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Merged
naheel0 merged 6 commits into from
Mar 4, 2026
Merged

Add --json option and improve CLI output #44

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cc20a41
Add --json option and improve CLI output
naheel0 Mar 4, 2026
c005e83
Update package.json
naheel0 Mar 4, 2026
f128793
Merge branch 'main' into index
naheel0 Mar 4, 2026
e66b47a
Initial plan
Copilot Mar 4, 2026
86e30f0
Replace static chalk require with dynamic import in bin/index.js
Copilot Mar 4, 2026
b7833a6
Merge pull request #45 from BeyteFlow/copilot/sub-pr-44
jaseel0 Mar 4, 2026
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28 changes: 26 additions & 2 deletions README.md
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Original file line number Diff line number Diff line change
Expand Up @@ -54,8 +54,32 @@ npm install -g errlens

---

## ⚡ Quick Start

```bash
# Analyze an error message
errlens analyze "TypeError: Cannot read property 'name' of undefined"

# Run a script with error monitoring
errlens run your-script.js

# Get JSON output for CI/CD pipelines
errlens analyze "is not a function" --json
```

---

## 🛠 Usage

### Available Commands

```bash
errlens run <file> [--json] # Run a script and analyze any crashes
errlens analyze <error> [--json] # Analyze a specific error message
errlens --version # Show version information
errlens --help # Show help
```

### 1️⃣ Automatic Monitoring (The "Pro" Way)

Run your script through ErrLens. If it crashes, ErrLens intercepts the error and explains the fix before the process exits.
Expand All @@ -71,7 +95,7 @@ errlens run your-app.js
Found a weird error in your logs? Just paste the message:

```bash
errlens "TypeError: Cannot read properties of undefined"
errlens analyze "TypeError: Cannot read properties of undefined"
```

---
Expand All @@ -81,7 +105,7 @@ errlens "TypeError: Cannot read properties of undefined"
Get machine-readable results for your own tooling or automated reports:

```bash
errlens "is not a function" --json
errlens analyze "is not a function" --json
```

Run a script and write the JSON report directly to a file in CI:
Expand Down
91 changes: 57 additions & 34 deletions bin/index.js
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Original file line number Diff line number Diff line change
Expand Up @@ -2,36 +2,40 @@

const { Command } = require("commander");
const { spawn } = require("child_process");

const chalk = require("chalk");
const path = require("path");
const { findError } = require("../lib/matcher");
const { formatError } = require("../lib/formatter");

const { version } = require("../package.json");

const program = new Command();

program
.name("errlens")
.description("Professional JS Error Analytics")
.version(version);
.version(version)
.option("--json", "Output JSON instead of pretty UI"); // ✅ GLOBAL OPTION

// ----------------- RUN COMMAND -----------------
program
.command("run <file>")
.option('--json', 'Output JSON instead of pretty UI')
.description("Run a Javascript file and analyze crashes")
.action(async (file, options) => {
.action(async (file) => {
const { default: ora } = await import("ora");
const { default: chalk } = await import("chalk");

const isJson = Boolean(program.opts().json);
const filePath = path.resolve(process.cwd(), file);
const isJson = Boolean(options.json);
const spinner = isJson ? null : ora(`Running ${chalk.yellow(file)}...`).start();
const spinner = isJson
? null
: ora(`Running ${chalk.yellow(file)}...`).start();

const child = spawn(process.execPath, [filePath], { stdio: ["inherit", "pipe", "pipe"] });
const child = spawn(process.execPath, [filePath], {
stdio: ["inherit", "pipe", "pipe"],
});

let errorOutput = "";

// Stream logs to terminal in real-time
// Stream stdout only in pretty mode
child.stdout.on("data", (data) => {
if (!isJson) {
spinner.stop();
Expand All @@ -40,7 +44,7 @@ program
}
});

// Capture stderr for analysis
// Capture stderr (DO NOT print in JSON mode)
child.stderr.on("data", (data) => {
errorOutput += data.toString();

Expand All @@ -50,34 +54,46 @@ program
});

child.on("close", (code, signal) => {
if (!isJson) {
if (!isJson && spinner) {
spinner.stop();
}

const { count, matches } = findError(errorOutput);

// Process killed by signal
if (code === null) {
const result = { code: 1, count, matches };

if (isJson) {
const result = { code: 1, count, matches };
console.log(JSON.stringify(result, null, 2));
} else {
console.log(chalk.red.bold(`\n⚠️ Process killed by signal: ${signal}`));
console.log(
chalk.red.bold(`\n⚠️ Process killed by signal: ${signal}`)
);
}

process.exit(1);
return;
}

// JSON MODE
if (isJson) {
const result = { code, count, matches };
console.log(JSON.stringify(result, null, 2));
} else if (code === 0) {
console.log(chalk.green.bold("\n✨ Process finished successfully."));
console.log(JSON.stringify({ code, count, matches }, null, 2));
process.exit(code ?? 1);
}

// PRETTY MODE
if (code === 0) {
console.log(chalk.green.bold("\n✨ Process finished successfully."));
} else {
if (count > 0) {
console.log(chalk.bold.cyan(`\n🚀 ErrLens Analysis (${count} Issue(s)):`));
matches.forEach(m => { console.log(formatError(m)); }); // Pretty UI only here
console.log(
chalk.bold.cyan(`\n🚀 ErrLens Analysis (${count} Issue(s)):`)
);
matches.forEach((m) => console.log(formatError(m)));
} else {
console.log(chalk.red.bold("\n❌ Crash detected (No known fix in database):"));
console.log(
chalk.red.bold("\n❌ Crash detected (No known fix in database):")
);
console.log(chalk.gray(errorOutput));
}
}
Expand All @@ -86,42 +102,49 @@ program
});

child.on("error", (err) => {
const result = { code: 1, count: 0, matches: [] };

if (isJson) {
const result = { code: 1, count: 0, matches: [] };
console.log(JSON.stringify(result, null, 2));
} else {
spinner.fail(chalk.red(`System Error: ${err.message}`));
console.log(chalk.red(`System Error: ${err.message}`));
}

process.exit(1);
});
Comment on lines 104 to 114
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@coderabbitai coderabbitai bot Mar 4, 2026

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⚠️ Potential issue | 🟡 Minor

Stop spinner before printing error in pretty mode.

The error handler doesn't stop the spinner before logging the error message. In pretty mode, this can cause garbled output where the spinner animation overlaps with the error text.

🛡️ Proposed fix 
     child.on("error", (err) => {
       const result = { code: 1, count: 0, matches: [] };
 
       if (isJson) {
         console.log(JSON.stringify(result, null, 2));
       } else {
+        if (spinner) spinner.stop();
         console.log(chalk.red(`System Error: ${err.message}`));
       }
 
       process.exit(1);
     });
📝 Committable suggestion

‼️ IMPORTANT
Carefully review the code before committing. Ensure that it accurately replaces the highlighted code, contains no missing lines, and has no issues with indentation. Thoroughly test & benchmark the code to ensure it meets the requirements.

Suggested change
child.on("error", (err) => {
const result = { code: 1, count: 0, matches: [] };
if (isJson) {
const result = { code: 1, count: 0, matches: [] };
console.log(JSON.stringify(result, null, 2));
} else {
spinner.fail(chalk.red(`System Error: ${err.message}`));
console.log(chalk.red(`System Error: ${err.message}`));
}
process.exit(1);
});
child.on("error", (err) => {
const result = { code: 1, count: 0, matches: [] };
if (isJson) {
console.log(JSON.stringify(result, null, 2));
} else {
if (spinner) spinner.stop();
console.log(chalk.red(`System Error: ${err.message}`));
}
process.exit(1);
});
🤖 Prompt for AI Agents 
Verify each finding against the current code and only fix it if needed.

In `@bin/index.js` around lines 104 - 114, The error handler for child.on("error",
(err) => { ... }) must stop the CLI spinner before writing the pretty (non-JSON)
error to avoid overlapping output; update the handler to check for the spinner
instance (e.g., spinner) and call its stop/clear method (or stopSpinner())
before calling console.log(chalk.red(...)) while leaving JSON output path
unchanged and then call process.exit(1).

});

// ----------------- ANALYZE COMMAND -----------------
program
.arguments("<errorString>") // default command if no "run"
.command("analyze <errorString>")
.description("Analyze a specific error string")
.option('--json', 'Output result in JSON format')
.action((errorString, options) => {
.action(async (errorString) => {
const { default: chalk } = await import("chalk");
const isJson = Boolean(program.opts().json);
const { count, matches } = findError(errorString);
const exitCode = count > 0 ? 1 : 0;
const isJson = Boolean(options.json);

if (isJson) {
console.log(JSON.stringify({ code: exitCode, count, matches }, null, 2));
console.log(
JSON.stringify({ code: exitCode, count, matches }, null, 2)
);
process.exit(exitCode);
return;
}

if (count > 0) {
console.log(chalk.bold.cyan(`\n🚀 ErrLens Analysis (${count} Issue(s)):`));
matches.forEach(m => { console.log(formatError(m)); }); // Pretty UI
console.log(
chalk.bold.cyan(`\n🚀 ErrLens Analysis (${count} Issue(s)):`)
);
matches.forEach((m) => console.log(formatError(m)));
} else {
console.log(chalk.red.bold("\n❌ Crash detected (No known fix in database):"));
console.log(
chalk.red.bold("\n❌ Crash detected (No known fix in database):")
);
console.log(chalk.gray(errorString));
}

process.exit(exitCode);
});

// ----------------- PARSE ARGUMENTS -----------------
// ----------------- PARSE -----------------
program.parse(process.argv);