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# File System Utilities
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Core file system operations designed for Jest's testing needs, providing safe directory creation and path resolution that handle edge cases common in test environments.
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## Capabilities
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### Create Directory
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Creates directories recursively, safely ignoring errors if the directory already exists.
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```typescript { .api }
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/**
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 * Creates a directory recursively, ignoring EEXIST errors
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 * @param path - Directory path to create
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 * @throws Error if directory creation fails for reasons other than already existing
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 */
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function createDirectory(path: string): void;
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```
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**Usage Examples:**
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```typescript
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import { createDirectory } from "jest-util";
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// Create test directories safely
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createDirectory("/tmp/jest-tests/snapshots");
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createDirectory("./test-output/coverage");
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// Safe to call multiple times - won't throw if directory exists
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createDirectory("/tmp/jest-tests"); // First call creates it
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createDirectory("/tmp/jest-tests"); // Second call is safe, no error
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```
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**Error Handling:**
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- Ignores `EEXIST` errors (directory already exists) 
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- Re-throws all other errors (permission denied, invalid path, etc.)
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### Try Real Path
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Safely resolves the real path of a file or directory, falling back to the original path if resolution fails.
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```typescript { .api }
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/**
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 * Safely resolves real path, falling back to original on error
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 * @param path - Path to resolve
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 * @returns Real path if successful, or original path if resolution fails
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 */
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function tryRealpath(path: string): string;
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```
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**Usage Examples:**
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```typescript
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import { tryRealpath } from "jest-util";
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// Resolve symlinks safely
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const configPath = tryRealpath("./jest.config.js");
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const packagePath = tryRealpath("./node_modules/some-package");
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// Handles missing files gracefully
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const missingFile = tryRealpath("./non-existent.js"); 
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// Returns "./non-existent.js" instead of throwing
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// Resolves symlinks when they exist
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const symlinkPath = "/usr/bin/node"; // might be a symlink
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const realPath = tryRealpath(symlinkPath); // resolves to actual binary path
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```
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**Error Handling:**
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- Safely handles `ENOENT` errors (file not found)
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- Safely handles `EISDIR` errors (is a directory when file expected)
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- Returns original path unchanged if resolution fails
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- Does not throw exceptions for common file system edge cases