# Code Smell 278 - DirName and File > TL;DR: Use clear names for better code understanding. # Problems - Unclear variable purpose - [Bijection](https://maximilianocontieri.com/the-one-and-only-software-design-principle) Fault - Misleading context - Repetitive code - Harder maintenance - Reduced readability - [Abbreviations](https://maximilianocontieri.com/code-smell-33-abbreviations) - Increased cognitive load # Solutions 1. Honor the [Bijection](https://maximilianocontieri.com/the-one-and-only-software-design-principle) 2. Use precise names 3. Avoid ambiguity 4. Keep context clear 5. Extract reusable code 6. Follow naming conventions 7. Reify names with their rules # Context When handling a single *fileName* or *directoryPath*, vague names like *file* or *dirName* create confusion. * A *file* should represent a File * A *fileName* should represent the name of a file * *fileContents* should represent the content of a file * A *fileHandler* should represent a pointer to an external resource * *dirName* should be *directoryPath* Clear names like *fileName* for names and *directoryPath* for directories communicate each variable’s role. When you name a variable file, it can confuse others about its purpose. Does it store a file object or just the filename? When you name a variable *dirName* instead of directoryName it leads to ambiguity. Clear and descriptive variable names improve code readability and maintainability, especially in collaborative environments. # Sample Code ## Wrong [Gist Url]: # (https://gist.github.com/mcsee/0fb80439dd8c8e83797a3dad15a0cb22) ```javascript function importBoardGameScores(file) { if (file) { const data = fs.readFileSync(file, 'utf-8'); // Process board game scores... } } function importDirectoryScores(dirName) { // 'dir' is an abbreviation const files = fs.readdirSync(dirName); files.forEach(file => { const data = fs.readFileSync(`${dirName}/${file}`, 'utf-8'); // Process each file's board game scores... }); } } ``` ## Right [Gist Url]: # (https://gist.github.com/mcsee/2946663ac7d99b4925457dbbe5dfaefd) ```javascript function importBoardGameScores(fileName) { if (fileName) { const data = fs.readFileSync(fileName, 'utf-8'); // Process board game scores... } } function importDirectoryBoardGamesScores(directoryPath) { const fileNames = fs.readdirSync(directoryPath); // Note the variable holding filenames // and not files fileNames.forEach(filename => { const fullPath = path.join(directoryPath, filename); const scores = importBoardGameScores(fullPath); allScores.push(scores); }); return allScores.flat(); // You can also reify the concept of a filename // And avoid repeating the rules everywhere class Filename { value; constructor(value) { this.validateFilename(value); this.value = value; } validateFilename(value) { const invalidCharacters = /[<>:"/\\|?*\x00-\x1F]/g; if (invalidCharacters.test(value)) { throw new Error ('Filename contains invalid characters'); } if (/^[. ]+$/.test(value)) { throw new Error ('Filename cannot consist only of dots or spaces'); } if (value.length > 255) { throw new Error ('Filename is too long'); } } toString() { return this.value; } get value() { return this.value; } } ``` # Detection [X] Semi-Automatic Look for generic names in code handling files or directory paths like *file* or *dirName*. # Tags - Naming # Level [x] Beginner # AI Generation AI models may default to ambiguous names like *file* or *dirName* without specific instructions. Adding descriptive naming and code extraction guidelines can improve the AI's output. # AI Detection AI tools can fix this smell by using clear naming conventions and suggesting code extraction if prompted to avoid redundant code. ## Try Them! *Remember: AI Assistants make lots of mistakes* | Without Proper Instructions | With Specific Instructions | | -------- | ------- | | [ChatGPT](https://chat.openai.com/?q=Correct+and+explain+this+code%3A+%60%60%60javascript%0D%0Afunction+importBoardGameScores%28file%29+%7B%0D%0A++if+%28file%29+%7B%0D%0A++++const+data+%3D+fs.readFileSync%28file%2C+%27utf-8%27%29%3B%0D%0A++++%2F%2F+Process+board+game+scores...%0D%0A++%7D%0D%0A%7D%0D%0A%0D%0Afunction+importDirectoryScores%28dirName%29+%7B%0D%0A++%2F%2F+%27dir%27+is+an+abbreviation%0D%0A++const+files+%3D+fs.readdirSync%28dirName%29%3B%0D%0A++files.forEach%28file+%3D%3E+%7B%0D%0A++++const+data+%3D+fs.readFileSync%28%60%24%7BdirName%7D%2F%24%7Bfile%7D%60%2C+%27utf-8%27%29%3B%0D%0A++++%2F%2F+Process+each+file%27s+board+game+scores...%0D%0A++%7D%29%3B%0D%0A++%7D%0D%0A%7D%0D%0A%60%60%60) | [ChatGPT](https://chat.openai.com/?q=replace+file+to+filename+and+reify+the+Name+as+a+standalone+class%2C+rename+dirName+to+directoryPath%3A+%60%60%60javascript%0D%0Afunction+importBoardGameScores%28file%29+%7B%0D%0A++if+%28file%29+%7B%0D%0A++++const+data+%3D+fs.readFileSync%28file%2C+%27utf-8%27%29%3B%0D%0A++++%2F%2F+Process+board+game+scores...%0D%0A++%7D%0D%0A%7D%0D%0A%0D%0Afunction+importDirectoryScores%28dirName%29+%7B%0D%0A++%2F%2F+%27dir%27+is+an+abbreviation%0D%0A++const+files+%3D+fs.readdirSync%28dirName%29%3B%0D%0A++files.forEach%28file+%3D%3E+%7B%0D%0A++++const+data+%3D+fs.readFileSync%28%60%24%7BdirName%7D%2F%24%7Bfile%7D%60%2C+%27utf-8%27%29%3B%0D%0A++++%2F%2F+Process+each+file%27s+board+game+scores...%0D%0A++%7D%29%3B%0D%0A++%7D%0D%0A%7D%0D%0A%60%60%60) | | [Claude](https://claude.ai/new?q=Correct+and+explain+this+code%3A+%60%60%60javascript%0D%0Afunction+importBoardGameScores%28file%29+%7B%0D%0A++if+%28file%29+%7B%0D%0A++++const+data+%3D+fs.readFileSync%28file%2C+%27utf-8%27%29%3B%0D%0A++++%2F%2F+Process+board+game+scores...%0D%0A++%7D%0D%0A%7D%0D%0A%0D%0Afunction+importDirectoryScores%28dirName%29+%7B%0D%0A++%2F%2F+%27dir%27+is+an+abbreviation%0D%0A++const+files+%3D+fs.readdirSync%28dirName%29%3B%0D%0A++files.forEach%28file+%3D%3E+%7B%0D%0A++++const+data+%3D+fs.readFileSync%28%60%24%7BdirName%7D%2F%24%7Bfile%7D%60%2C+%27utf-8%27%29%3B%0D%0A++++%2F%2F+Process+each+file%27s+board+game+scores...%0D%0A++%7D%29%3B%0D%0A++%7D%0D%0A%7D%0D%0A%60%60%60) | [Claude](https://claude.ai/new?q=replace+file+to+filename+and+reify+the+Name+as+a+standalone+class%2C+rename+dirName+to+directoryPath%3A+%60%60%60javascript%0D%0Afunction+importBoardGameScores%28file%29+%7B%0D%0A++if+%28file%29+%7B%0D%0A++++const+data+%3D+fs.readFileSync%28file%2C+%27utf-8%27%29%3B%0D%0A++++%2F%2F+Process+board+game+scores...%0D%0A++%7D%0D%0A%7D%0D%0A%0D%0Afunction+importDirectoryScores%28dirName%29+%7B%0D%0A++%2F%2F+%27dir%27+is+an+abbreviation%0D%0A++const+files+%3D+fs.readdirSync%28dirName%29%3B%0D%0A++files.forEach%28file+%3D%3E+%7B%0D%0A++++const+data+%3D+fs.readFileSync%28%60%24%7BdirName%7D%2F%24%7Bfile%7D%60%2C+%27utf-8%27%29%3B%0D%0A++++%2F%2F+Process+each+file%27s+board+game+scores...%0D%0A++%7D%29%3B%0D%0A++%7D%0D%0A%7D%0D%0A%60%60%60) | | [Perplexity](https://perplexity.ai/?q=Correct+and+explain+this+code%3A+%60%60%60javascript%0D%0Afunction+importBoardGameScores%28file%29+%7B%0D%0A++if+%28file%29+%7B%0D%0A++++const+data+%3D+fs.readFileSync%28file%2C+%27utf-8%27%29%3B%0D%0A++++%2F%2F+Process+board+game+scores...%0D%0A++%7D%0D%0A%7D%0D%0A%0D%0Afunction+importDirectoryScores%28dirName%29+%7B%0D%0A++%2F%2F+%27dir%27+is+an+abbreviation%0D%0A++const+files+%3D+fs.readdirSync%28dirName%29%3B%0D%0A++files.forEach%28file+%3D%3E+%7B%0D%0A++++const+data+%3D+fs.readFileSync%28%60%24%7BdirName%7D%2F%24%7Bfile%7D%60%2C+%27utf-8%27%29%3B%0D%0A++++%2F%2F+Process+each+file%27s+board+game+scores...%0D%0A++%7D%29%3B%0D%0A++%7D%0D%0A%7D%0D%0A%60%60%60) | [Perplexity](https://perplexity.ai/?q=replace+file+to+filename+and+reify+the+Name+as+a+standalone+class%2C+rename+dirName+to+directoryPath%3A+%60%60%60javascript%0D%0Afunction+importBoardGameScores%28file%29+%7B%0D%0A++if+%28file%29+%7B%0D%0A++++const+data+%3D+fs.readFileSync%28file%2C+%27utf-8%27%29%3B%0D%0A++++%2F%2F+Process+board+game+scores...%0D%0A++%7D%0D%0A%7D%0D%0A%0D%0Afunction+importDirectoryScores%28dirName%29+%7B%0D%0A++%2F%2F+%27dir%27+is+an+abbreviation%0D%0A++const+files+%3D+fs.readdirSync%28dirName%29%3B%0D%0A++files.forEach%28file+%3D%3E+%7B%0D%0A++++const+data+%3D+fs.readFileSync%28%60%24%7BdirName%7D%2F%24%7Bfile%7D%60%2C+%27utf-8%27%29%3B%0D%0A++++%2F%2F+Process+each+file%27s+board+game+scores...%0D%0A++%7D%29%3B%0D%0A++%7D%0D%0A%7D%0D%0A%60%60%60) | | [Copilot](https://www.bing.com/chat?showconv=1&sendquery=1&q=Correct+and+explain+this+code%3A+%60%60%60javascript%0D%0Afunction+importBoardGameScores%28file%29+%7B%0D%0A++if+%28file%29+%7B%0D%0A++++const+data+%3D+fs.readFileSync%28file%2C+%27utf-8%27%29%3B%0D%0A++++%2F%2F+Process+board+game+scores...%0D%0A++%7D%0D%0A%7D%0D%0A%0D%0Afunction+importDirectoryScores%28dirName%29+%7B%0D%0A++%2F%2F+%27dir%27+is+an+abbreviation%0D%0A++const+files+%3D+fs.readdirSync%28dirName%29%3B%0D%0A++files.forEach%28file+%3D%3E+%7B%0D%0A++++const+data+%3D+fs.readFileSync%28%60%24%7BdirName%7D%2F%24%7Bfile%7D%60%2C+%27utf-8%27%29%3B%0D%0A++++%2F%2F+Process+each+file%27s+board+game+scores...%0D%0A++%7D%29%3B%0D%0A++%7D%0D%0A%7D%0D%0A%60%60%60) | [Copilot](https://www.bing.com/chat?showconv=1&sendquery=1&q=replace+file+to+filename+and+reify+the+Name+as+a+standalone+class%2C+rename+dirName+to+directoryPath%3A+%60%60%60javascript%0D%0Afunction+importBoardGameScores%28file%29+%7B%0D%0A++if+%28file%29+%7B%0D%0A++++const+data+%3D+fs.readFileSync%28file%2C+%27utf-8%27%29%3B%0D%0A++++%2F%2F+Process+board+game+scores...%0D%0A++%7D%0D%0A%7D%0D%0A%0D%0Afunction+importDirectoryScores%28dirName%29+%7B%0D%0A++%2F%2F+%27dir%27+is+an+abbreviation%0D%0A++const+files+%3D+fs.readdirSync%28dirName%29%3B%0D%0A++files.forEach%28file+%3D%3E+%7B%0D%0A++++const+data+%3D+fs.readFileSync%28%60%24%7BdirName%7D%2F%24%7Bfile%7D%60%2C+%27utf-8%27%29%3B%0D%0A++++%2F%2F+Process+each+file%27s+board+game+scores...%0D%0A++%7D%29%3B%0D%0A++%7D%0D%0A%7D%0D%0A%60%60%60) | | [Gemini](https://gemini.google.com/?q=Correct+and+explain+this+code%3A+%60%60%60javascript%0D%0Afunction+importBoardGameScores%28file%29+%7B%0D%0A++if+%28file%29+%7B%0D%0A++++const+data+%3D+fs.readFileSync%28file%2C+%27utf-8%27%29%3B%0D%0A++++%2F%2F+Process+board+game+scores...%0D%0A++%7D%0D%0A%7D%0D%0A%0D%0Afunction+importDirectoryScores%28dirName%29+%7B%0D%0A++%2F%2F+%27dir%27+is+an+abbreviation%0D%0A++const+files+%3D+fs.readdirSync%28dirName%29%3B%0D%0A++files.forEach%28file+%3D%3E+%7B%0D%0A++++const+data+%3D+fs.readFileSync%28%60%24%7BdirName%7D%2F%24%7Bfile%7D%60%2C+%27utf-8%27%29%3B%0D%0A++++%2F%2F+Process+each+file%27s+board+game+scores...%0D%0A++%7D%29%3B%0D%0A++%7D%0D%0A%7D%0D%0A%60%60%60) | [Gemini](https://gemini.google.com/?q=replace+file+to+filename+and+reify+the+Name+as+a+standalone+class%2C+rename+dirName+to+directoryPath%3A+%60%60%60javascript%0D%0Afunction+importBoardGameScores%28file%29+%7B%0D%0A++if+%28file%29+%7B%0D%0A++++const+data+%3D+fs.readFileSync%28file%2C+%27utf-8%27%29%3B%0D%0A++++%2F%2F+Process+board+game+scores...%0D%0A++%7D%0D%0A%7D%0D%0A%0D%0Afunction+importDirectoryScores%28dirName%29+%7B%0D%0A++%2F%2F+%27dir%27+is+an+abbreviation%0D%0A++const+files+%3D+fs.readdirSync%28dirName%29%3B%0D%0A++files.forEach%28file+%3D%3E+%7B%0D%0A++++const+data+%3D+fs.readFileSync%28%60%24%7BdirName%7D%2F%24%7Bfile%7D%60%2C+%27utf-8%27%29%3B%0D%0A++++%2F%2F+Process+each+file%27s+board+game+scores...%0D%0A++%7D%29%3B%0D%0A++%7D%0D%0A%7D%0D%0A%60%60%60) | # Conclusion By using precise names like *fileName* and *directoryPath* and extracting reusable methods, you improve code clarity and maintainability. These simple practices help reduce redundancy and keep your code understandable. # Relations %[https://maximilianocontieri.com/code-smell-33-abbreviations] # Disclaimer Code Smells are my [opinion](https://maximilianocontieri.com/i-wrote-more-than-90-articles-on-2021-here-is-what-i-learned). # Credits Photo by [Gabriel Heinzer](https://unsplash.com/@6heinz3r) on [Unsplash](https://unsplash.com/photos/a-close-up-of-a-computer-screen-with-a-bunch-of-words-on-it-EUzk9BIEq6M) * * * > Code should be written to be read by humans first, and machines second. _Don Laabs_ %[https://maximilianocontieri.com/software-engineering-great-quotes] * * * This article is part of the CodeSmell Series. %[https://maximilianocontieri.com/how-to-find-the-stinky-parts-of-your-code]