Briklab Docs

Warner Examples ​

Real-world examples and common patterns for using Warner in your applications.

Build System Warnings ​

Track warnings during a build process:

ts
import { Warner } from "@briklab/lib/warner";

class BuildSystem {
  private warner: Warner;

  constructor() {
    this.warner = new Warner({
      level: "summary",
      packageName: "BuildSystem"
    });
  }

  compile(files: string[]): void {
    files.forEach(file => {
      if (file.includes("deprecated")) {
        this.warner.warn({
          message: `Deprecated syntax in ${file}`,
          source: "compiler",
          hint: "Update to modern syntax"
        });
      }
    });
  }

  reportResults(): void {
    this.warner.finalize();
  }
}

const build = new BuildSystem();
build.compile(["utils.ts", "deprecated-lib.ts"]);
build.reportResults();

Data Migration Warnings ​

Monitor warnings during data processing:

ts
import { Warner } from "@briklab/lib/warner";

const warner = new Warner({
  level: "full",
  packageName: "DataMigration"
});

const records = [
  { id: 1, name: "Alice" },
  { id: 2 }, // Missing name
  { id: 3, name: "Charlie" }
];

records.forEach((record, i) => {
  if (!record.name) {
    warner.warn({
      message: `Record ${i} missing required field: name`,
      source: "migration",
      level: "warn",
      hint: `Set default name or skip record`
    });
  }
});

warner.finalize();

API Client Warnings ​

Track API deprecations and issues:

ts
import { Warner } from "@briklab/lib/warner";

class ApiClient {
  private warner: Warner;

  constructor() {
    this.warner = new Warner({
      level: "summary",
      packageName: "ApiClient"
    });
  }

  callEndpoint(endpoint: string, version: number): void {
    if (version < 3) {
      this.warner.warn({
        message: `Using deprecated API version ${version}`,
        source: endpoint,
        hint: `Upgrade to API v3 or higher`
      });
    }
  }

  report(): void {
    this.warner.finalize();
  }
}

const client = new ApiClient();
client.callEndpoint("/users", 1);
client.callEndpoint("/posts", 2);
client.report();

Live Demo - Real-world Warnings ​

Console
No logs yet.

Configuration Validation with Warnings ​

Warn on suboptimal configuration:

ts
import { Warner } from "@briklab/lib/warner";

interface AppConfig {
  debug: boolean;
  logLevel: string;
  cacheSize: number;
  timeoutMs: number;
}

function validateConfig(config: AppConfig): void {
  const warner = new Warner({
    level: "full",
    packageName: "ConfigValidator"
  });

  if (config.debug && config.logLevel !== "debug") {
    warner.warn({
      message: "Debug enabled but log level not set to debug",
      hint: "Set logLevel: 'debug' for better debugging"
    });
  }

  if (config.cacheSize > 1000) {
    warner.warn({
      message: "Cache size is very large",
      hint: "Consider reducing for lower memory usage"
    });
  }

  if (config.timeoutMs < 100) {
    warner.warn({
      message: "Timeout is very short",
      hint: "May cause premature connection drops"
    });
  }

  warner.finalize();
}

const config: AppConfig = {
  debug: true,
  logLevel: "info",
  cacheSize: 2000,
  timeoutMs: 50
};

validateConfig(config);

Testing with Warner ​

Use Warner in test assertions:

ts
import { Warner } from "@briklab/lib/warner";

class TestRunner {
  warnings: number = 0;

  runTests(): void {
    const warner = new Warner({
      level: "silent"
    });

    // Run tests...
    warner.warn({ message: "Test suite warning 1" });
    warner.warn({ message: "Test suite warning 2" });

    this.warnings = 2; // Track count
  }

  assert(): void {
    if (this.warnings > 0) {
      console.log(`Tests passed with ${this.warnings} warnings`);
    }
  }
}

const runner = new TestRunner();
runner.runTests();
runner.assert();

Next Steps ​