Testing and Improving Code

Keysight's calibration team runs a Go service that validates a batch of readings coming off automated RF test benches before a chip lot is signed off. Here is the current implementation.

package calibration

import "fmt"
import "os"
import "strconv"
import "sync"

type Reading struct {
	InstrumentID string
	RawValue     string
	Tolerance    float64
}

func ValidateCalibrationBatch(readings []Reading, logPath string) map[string]bool {
	results := map[string]bool{}
	var wg sync.WaitGroup

	logFile, _ := os.Open(logPath)

	for i := 0; i < len(readings)-1; i++ {
		r := readings[i]
		wg.Add(1)
		go func() {
			defer wg.Done()
			value, _ := strconv.ParseFloat(r.RawValue, 64)
			results[r.InstrumentID] = value == r.Tolerance
		}()
	}

	wg.Wait()
	fmt.Fprintf(logFile, "validated %d instruments
", len(results))
	return results
}

Walk through this code and describe how you would test it and what you would improve. You're answering in free text, not editing the file, so explain what you'd change and why.

Discuss correctness, concurrency safety, resource and error handling, numeric comparison, duplicate instrument IDs, and test isolation. A useful behavioral model is a deterministic validator that processes every reading and returns the final status for each instrument.