SmartLogMacro

✨ Swift macros for easier logging via Apple's unified logging system with optional 3rd-party logging support (e.g. Crashlytics)

#log(logger, .info, "User \(userId) signed out at \(Date())", privacy: .public, customLoggingFunction: YourLogger.log)

Expands to:

_ = (logger.log(level: .info, "User \(userId, privacy: .public) signed out at \(Date(), privacy: .public)"), YourLogger.log("[logger] Info: User \(userId) signed out at \(Date())"))

In addition, there are several shorthand macros available:

Macro	Privacy Level	External Logging	Description
#log	configurable	optional	Full control over logging behaviour
#logPublic	.public	optional	Shortcut for always-public logs
#smartLog	configurable	always enabled	Forwards to SmartLogMacroCustomLogger.log
#smartLogPublic	.public	always enabled	Simplest usage — public logs + external forwarding

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✅ Key benefits

• 🔒 Privacy made easy — apply a single privacy setting to all interpolated values
• 📤 Optional external logging — forward the log message to any function (e.g. Crashlytics.crashlytics().log)
• 🏷️ Automatic formatting — external logs include logger category and severity level
• ⚡ Zero runtime overhead — macro expands at compile-time

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📦 Installation

SmartLogMacro is available via Swift Package Manager.

To add it to your project in Xcode:

1. Open your project.
2. Go to File → Add Packages...
3. Enter the URL: https://github.com/andriyGo/SmartLogMacro
4. Select the version you want to use and press Add Package.

Or, add it manually to your Package.swift:

dependencies: [
    .package(url: "https://github.com/andriyGo/SmartLogMacro", from: "1.0.0")
]

Then add SmartLogMacro to your target dependencies:

.target(
    name: "MyTarget",
    dependencies: [.product(name: "SmartLogMacro", package: "SmartLogMacro")]
)

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🚀 Usage

🔒 One-line privacy control for multiple values

With Apple's Logger:

logger.info("Item \(item, privacy: .public) at \(indexPath, privacy: .public)")

With SmartLogMacro:

#log(logger, .info, "Item \(item) at \(indexPath)", privacy: .public)

Expands to:

logger.log(level: .info, "Item \(item, privacy: .public) at \(indexPath, privacy: .public)")

Or even shorter:

#logPublic(logger, .info, "Item \(item) at \(indexPath)")

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📤 Send logs to 3rd-party systems (like Crashlytics)

External logs are automatically formatted with [category] Level: message for better readability and filtering.

Using #smartLog or #smartLogPublic

#smartLog(.auth, .error, "Sign-out failed for user: \(userId)")
#smartLogPublic(.network, .info, "Request completed in \(duration)ms")

External logs will appear as:

[auth] Error: Sign-out failed for user: 12345
[network] Info: Request completed in 234ms

To enable this, define:

struct SmartLogMacroCustomLogger {
    static func log(_ message: String) {
        Crashlytics.crashlytics().log(message)
    }
}

Or use:

typealias SmartLogMacroCustomLogger = MyLogger

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Fine-grained control

#log(.database, .error, "Query failed: \(error)", customLoggingFunction: Crashlytics.crashlytics().log)
#logPublic(.api, .debug, "Response received", customLoggingFunction: MyLogger.send)

External logs will be formatted as:

[database] Error: Query failed: timeout
[api] Debug: Response received

Define your own custom logger:

struct CustomLogger {
    static func log(_ message: String) {
        Crashlytics.crashlytics().log(message)
        Analytics.logEvent("log", parameters: ["message": message])
    }
}

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🏷️ Logger Category Extraction

SmartLogMacro automatically extracts the logger category for external logging:

// Using shorthand syntax (.network)
#smartLogPublic(.network, .info, "Request sent")
// External log: "[network] Info: Request sent"

// Using full syntax (Logger.auth)
#smartLogPublic(Logger.auth, .error, "Login failed")
// External log: "[auth] Error: Login failed"

// Using variable names
let apiLogger = Logger(...)
#smartLogPublic(apiLogger, .debug, "Testing")
// External log: "[apiLogger] Debug: Testing"

The category and log level are extracted at compile-time with zero runtime overhead.

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⚠️ Limitations

1. No trailing closure support for customLoggingFunction
2. Expanded macro expands to a single-line tuple expression
   This avoids introducing extra lines, but the expression result is discarded with _ = (...).
3. Category extraction requires consistent naming
   Use .categoryName or Logger.categoryName syntax for best results.

💬 Most of these limitations stem from the desire to keep SmartLogMacro lightweight and simple until community feedback arrives.

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🤝 Contributions

Contributions are welcome!
Open an issue or pull request — all feedback is appreciated.

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☕️ Support

Enjoying SmartLogMacro?
Buy me a coffee ☕💙

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📄 License

SmartLogMacro is available under the Apache License 2.0.
See the LICENSE file for full details.