Refactor for safer handling of strings

cmd/benchmark.go

@@ -369,20 +369,12 @@ func rallyCommandAction(cmd *cobra.Command, args []string) error {
 }
 
 func getPackageNameAndVersion(packageFromRegistry string) (string, string, error) {
-	packageData := strings.SplitN(packageFromRegistry, "-", 2)
-
-	if len(packageData) != 2 {
-		return "", "", fmt.Errorf("package name and version from registry not valid (%s)", packageFromRegistry)
-	}
-
-	packageName := packageData[0]
-	packageVersion := packageData[1]
-
-	if len(packageName) > 0 && len(packageVersion) == 0 {
+	name, version, valid := strings.Cut(packageFromRegistry, "-")
+	if !valid || name == "" || version == "" {
 		return "", "", fmt.Errorf("package name and version from registry not valid (%s)", packageFromRegistry)
 	}
 
-	return packageName, packageVersion, nil
+	return name, version, nil
 }
 
 func getSystemCommand() *cobra.Command {

internal/compose/compose.go

@@ -114,11 +114,14 @@ func (p *portMapping) UnmarshalYAML(node *yaml.Node) error {
 	}
 
 	// First, parse out the protocol.
-	parts := strings.Split(str, "/")
-	p.Protocol = parts[1]
+	mapping, protocol, found := strings.Cut(str, "/")
+	if !found {
+		return errors.New("could not find protocol in port mapping")
+	}
+	p.Protocol = protocol
 
 	// Now, try to parse out external host, external IP, and internal port.
-	parts = strings.Split(parts[0], ":")
+	parts := strings.Split(mapping, ":")
 	var externalIP, internalPortStr, externalPortStr string
 	switch len(parts) {
 	case 1:

internal/packages/conditions.go

@@ -51,14 +51,14 @@ func parsePackageRequirements(keyValuePairs []string) (*packageRequirements, err
 	var pr packageRequirements
 
 	for _, keyPair := range keyValuePairs {
-		s := strings.SplitN(keyPair, "=", 2)
-		if len(s) != 2 {
+		key, value, valid := strings.Cut(keyPair, "=")
+		if !valid {
 			return nil, fmt.Errorf("invalid key-value pair: %s", keyPair)
 		}
 
-		switch s[0] {
+		switch key {
 		case kibanaVersionRequirement:
-			ver, err := semver.NewVersion(s[1])
+			ver, err := semver.NewVersion(value)
 			if err != nil {
 				return nil, fmt.Errorf("can't parse kibana.version as valid semver: %w", err)
 			}
@@ -73,7 +73,7 @@ func parsePackageRequirements(keyValuePairs []string) (*packageRequirements, err
 			}
 			pr.kibana.version = &withoutPrerelease
 		default:
-			return nil, fmt.Errorf("unknown package requirement: %s", s[0])
+			return nil, fmt.Errorf("unknown package requirement: %s", value)
 		}
 	}
 	return &pr, nil

internal/stack/compose.go

@@ -231,9 +231,9 @@ func newServiceStatus(description *docker.ContainerDescription) (*ServiceStatus,
 }
 
 func getVersionFromDockerImage(dockerImage string) string {
-	fields := strings.Split(dockerImage, ":")
-	if len(fields) == 2 {
-		return fields[1]
+	_, version, found := strings.Cut(dockerImage, ":")
+	if found {
+		return version
 	}
 	return "latest"
 }

internal/stack/parselogs.go

@@ -39,15 +39,12 @@ func ParseLogs(options ParseLogsOptions, process func(log LogLine) error) error
 	for scanner.Scan() {
 		line := scanner.Text()
 
-		messageSlice := strings.SplitN(line, "|", 2)
-
-		if len(messageSlice) != 2 {
+		_, messageLog, valid := strings.Cut(line, "|")
+		if !valid {
 			logger.Debugf("skipped malformed docker-compose log line: %s", line)
 			continue
 		}
 
-		messageLog := messageSlice[1]
-
 		var log LogLine
 		err := json.Unmarshal([]byte(messageLog), &log)
 		if err != nil {

internal/storage/storage.go

@@ -110,14 +110,14 @@ func (prs PackageVersions) Strings() []string {
 func ParsePackageVersions(packageVersions []string) (PackageVersions, error) {
 	var parsed PackageVersions
 	for _, pv := range packageVersions {
-		s := strings.Split(pv, "-")
-		if len(s) != 2 {
+		name, version, valid := strings.Cut(pv, "-")
+		if !valid || name == "" || version == "" {
 			return nil, fmt.Errorf("invalid package revision format (expected: <package_name>-<version>): %s", pv)
 		}
 
-		revision, err := NewPackageVersion(s[0], s[1])
+		revision, err := NewPackageVersion(name, version)
 		if err != nil {
-			return nil, fmt.Errorf("can't create package version (%s): %w", s, err)
+			return nil, fmt.Errorf("can't create package version (name: %s, version: %s): %w", name, version, err)
 		}
 		parsed = append(parsed, *revision)
 	}