Enforcing Clean Code: Restricting console.log While Permitting warn/error in ESLint

Preventing Debug Noise in Production

Leaving console.log statements in production code pollutes user consoles, can expose internal state, and adds unnecessary overhead. However, developers need console.warn for telemetry and console.error for genuine runtime diagnostics. The decision is to configure ESLint's no-console rule to flag console.log as an error while explicitly allowing console.warn and console.error.

Comparing Console Control Strategies

The choice of implementation depends on required complexity versus maintenance overhead. For this specific goal, the built-in ESLint rule is superior to external plugins or custom rules.

Trade-offs: Simplicity vs. Granularity

The built-in approach (Option 1) offers the best balance: it achieves strict logging control without introducing external dependencies or complex rule maintenance. While external plugins offer finer control (e.g., allowing console.table only in tests), this complexity is unnecessary when the requirement is strictly to block console.log.

Concrete Implementation in .eslintrc.json

Modify your project's ESLint configuration file (e.g., .eslintrc.json) to set no-console to "error" and define the allow array.

{
  "rules": {
    "no-console": [
      "error", 
      {
        "allow": ["warn", "error"]
      }
    ]
  }
}

Validation and Verification

To confirm the rule functions as intended, create a test file (e.g., test-console.js) containing all three calls. Run ESLint from the project root using npx eslint test-console.js.

// test-console.js
console.log("Should fail linting");
console.warn("Should pass");
console.error("Should pass");

Expected result: ESLint reports exactly one error corresponding to the console.log line. If no error is reported, check for local rule overrides in sub-directory configuration files.

Limitations

This configuration does not prevent developers from using /* eslint-disable-next-line no-console */. Mitigating this requires mandatory code review processes that scrutinize lint disable comments in production branches.