Writing this Plugin (JavaScript)

Entry Point

Plugins use StartPluginWithLambda with a single parameter — the input object:

const { StartPluginWithLambda } = require('@atomicloud/cyan-sdk');

StartPluginWithLambda(async input => {
  // Plugin logic here
  return { directory: input.directory };
});

PluginInput

// PluginInput shape:
{
  directory: string, // Absolute path to the generated output directory
  config: unknown,   // Configuration from template's cyan.yaml
}

Important: PluginInput has NO SDK file helpers. There are no readDir, readFile, or fileExists methods. Plugins use native OS operations for all file I/O.

PluginOutput

// PluginOutput shape:
{
  directory: string, // Return the directory path (typically input.directory)
}

Native File I/O Patterns

const fs = require('fs');
const path = require('path');

// Read a file
const content = fs.readFileSync(path.join(input.directory, 'src/index.js'), 'utf-8');

// Check if file exists
const exists = fs.existsSync(path.join(input.directory, 'README.md'));

// List directory
const files = fs.readdirSync(path.join(input.directory, 'src'));

// Write a file
fs.writeFileSync(path.join(input.directory, 'src/index.js'), modified);

Command Execution Patterns

const { execSync } = require('child_process');

const output = execSync('prettier --write .', {
  cwd: input.directory,
  encoding: 'utf-8',
});

File Mutation Workflow

Read files from input.directory, modify content, write back:

const fs = require('fs');
const path = require('path');

const filePath = path.join(input.directory, 'src/index.js');
const content = fs.readFileSync(filePath, 'utf-8');
const modified = content.replace(/old/g, 'new');
fs.writeFileSync(filePath, modified);

return { directory: input.directory };

Entry Point Skeleton

const { StartPluginWithLambda } = require('@atomicloud/cyan-sdk');
const fs = require('fs');
const path = require('path');

StartPluginWithLambda(async input => {
  const dir = input.directory;
  const config = input.config;

  // Use native fs operations for file I/O
  // Use child_process.execSync for command execution

  return { directory: input.directory };
});

Advanced Patterns

Walk directory recursively

const fs = require('fs');
const path = require('path');

function walkDir(dir) {
  const results = [];
  const entries = fs.readdirSync(dir, { withFileTypes: true });
  for (const entry of entries) {
    const fullPath = path.join(dir, entry.name);
    if (entry.isDirectory()) {
      results.push(...walkDir(fullPath));
    } else {
      results.push(fullPath);
    }
  }
  return results;
}

const allFiles = walkDir(input.directory);

Read, modify, and write a file

const fs = require('fs');
const path = require('path');

const content = fs.readFileSync(path.join(input.directory, 'src/index.js'), 'utf-8');
const modified = content.replace(/console\.log/g, 'logger.info');
fs.writeFileSync(path.join(input.directory, 'src/index.js'), modified);