Debug File Format

The Testomatio Reporter debug file format is used to capture and replay test execution data. This specification defines the structure, storage location, and content of debug files.

File Format

Debug files use JSONL (JSON Lines) format, not standard JSON. Each line contains a single JSON object representing a specific action or data entry. This format allows for streaming processing and incremental writing.

{"t":"+0ms","datetime":"2024-01-15T10:30:00.000Z","timestamp":1705315800000}
{"t":"+5ms","data":"variables","testomatioEnvVars":{"TESTOMATIO":"abc123"}}
{"t":"+10ms","action":"createRun","params":{"title":"Test Run"}}

File Storage

Latest Debug Run

The latest debug run is always accessible at:

./testomatio.debug.json

Run history can be found in /tmp/testomatio.debug.<datetime>.json (ISO 8601 format)

File Creation

• Files are created when TESTOMATIO_DEBUG or DEBUG environment variables are set
• A new timestamped file is created for each test session
• The symlink is updated to point to the latest file
• If symlink creation fails, it’s logged but doesn’t prevent file creation

Entry Structure

Every entry in the debug file follows this base structure:

{
  "t": "+{time}ms" // Time elapsed since last action (required)
  // ... action-specific fields
}

Time Field (t)

• Format: "+{milliseconds}ms" (e.g., "+150ms", "+2.5s")
• Represents time passed since the previous action
• Generated using prettyMs() for human readability

Entry Types

1. Session Initialization

Timestamp Entry:

{
  "t": "+0ms",
  "datetime": "2024-01-15T10:30:00.000Z",
  "timestamp": 1705315800000
}

Environment Variables:

{
  "t": "+5ms",
  "data": "variables",
  "testomatioEnvVars": {
    "TESTOMATIO": "api_key_here",
    "TESTOMATIO_TITLE": "Test Run Title",
    "TESTOMATIO_ENV": "staging"
  }
}

Store Data:

{
  "t": "+10ms",
  "data": "store",
  "store": {}
}

2. Test Run Management Actions

Prepare Run:

{
  "t": "+15ms",
  "action": "prepareRun",
  "data": {
    "pipe": "testomatio",
    "pipeOptions": "tag-name=smoke"
  }
}

Create Run:

{
  "t": "+20ms",
  "action": "createRun",
  "params": {
    "title": "Test Run Title",
    "env": "staging",
    "parallel": true,
    "batchMode": "auto"
  }
}

Finish Run:

{
  "t": "+5000ms",
  "actions": "finishRun",
  "params": {
    "status": "finished",
    "parallel": true
  }
}

3. Test Execution Actions

Add Single Test:

{
  "t": "+100ms",
  "action": "addTest",
  "runId": "run-id-uuid",
  "testId": {
    "id": "test-unique-id",
    "title": "Test case title",
    "status": "passed",
    "time": 1500,
    "rid": "request-id",
    "suite": "Suite Name",
    "file": "path/to/test.js",
    "error": "Error message if failed",
    "steps": [
      {
        "title": "Step description",
        "status": "passed",
        "time": 500
      }
    ],
    "artifacts": [
      {
        "name": "screenshot.png",
        "type": "image/png",
        "path": "/path/to/screenshot.png"
      }
    ],
    "files": ["/path/to/attachment1.txt", "/path/to/attachment2.log"]
  }
}

Add Tests Batch:

{
  "t": "+200ms",
  "action": "addTestsBatch",
  "runId": "run-id-uuid",
  "tests": [
    {
      "id": "test-1",
      "title": "First test",
      "status": "passed",
      "time": 800
    },
    {
      "id": "test-2",
      "title": "Second test",
      "status": "failed",
      "time": 1200,
      "error": "Assertion failed"
    }
  ]
}

Field Definitions

Common Fields

Field	Type	Required	Description
t	string	Yes	Time elapsed since last action (e.g., “+150ms”)
action	string	Conditional	Action type identifier (most actions)
actions	string	Conditional	Action type identifier (for finishRun only)
data	string	Conditional	Data type identifier for non-action entries

Action-Specific Fields

createRun / finishRun

Field	Type	Required	Description
params	object	Yes	Parameters for run creation/completion
params.title	string	No	Test run title
params.env	string	No	Environment name
params.parallel	boolean	No	Whether run supports parallel execution
params.status	string	No	Run status (for finishRun)
params.batchMode	string	No	Batch upload mode: auto, manual, or disabled

addTest / addTestsBatch

Field	Type	Required	Description
runId	string	No	UUID of the test run
testId	object	Yes*	Single test data (for addTest)
tests	array	Yes*	Array of test objects (for addTestsBatch)

*Either testId or tests is required depending on action type.

Test Object Fields

Field	Type	Required	Description
id	string	Yes	Unique test identifier
title	string	Yes	Test case title
status	string	Yes	Test status: “passed”, “failed”, “skipped”, “pending”
time	number	No	Execution time in milliseconds
rid	string	No	Request ID for deduplication
suite	string	No	Test suite name
file	string	No	Test file path
error	string	No	Error message for failed tests
stack	string	No	Stack trace for failed tests
code	string	No	Test source code
steps	array	No	Array of test step objects
artifacts	array	No	Array of artifact objects
files	array	No	Array of file paths

Step Object Fields

Field	Type	Required	Description
title	string	Yes	Step description
status	string	Yes	Step status
time	number	No	Step execution time
error	string	No	Error message for failed steps

Artifact Object Fields

Field	Type	Required	Description
name	string	Yes	Artifact file name
type	string	No	MIME type
path	string	No	File system path
url	string	No	Remote URL
size	number	No	File size in bytes

Environment Variables Entry

Field	Type	Required	Description
data	string	Yes	Must be “variables”
testomatioEnvVars	object	Yes	All TESTOMATIO_* environment variables

Store Entry

Field	Type	Required	Description
data	string	Yes	Must be “store”
store	object	Yes	Internal store data

Status Values

Test Status

• "passed" - Test executed successfully
• "failed" - Test failed with assertion or runtime error
• "skipped" - Test was skipped intentionally
• "pending" - Test is pending implementation
• "retried" - Test was retried

Run Status

• "started" - Run has been initiated
• "finished" - Run completed normally
• "failed" - Run failed due to system error
• "interrupted" - Run was interrupted

File Processing Rules

Line Processing

1. Each line must be valid JSON
2. Empty lines and whitespace-only lines are ignored
3. Parse errors are logged but don’t stop processing
4. Maximum of 3 parse errors are shown, then summarized

Test Deduplication

• Tests with rid (request ID) are deduplicated
• Multiple entries with same rid are merged
• Later entries can override earlier fields
• Arrays (files, artifacts) are merged, not replaced
• Tests without rid are never deduplicated

Data Merging

When merging duplicate tests:

1. Non-null/non-undefined values override null/undefined
2. Non-empty arrays override empty arrays
3. Files and artifacts arrays are concatenated
4. Other fields use “last value wins” strategy

Usage Examples

Enabling Debug Output

export TESTOMATIO_DEBUG=1

export DEBUG=1


npm test

Replay from Debug File

npx testomatio-reporter replay


npx testomatio-reporter replay /tmp/testomatio.debug.2025-01-15T14-30-45.json

Reading Debug Files

import fs from 'fs';

// Read debug file line by line
// Use project root path (symlink to latest run in /tmp)
const content = fs.readFileSync('./testomatio.debug.json', 'utf-8');
const lines = content
  .trim()
  .split('\n')
  .filter(line => line.trim());

for (const line of lines) {
  try {
    const entry = JSON.parse(line);
    console.log(`[${entry.t}] ${entry.action || entry.data}`);
  } catch (err) {
    console.error('Parse error:', err.message);
  }
}

Implementation Notes

File Creation

• Debug files are created in the DebugPipe constructor when enabled
• Each test session gets a unique timestamped filename
• Symlink provides consistent access to the latest file

Batch Processing

• Tests can be logged individually or in batches
• Batched tests are gathered in memory and written on sync() / finishRun()

Error Handling

• Parse errors don’t stop file processing
• Missing required fields may cause replay failures
• Malformed entries are skipped with warnings

Performance Considerations

• Files are written synchronously for data integrity
• Large test suites may produce substantial debug files
• Consider file cleanup policies for long-running systems

Version Compatibility

This specification is compatible with:

• Testomatio Reporter v2.0.0+
• All major test frameworks (Jest, Mocha, Playwright, etc.)
• Node.js 14+ environments

Security Notes

• Debug files may contain sensitive data from environment variables
• Store debug files securely and clean them regularly
• Consider filtering sensitive variables before logging
• Debug files are world-readable by default in temp directories