Rust)
  • .c, .cpp (C/C++)
  • .lua (Lua)
  • .r (R)
Unsupported files are still included in the PDF - they just aren’t formatted by Prettier.

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Tab Replacement

After formatting, tabs are replaced with spaces: 
data = data.replace(/\t/g, "    "); // 4 spaces
This ensures consistent indentation in the monospace PDF font.

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Line Ending Normalization

All line endings are normalized to Unix-style (\n): 
data = data.replace(/\r\n/g, "\n").replace(/\r/g, "\n");
This prevents issues with:
  • Windows line endings (\r\n)
  • Old Mac line endings (\r)

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Benefits of Auto-Formatting

Consistency

All code follows the same style, regardless of author preferences

Readability

Properly indented and spaced code is easier to read

Professional

PDFs look polished and well-maintained

Reduced Size

Consistent formatting can reduce PDF file size

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Interaction with Other Features

Line numbers are added after formatting:
// Unformatted: function test(){return true;}

// PDF output:
1 function test() {
2   return true;
3 }
Line numbers reflect the formatted code, not the original.
Syntax highlighting is applied after formatting:
  1. Format with Prettier → clean structure
  2. Highlight with highlight.js → add colors
This ensures the cleanest, most readable output.
If you enable comment removal, comments are removed after formatting:
// 1. Format
function test() {
  // Comment
  return true;
}

// 2. Remove comments
function test() {
  return true;
}

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Error Handling

When Prettier fails: 
Plain text fallback at src/broken.js: Unexpected token (1:5)
The file is still processed, just without formatting.
Check the console output for any formatting warnings to identify files with syntax errors.

Syntax Highlighting

Add colors after formatting for maximum readability

Line Numbers

Line numbers match the formatted output