Logging¶

The Log global provides functions to write messages to Frasy's Log Window panel. Messages are tagged with the UUT number automatically (e.g., UUT1, UUT2) so you can identify which UUT produced each log entry in multi-UUT environments.

Log Levels¶

Function	Level	Color	Use For
`Log.T(message)`	Trace	Gray	Extremely verbose diagnostics (usually filtered out)
`Log.D(message)`	Debug	Cyan	Development-time debugging info
`Log.I(message)`	Info	Green	Normal operational messages
`Log.W(message)`	Warning	Yellow	Unexpected but recoverable situations
`Log.E(message)`	Error	Red	Failures that affect test results
`Log.C(message)`	Critical	Red/Bold	Unrecoverable errors

All functions take a single string argument. They do not support format strings directly — use string.format() or concatenation.

Usage¶

Log.I("Starting power-on sequence")
Log.D("Voltage reading: " .. tostring(voltage))
Log.W("Current is near the upper limit")
Log.E("Communication timeout after 3 retries")

With String Formatting¶

Log.I(string.format("Channel %d: %.3f V", channel, voltage))
Log.D(string.format("Attempt %d/%d", retry, maxRetries))
Log.W(string.format("Temperature %.1f°C exceeds threshold", temp))

Where Messages Appear¶

Log messages appear in the Log Window panel (F2). Each entry shows:

Timestamp — when the message was produced
Source — the UUT tag (e.g., UUT1)
Level — the severity level
Message — your text
Source location — file and line number (if enabled in config)

Messages are also written to the application's log file on disk.

Filtering¶

The Log Window panel supports filtering by:

Level — toggle visibility per level (trace, debug, info, warn, error, critical)
Text — free-text filter in the search bar
Source — per-logger level overrides in config.json

To reduce noise from a specific subsystem at the config level:

"LogWindow": {
    "Loggers": {
        "SlCan": 2
    }
}

Logger levels are integers matching spdlog levels: 0 = trace, 1 = debug, 2 = info, 3 = warn, 4 = error, 5 = critical.

Behavior During Stages¶

Logging works in all stages (generation, validation, execution). This can be useful for debugging environment loading or requirement resolution.

Log.D("Environment loaded, UUT count: " .. #Context.map.uuts)

Best Practices¶

Use Log.I for test progress. Log when a sequence or significant step starts/completes. The orchestrator already logs test pass/fail — don't duplicate that.
Use Log.D for measurements. Log raw values before assertion so failures can be diagnosed from the log without re-running.
Use Log.W for soft limits. If a value passes but is close to the boundary, warn so operators notice drift.
Use Log.E sparingly. The framework logs errors for failed expectations automatically. Only use Log.E for issues that aren't captured by expectations (hardware communication problems, unexpected states).
Avoid logging in tight loops. Logging is relatively expensive. Don't log inside measurement averaging loops or polling loops — log the summary instead.
Use string.format for numeric values. Truncate floats to reasonable precision: string.format("%.3f", v) rather than tostring(v) which may produce excessive decimals.

Example¶

Sequence("Communication", function()
    Test("RS485 Echo", function()
        Log.I("Testing RS485 echo at 115200 baud")

        local sent = 0xA5
        local received = rs485Send(sent)

        Log.D(string.format("Sent: 0x%02X, Received: 0x%02X", sent, received or 0))

        if received == nil then
            Log.E("No response from RS485 device")
        end

        Expect(received, "Echo Response"):ToBeEqual(sent)
    end)
end)