Detect Conflict

Common errors

• Error: ENOTDIR: not a directory, open 'your-directory/file.js'

  cause The `filepath` provided to `conflict` function resolves to a directory, but an attempt was made to open it as a file by underlying `fs` operations.
  fix The library explicitly states that if `filepath` is a directory, it returns `true`. This error likely comes from *your* code trying to interact with the path as a file. Ensure `filepath` points to an actual file before passing it to `detect-conflict`, or handle the `true` return specifically for directories.

• TypeError: conflict is not a function

  cause This usually indicates an incorrect import statement or an attempt to call a non-existent function from the module.
  fix Ensure you are importing the `conflict` function correctly. For CommonJS, use `const conflict = require('detect-conflict');`. For ESM, use `import conflict from 'detect-conflict';`.

Warnings

• gotcha If the `filepath` argument points to a directory instead of a file, the `conflict` function will always return `true`.
  Fix: Ensure that `filepath` always resolves to an actual file. Use `fs.statSync(filepath).isFile()` to verify before calling `conflict` if directory handling is uncertain.
• gotcha When passing file `contents` as a string, `detect-conflict` assumes it is UTF-8 encoded. For other encodings, or for binary content, a `Buffer` must be passed.
  Fix: For non-UTF8 text files or binary files, read the file content into a Node.js `Buffer` using `fs.readFileSync(filepath)` (without specifying encoding) and pass the `Buffer` directly to the `conflict` function.
• breaking Versions prior to 1.0.1 had a bug where passing `null` as the `contents` argument could lead to unexpected behavior or errors.
  Fix: Upgrade to `detect-conflict@1.0.1` or newer. Alternatively, ensure that the `contents` argument is always a `String` or `Buffer` and never `null`.

Install

• npm install detect-conflict npm
• yarn add detect-conflict yarn
• pnpm add detect-conflict pnpm

Imports

• conflict
  wrong:

  import { conflict } from 'detect-conflict';

  correct:

  import conflict from 'detect-conflict';

  The primary `conflict` function is likely the default export in ESM environments.
• conflict

  const conflict = require('detect-conflict');

  CommonJS usage is demonstrated directly in the package's README.
• Type declarations

  /// <reference types="detect-conflict" />

  While explicit type imports aren't typically needed for single-function libraries, this indicates how TypeScript would infer types if the library ships them.

Quickstart

This example demonstrates how to use `detect-conflict` to check if new content for a file will conflict with the content currently on disk, showing both a conflicting and non-conflicting scenario.

import conflict from 'detect-conflict';
import fs from 'fs';
import path from 'path';

const filePath = path.join(process.cwd(), 'example-file.js');
const existingContent = 'console.log("Hello world!");\nconst foo = 1;';
const newContent = 'console.log("Greetings!");\nconst foo = 2;'; // This will conflict on 'foo'
const safeContent = 'console.log("New message!");\nconst bar = 3;'; // This should not conflict

// Ensure the file exists for demonstration
fs.writeFileSync(filePath, existingContent, 'utf8');

console.log(`Checking for conflict in ${filePath}`);

const isConflicting = conflict(filePath, newContent);
console.log(`New content conflicts with existing: ${isConflicting}`);

const isConflictingSafe = conflict(filePath, safeContent);
console.log(`Safe content conflicts with existing: ${isConflictingSafe}`);

// Clean up the created file
fs.unlinkSync(filePath);