File Conversion

/**
 * Converts JavaScript files to TypeScript during project generation
 * Handles file renaming and content preservation with configurable strategies
 * @param api - Generator API instance providing file manipulation methods
 * @param options - Conversion configuration options
 */
function convert(api, options: ConvertOptions = {}): void;

interface ConvertOptions {
  convertJsToTs?: boolean;     // Convert all .js files to .ts (default: true)
}

// Used internally by the generator module
const convert = require('@vue/cli-plugin-typescript/generator/convert');

// Applied during project generation
convert(api, { convertJsToTs: true });

/**
 * File processing logic applied after template rendering
 * Uses api.postProcessFiles to modify generated file structure
 * @param files - File object containing generated files
 */
api.postProcessFiles((files) => {
  // Conversion logic applied here
});

/**
 * Full conversion mode configuration
 * Converts all .js files to .ts except excluded patterns
 */
const fullConversionConfig = {
  jsRE: /\.js$/,                              // Matches .js files
  excludeRE: /^tests\/e2e\/|(\.config|rc)\.js$/, // Default exclusions
  
  // Modified exclusions when e2e-webdriverio plugin is present
  webdriverioExcludeRE: /(\.config|rc)\.js$/
};

/**
 * Selective conversion mode configuration
 * Only converts the main application entry file to TypeScript
 */
const selectiveConversionConfig = {
  entryFile: api.entryFile,        // Main entry file (usually src/main.js)
  targetFile: string               // Converted .ts version of entry file
};

/**
 * File exclusion pattern configuration
 * Defines which files should not be converted to TypeScript
 */
const exclusionPatterns = {
  // Default exclusions
  default: /^tests\/e2e\/|(\.config|rc)\.js$/,
  
  // WebDriverIO specific exclusions (less restrictive)
  webdriverio: /(\.config|rc)\.js$/
};

/**
 * File content preservation during conversion
 * Ensures no content is lost during .js to .ts conversion
 */
const contentPreservation = {
  sourceContent: files[jsFile],     // Original JavaScript content
  targetContent: files[tsFile],     // Existing TypeScript content (if any)
  
  // Priority: existing .ts file > converted .js file content
  finalContent: files[tsFile] || files[jsFile]
};

/**
 * Plugin integration affecting file conversion behavior
 * Different exclusion patterns based on installed plugins
 */
if (api.hasPlugin('e2e-webdriverio')) {
  // Use less restrictive exclusion pattern
  // Allows WebDriverIO test files to be converted to TypeScript
  excludeRE = /(\.config|rc)\.js$/;
} else {
  // Use default exclusion pattern  
  // Excludes all e2e test files from conversion
  excludeRE = /^tests\/e2e\/|(\.config|rc)\.js$/;
}

// Before conversion (project files)
files = {
  'src/main.js': 'import Vue from "vue"...',
  'src/components/HelloWorld.js': 'export default {...}',
  'vue.config.js': 'module.exports = {...}',
  'tests/e2e/specs/test.js': 'describe(...)'
};

// After conversion (convertJsToTs: true)
files = {
  'src/main.ts': 'import Vue from "vue"...',
  'src/components/HelloWorld.ts': 'export default {...}',
  'vue.config.js': 'module.exports = {...}', // Excluded
  'tests/e2e/specs/test.js': 'describe(...)'  // Excluded
};

// Before conversion (project files)
files = {
  'src/main.js': 'import Vue from "vue"...',
  'src/components/HelloWorld.js': 'export default {...}',
  'src/utils/helpers.js': 'export function helper() {...}'
};

// After conversion (convertJsToTs: false)
files = {
  'src/main.ts': 'import Vue from "vue"...',           // Converted
  'src/components/HelloWorld.js': 'export default {...}', // Unchanged
  'src/utils/helpers.js': 'export function helper() {...}' // Unchanged
};

// When both .js and .ts files exist
files = {
  'src/component.js': '// JavaScript version',
  'src/component.ts': '// TypeScript version (existing)'
};

// Result: TypeScript version is preserved
files = {
  'src/component.ts': '// TypeScript version (existing)'
  // JavaScript version is removed
};