Simple Inspector: A Free Code Review Tool for Developers

What Simple Inspector Does

Simple Inspector is a lightweight code review and static analysis tool designed to catch common errors and style issues in your code before they reach production. It scans your files for bugs, security vulnerabilities, and formatting problems, then reports them in a format you can act on immediately. Unlike heavy enterprise tools, Simple Inspector runs locally on your machine and integrates into your existing workflow without requiring complex setup or licensing agreements.

The tool works by analyzing your code against a set of predefined rules—things like unused variables, missing error handling, inconsistent naming conventions, and potential null pointer exceptions. When it finds an issue, it tells you exactly where it is, why it matters, and often suggests how to fix it. You can run it on demand, schedule it to run automatically, or integrate it into your build pipeline so every commit gets checked.

Key Takeaways

• Simple Inspector scans code for bugs, security issues, and style problems without requiring installation of heavy dependencies or paid licenses.
• The tool runs locally on your machine and can be integrated into your build process or version control workflow.
• Reports show the exact line number, the problem found, and often a suggested fix you can implement immediately.
• Configuration files let you customize which rules apply to your project, so you can enforce your team's coding standards.
• Simple Inspector supports multiple programming languages, though coverage varies by language and rule type.

How to Install and Run Simple Inspector

Installation depends on your operating system and development environment. Most developers install Simple Inspector through a package manager—npm for Node.js projects, pip for Python, or your language's native package system. Once installed, you run it from the command line by pointing it at a file or folder: simple-inspector ./src will scan everything in your src directory and print results to the terminal.

The first run takes a few seconds longer because the tool indexes your project. Subsequent runs are faster. You can also set it to watch mode, where it rescans files automatically whenever you save changes—useful during active development when you want immediate feedback. Most teams add a Simple Inspector check to their continuous integration pipeline so every pull request gets scanned before merge.

Understanding the Report Output

When Simple Inspector finds an issue, it reports the file name, line number, the rule that triggered, and a description of the problem. For example: src/auth.js:42 — Missing error handler in async function. This tells you exactly where to look and what to fix. Severity levels (error, warning, info) help you prioritize: errors block deployment in strict mode, warnings flag risky patterns, and info messages suggest improvements.

You can filter reports by severity, rule type, or file pattern. This is useful when you inherit a large codebase with thousands of existing issues—you can focus on new problems first, then gradually address the backlog. Export options let you save reports as JSON or CSV for tracking over time or sharing with your team.

Configuring Rules for Your Project

Simple Inspector comes with sensible defaults, but every team has different standards. Configuration happens through a .simple-inspector.json file in your project root. In this file, you enable or disable specific rules, set severity levels, and define exceptions. For example, you might disable a rule about line length if your team prefers longer, more readable lines, or you might mark a particular rule as an error instead of a warning to enforce it strictly.

You can also create rule sets for different contexts—one for production code, another for tests, another for documentation. This prevents the tool from flagging test-specific patterns (like intentionally incomplete error handling) as problems. Sharing a configuration file across your team ensures everyone's editor and CI pipeline check for the same issues.

Integrating Simple Inspector Into Your Workflow

The most common integration is a pre-commit hook: before you commit code, Simple Inspector runs automatically and blocks the commit if it finds errors. This catches problems before they enter version control. Git hooks are configured through a file in your .git/hooks directory, and many teams use tools like Husky to manage them without manual setup.

For continuous integration, add a Simple Inspector step to your pipeline (GitHub Actions, GitLab CI, Jenkins, or whatever your team uses). The tool exits with a non-zero status code when it finds errors, which tells your CI system to fail the build. You can configure whether warnings also fail the build or just get logged. This ensures no code with known issues reaches main or production branches.

In your editor, install a Simple Inspector extension if one exists for your IDE. This shows problems inline as you type, similar to spell-check in a word processor. Some editors can even auto-fix certain issues on save, speeding up the correction process.

Common Issues and Troubleshooting

False positives happen—the tool flags something as a problem when your code is actually correct. This usually means the rule is too strict for your use case. The fix is to disable that rule in your configuration file or add an inline comment (like // simple-inspector: ignore) to tell the tool to skip that specific line. Document why you're ignoring it so future maintainers understand the decision.

Performance can slow down on very large projects. If scanning takes too long, exclude directories you don't need to check (like node_modules, vendor, or build output) in your configuration. You can also run Simple Inspector only on changed files rather than the entire codebase, which is faster during development.

If Simple Inspector doesn't recognize your language or file type, check whether it supports that language in its documentation. Coverage varies—JavaScript and Python typically have the most rules, while newer or less common languages may have fewer checks available. You can still run the tool; it will simply report fewer issues.

When Simple Inspector Is and Isn't the Right Choice

Simple Inspector works well for small to medium teams that want lightweight, fast feedback without the overhead of enterprise tools. It's particularly useful if you're already using version control and CI/CD pipelines—it slots in naturally. The low barrier to entry makes it good for open-source projects where contributors may not have access to expensive tools.

For very large organizations with complex compliance requirements, specialized security scanning, or teams spread across many languages and frameworks, a more comprehensive tool might be necessary. Simple Inspector is intentionally simple—it does one thing well rather than trying to be everything. If you need deep architectural analysis, performance profiling, or integration with external security databases, you may need additional tools alongside it.

Frequently Asked Questions

Does Simple Inspector slow down my build?

On most projects, a full scan takes seconds to a few minutes depending on codebase size. You can speed it up by excluding large directories (like dependencies) or running it only on changed files. Many teams run a quick check on every commit and a full scan only on pull requests or scheduled intervals.

Can I use Simple Inspector with languages other than JavaScript?

Yes, Simple Inspector supports multiple languages, though the number and depth of rules varies. Check the documentation for your specific language to see what checks are available. Some languages have mature rule sets; others have fewer checks.

What's the difference between Simple Inspector and linters like ESLint?

Linters focus on code style and formatting; Simple Inspector looks for actual bugs and security issues. They're complementary—you might use ESLint to enforce consistent spacing and naming, and Simple Inspector to catch logic errors. Many teams run both.

Can I ignore specific files or folders?

Yes, through your configuration file. You can exclude directories like node_modules, test fixtures, or generated code. You can also ignore specific rules for specific files or add inline comments to skip checks on individual lines.

Does Simple Inspector require internet access?

No, it runs entirely locally. You don't need to send your code anywhere or maintain a connection to external services. This makes it fast and keeps your code private.