more tests

Author: lanrat

optimization_test.go

@@ -0,0 +1,97 @@
+package extsort_test
+
+import (
+	"context"
+	"os"
+	"testing"
+
+	"github.com/lanrat/extsort"
+)
+
+// TestSingleChunkOptimization verifies that small datasets don't create temp files
+func TestSingleChunkOptimization(t *testing.T) {
+	// Small dataset that should fit in a single chunk
+	inputChan := make(chan extsort.SortType, 10)
+	for i := 9; i >= 0; i-- { // reverse order to ensure sorting happens
+		inputChan <- val{Key: i, Order: i}
+	}
+	close(inputChan)
+
+	// Create sorter with default config (ChunkSize = 1M)
+	sort, outChan, errChan := extsort.New(inputChan, fromBytesForTest, KeyLessThan, nil)
+
+	// Count temp files before
+	tempDir := os.TempDir()
+	beforeFiles, err := os.ReadDir(tempDir)
+	if err != nil {
+		t.Fatalf("Failed to read temp dir: %v", err)
+	}
+	beforeCount := len(beforeFiles)
+
+	// Sort
+	sort.Sort(context.Background())
+
+	// Read results
+	results := make([]val, 0, 10)
+	for rec := range outChan {
+		results = append(results, rec.(val))
+	}
+	if err := <-errChan; err != nil {
+		t.Fatalf("Sort error: %v", err)
+	}
+
+	// Count temp files after
+	afterFiles, err := os.ReadDir(tempDir)
+	if err != nil {
+		t.Fatalf("Failed to read temp dir: %v", err)
+	}
+	afterCount := len(afterFiles)
+
+	// Verify results are sorted
+	for i := 0; i < len(results); i++ {
+		if results[i].Key != i {
+			t.Errorf("Expected Key %d at position %d, got %d", i, i, results[i].Key)
+		}
+	}
+
+	// Verify no additional temp files were created
+	if afterCount > beforeCount {
+		t.Errorf("Expected no temp files to be created for single chunk, but temp file count increased from %d to %d", beforeCount, afterCount)
+	}
+
+	t.Logf("Single chunk optimization working: no temp files created for 10 items")
+}
+
+// TestMultiChunkStillUsesTempFiles verifies that large datasets still use temp files
+func TestMultiChunkStillUsesTempFiles(t *testing.T) {
+	// Use a very small chunk size to force multiple chunks
+	config := extsort.DefaultConfig()
+	config.ChunkSize = 2 // Force multiple chunks for small dataset
+
+	inputChan := make(chan extsort.SortType, 10)
+	for i := 9; i >= 0; i-- {
+		inputChan <- val{Key: i, Order: i}
+	}
+	close(inputChan)
+
+	sort, outChan, errChan := extsort.New(inputChan, fromBytesForTest, KeyLessThan, config)
+	sort.Sort(context.Background())
+
+	// Read results to completion
+	results := make([]val, 0, 10)
+	for rec := range outChan {
+		results = append(results, rec.(val))
+	}
+	if err := <-errChan; err != nil {
+		t.Fatalf("Sort error: %v", err)
+	}
+
+	// Verify results are sorted
+	for i := 0; i < len(results); i++ {
+		if results[i].Key != i {
+			t.Errorf("Expected Key %d at position %d, got %d", i, i, results[i].Key)
+		}
+	}
+
+	t.Logf("Multi-chunk path still working with small chunk size")
+}