Add JSON Lines support for .log files

- Handle .log files as sequences of JSON objects (JSON Lines/NDJSON format)
- Convert each line to JSON object and combine into array (like jq -s)
- Maintain existing .json file handling for standard JSON format
- Add detailed error messages for invalid JSON lines
- Update documentation to explain both file format supports

README.md

@@ -10,7 +10,7 @@ A React-based web application for testing and validating JMESPath expressions ag
 
 - 🎯 **Real-time Evaluation**: JMESPath expressions are evaluated instantly as you type
 - 📝 **JSON Validation**: Built-in JSON syntax validation and error reporting
-- 📁 **File Upload**: Load JSON data directly from local files
+- 📁 **File Upload**: Load JSON data directly from local files (supports JSON Lines format for .log files)
 - 🎨 **Bootstrap UI**: Clean, responsive interface with Bootstrap styling
 - 🔄 **Sample Data**: Pre-loaded examples to get started quickly
 - 📱 **Responsive Design**: Works on desktop, tablet, and mobile devices
@@ -75,7 +75,9 @@ npm run docker:run
 
 1. **Enter a JMESPath expression** in the top input field (e.g., `people[*].name`)
 2. **Add JSON data** using one of these methods:
-   - **Load from disk**: Click "📁 Load from Disk" to upload a JSON file
+   - **Load from disk**: Click "📁 Load from Disk" to upload files
+     - `.json` files: Standard JSON format
+     - `.log` files: JSON Lines format (each line is a JSON object, automatically converted to array)
    - **Paste or type**: Enter JSON data directly in the bottom-left textarea
    - **Load sample**: Use the "Load Sample" button for quick testing
 3. **View the results** in the bottom-right output area

src/App.js

@@ -127,12 +127,35 @@ function App() {
         reader.onload = (e) => {
           try {
             const content = e.target.result;
-            // Try to parse as JSON to validate
-            JSON.parse(content);
-            setJsonData(content);
+            let jsonContent;
+            
+            // Handle .log files as sequences of JSON objects (JSON Lines format)
+            if (file.name.toLowerCase().endsWith('.log')) {
+              const lines = content.split('\n')
+                .map(line => line.trim())
+                .filter(line => line.length > 0);
+              
+              const jsonObjects = [];
+              for (const line of lines) {
+                try {
+                  const obj = JSON.parse(line);
+                  jsonObjects.push(obj);
+                } catch (lineError) {
+                  throw new Error(`Invalid JSON on line: "${line.substring(0, 50)}..." - ${lineError.message}`);
+                }
+              }
+              
+              jsonContent = JSON.stringify(jsonObjects, null, 2);
+            } else {
+              // Handle .json files as regular JSON
+              JSON.parse(content); // Validate JSON
+              jsonContent = content;
+            }
+            
+            setJsonData(jsonContent);
             setJsonError('');
           } catch (err) {
-            setJsonError(`Invalid JSON file: ${err.message}`);
+            setJsonError(`Invalid file content: ${err.message}`);
           }
         };
         reader.readAsText(file);