Log Analyzer

A command-line tool for analyzing and comparing JSON logs from the Applitools testing framework.

Overview

This tool helps you extract, filter, and compare structured log data from Applitools log files. It's especially useful for:

• Finding differences between test runs
• Debugging test failures
• Analyzing log patterns

Usage

Basic Commands

Compare two log files:

log-analyzer compare path/to/first.log path/to/second.log

Get information about a log file:

log-analyzer info path/to/logfile.log

Command Aliases and Shortcuts

For convenience, the following command aliases and shortcuts are available:

Command	Aliases	Description
compare	cmp	Compare logs with all options
diff		Compare logs showing only differences (shortcut for compare --diff-only)
llm		Generate LLM-friendly JSON output (shortcut for compare --diff-only -F json -c)
info	i, inspect	Display log file information

Global Options

The following options can be used with any command:

Option	Description
-F, --format <format>	Output format: text (default) or json
-c, --compact	Use compact mode for output (shorter keys, optimized structure)
-o, --output <path>	Path to output file for the results
--color <mode>	Control color output: auto (default), always, or never
-v, --verbose	Increase output verbosity (can be used multiple times)
-q, --quiet	Suppress all output except errors

Compare Options

The compare command supports several options to fine-tune your analysis:

Option	Description
-C, --component <name>	Filter logs by component (e.g., "core-universal", "socket")
--exclude-component <name>	Exclude logs with specific component
-l, --level <level>	Filter logs by log level (e.g., "INFO", "ERROR")
--exclude-level <level>	Exclude logs with specific level (e.g., "DEBUG")
-t, --contains <text>	Filter logs containing specific text
--exclude-text <text>	Exclude logs containing specific text
-d, --direction <direction>	Filter logs by communication direction (Incoming/Outgoing)
-D, --diff-only	Show only differences, skip matching objects
-f, --full	Show full JSON objects, not just the differences
-s, --sort-by <field>	Sort results by: time (default), component, level, type, or diffcount

Examples

Compare logs from two test runs showing only differences:

log-analyzer compare universal-1.log universal-2.log -D

Compare logs filtering by component and level:

log-analyzer compare universal-1.log universal-2.log -C core-universal -l ERROR

Save comparison results to a file:

log-analyzer -o diff.log compare universal-1.log universal-2.log

Filter logs by direction and output as JSON:

log-analyzer -F json compare universal-1.log universal-2.log -d Outgoing

Use compact mode with JSON output:

log-analyzer -F json -c compare universal-1.log universal-2.log

Sort results by component and exclude DEBUG level logs:

log-analyzer compare universal-1.log universal-2.log -s component --exclude-level DEBUG

Use environment variables for common settings:

# Set in .env file or export in shell
export LOG_ANALYZER_FORMAT=json
export LOG_ANALYZER_EXCLUDE_LEVEL=DEBUG
log-analyzer compare universal-1.log universal-2.log

Use diff command with increased verbosity:

log-analyzer diff universal-1.log universal-2.log -v -s diffcount

The diff command is a shortcut for compare with --diff-only:

# These commands are equivalent:
log-analyzer diff universal-1.log universal-2.log
log-analyzer compare universal-1.log universal-2.log -D

Use the llm command for machine-readable JSON output:

# Generate compact JSON diff for LLM consumption:
log-analyzer llm universal-1.log universal-2.log > diff.json

# Equivalent to:
log-analyzer compare universal-1.log universal-2.log -D -F json -c > diff.json

Features

• Structured log parsing: Automatically extracts and parses JSON payloads
• Intelligent comparison: Semantically compares JSON objects, regardless of property order
• Advanced filtering: Include/exclude logs by component, level, content, or direction
• Log categorization: Automatically categorizes logs into events, commands, and requests
• Multiple output formats: Choose between human-readable text or JSON for programmatic processing
• Detailed output: Clear, readable comparison output with highlighting for differences
• Flexible output options: Save results to a file, use compact mode for more concise output
• Optimized CLI: Well-organized command structure with aliases and global options
• Environment configuration: Set defaults via environment variables or .env file
• Output customization: Control colors, verbosity, and sorting for better analysis

CLI Enhancements

This tool includes several advanced CLI features to improve usability:

Command Shortcuts and Aliases

• Command aliases: Use shorthand commands like cmp for compare and i for info
• Specialized commands: Built-in shortcut commands that combine commonly-used options:
  • diff command: Automatically shows only differences (equivalent to compare --diff-only)
  • llm command: Optimized for LLM consumption (equivalent to compare --diff-only -F json -c)

Advanced Filtering

• Include filters: Filter logs by component, level, or text content
• Exclude filters: Skip logs with specified component, level, or text
• Directional filtering: Filter by communication direction (incoming or outgoing)
• Combined filtering: Mix and match filters for precise log selection

Output Control

• Format selection: Choose between human-readable text or JSON output
• Compact mode: More concise output with shortened keys for space efficiency
• Color control: Configure when colors are used (auto, always, or never)
• Verbosity levels: Control detail level from quiet (errors only) to verbose (all details)
• Custom sorting: Sort results by time, component, level, type, or difference count

Environment Configuration

• Environment variables: Configure options via environment variables (prefixed with LOG_ANALYZER_)
• .env support: Store common configurations in a .env file for persistence
• Example configuration: See .env.example for available environment options

Complete Command Reference

Global Options

Option	Environment Variable	Description
-F, --format <text|json>	LOG_ANALYZER_FORMAT	Output format (text or JSON)
-c, --compact	LOG_ANALYZER_COMPACT	Use compact mode for output
-o, --output <path>	LOG_ANALYZER_OUTPUT_FILE	Path to output file for results
--color <auto|always|never>	LOG_ANALYZER_COLOR	Control color output
-v, --verbose	LOG_ANALYZER_VERBOSE	Increase verbosity (can be used multiple times)
-q, --quiet	LOG_ANALYZER_QUIET	Be quiet, show only errors

Commands

compare (aliases: cmp)

Compare two log files with all options

log-analyzer compare [OPTIONS] <FILE1> <FILE2>

Option	Environment Variable	Description
-C, --component <name>	LOG_ANALYZER_COMPONENT	Filter logs by component
--exclude-component <name>	LOG_ANALYZER_EXCLUDE_COMPONENT	Exclude logs with specific component
-l, --level <level>	LOG_ANALYZER_LEVEL	Filter logs by level
--exclude-level <level>	LOG_ANALYZER_EXCLUDE_LEVEL	Exclude logs with specific level
-t, --contains <text>	LOG_ANALYZER_CONTAINS	Filter logs containing specific text
--exclude-text <text>	LOG_ANALYZER_EXCLUDE_TEXT	Exclude logs containing specific text
-d, --direction <Incoming|Outgoing>	LOG_ANALYZER_DIRECTION	Filter logs by direction
-D, --diff-only		Show only differences, skip matching objects
-f, --full		Show full JSON objects, not just differences
-s, --sort-by <field>	LOG_ANALYZER_SORT_BY	Sort by: time, component, level, type, diffcount

diff

Compare logs showing only differences (shortcut for compare --diff-only)

log-analyzer diff [OPTIONS] <FILE1> <FILE2>

Supports all options as compare except --diff-only which is always enabled.

llm

Generate LLM-friendly compact JSON output (shortcut for compare --diff-only -F json -c)

log-analyzer llm [OPTIONS] <FILE1> <FILE2>

Supports filtering options from compare but always uses JSON format, compact mode, and shows only differences.

info (aliases: i, inspect)

List all components, event types, log levels, and detailed statistics in a log file

log-analyzer info [OPTIONS] <FILE>

Option	Description
-s, --samples	Show sample log messages for each component
-j, --json-schema	Display detailed JSON schema information for event payloads
-C, --component <n>	Filter logs by component
-l, --level <level>	Filter logs by log level
-p, --payloads	Show payload statistics for each event/command/request type
-t, --timeline	Show detailed timeline analysis with event distribution

The enhanced info command provides deep insights into log structure and content:

# Show sample log messages for each component
log-analyzer info --samples universal-1.log

# Display detailed timeline analysis with event distribution
log-analyzer info --timeline universal-1.log

# Show JSON schema information and payload statistics
log-analyzer info --json-schema --payloads universal-1.log

# Filter to analyze only specific component
log-analyzer info --component core-ufg --timeline universal-1.log

# Comprehensive analysis with all options
log-analyzer info --samples --json-schema --payloads --timeline universal-1.log