use an UUID for the loop variable

Author: ipavlic

go.mod

@@ -15,6 +15,7 @@ require (
 	github.com/clipperhouse/stringish v0.1.1 // indirect
 	github.com/clipperhouse/uax29/v2 v2.3.0 // indirect
 	github.com/fatih/color v1.18.0 // indirect
+	github.com/google/uuid v1.6.0 // indirect
 	github.com/inconshreveable/mousetrap v1.1.0 // indirect
 	github.com/mattn/go-colorable v0.1.14 // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect

go.sum

@@ -7,6 +7,8 @@ github.com/clipperhouse/uax29/v2 v2.3.0/go.mod h1:Wn1g7MK6OoeDT0vL+Q0SQLDz/KpfsV
 github.com/cpuguy83/go-md2man/v2 v2.0.6/go.mod h1:oOW0eioCTA6cOiMLiUPZOpcVxMig6NIQQ7OS05n1F4g=
 github.com/fatih/color v1.18.0 h1:S8gINlzdQ840/4pfAwic/ZE0djQEH3wM94VfqLTZcOM=
 github.com/fatih/color v1.18.0/go.mod h1:4FelSpRwEGDpQ12mAdzqdOukCy4u8WUtOY6lkT/6HfU=
+github.com/google/uuid v1.6.0 h1:NIvaJDMOsjHA8n1jAhLSgzrAzy1Hgr+hNrb57e+94F0=
+github.com/google/uuid v1.6.0/go.mod h1:TIyPZe4MgqvfeYDBFedMoGGpEw/LqOeaOT+nhxU+yHo=
 github.com/inconshreveable/mousetrap v1.1.0 h1:wN+x4NVGpMsO7ErUn/mUI3vEoE6Jt13X2s0bqwp9tc8=
 github.com/inconshreveable/mousetrap v1.1.0/go.mod h1:vpF70FUmC8bwa3OWnCshd2FqLfsEA9PFc4w1p2J65bw=
 github.com/mattn/go-colorable v0.1.14 h1:9A9LHSqF/7dyVVX6g0U9cwm9pG3kP9gSzcuIPHPsaIE=

pkg/generator/generator.go

@@ -6,25 +6,41 @@ import (
 	"strings"
 	"text/template"
 
+	"github.com/google/uuid"
 	"github.com/ipavlic/apex-benchmark-cli/pkg/types"
 )
 
+// templateData extends CodeSpec with additional template variables
+type templateData struct {
+	types.CodeSpec
+	LoopVar string
+}
+
 // Generate creates Apex code from a CodeSpec using the template
 func Generate(spec types.CodeSpec) (string, error) {
 	// Validate input
 	if err := validateSpec(spec); err != nil {
 		return "", err
 	}
 
+	// Generate unique loop variable name to avoid conflicts with user code
+	loopVar := "i_" + strings.ReplaceAll(uuid.New().String(), "-", "_")
+
 	// Parse template
 	tmpl, err := template.New("apex").Parse(apexTemplate)
 	if err != nil {
 		return "", fmt.Errorf("failed to parse template: %w", err)
 	}
 
+	// Prepare template data
+	data := templateData{
+		CodeSpec: spec,
+		LoopVar:  loopVar,
+	}
+
 	// Execute template
 	var buf bytes.Buffer
-	if err := tmpl.Execute(&buf, spec); err != nil {
+	if err := tmpl.Execute(&buf, data); err != nil {
 		return "", fmt.Errorf("failed to execute template: %w", err)
 	}
 

pkg/generator/generator_test.go

@@ -29,8 +29,8 @@ func TestGenerate_BasicCode(t *testing.T) {
 		"Integer warmupIterations = 10;",
 		"Integer measurementIterations = 100;",
 		"BENCH_RESULT:",
-		"for (Integer i = 0; i < warmupIterations; i++)",
-		"for (Integer i = 0; i < measurementIterations; i++)",
+		"< warmupIterations;",  // Loop uses UUID-based variable
+		"< measurementIterations;", // Loop uses UUID-based variable
 		"Long wallStart = System.now().getTime();",
 		"Integer cpuStart = Limits.getCpuTime();",
 	}

pkg/generator/templates.go

@@ -14,7 +14,7 @@ Integer warmupIterations = {{.Warmup}};
 Integer measurementIterations = {{.Iterations}};
 
 // Warmup phase - JIT optimization
-for (Integer i = 0; i < warmupIterations; i++) {
+for (Integer {{.LoopVar}} = 0; {{.LoopVar}} < warmupIterations; {{.LoopVar}}++) {
     {{.UserCode}}
 }
 
@@ -37,7 +37,7 @@ Integer dmlStatementsBefore = Limits.getDmlStatements();
 Integer soqlQueriesBefore = Limits.getQueries();
 {{end}}
 
-for (Integer i = 0; i < measurementIterations; i++) {
+for (Integer {{.LoopVar}} = 0; {{.LoopVar}} < measurementIterations; {{.LoopVar}}++) {
     {{if .TrackHeap}}
     Long heapBefore = Limits.getHeapSize();
     {{end}}