refactor: os checks (#350)

Replaces string literals for OS checks with predefined constants for improved maintainability and consistency.

Signed-off-by: Ryan Johnson <ryan.johnson@broadcom.com>

Author: tenthirtyam

builder/vmware/common/driver.go

@@ -283,13 +283,13 @@ func NewDriver(dconfig *DriverConfig, config *SSHConfig, vmName string) (Driver,
 
 	} else {
 		switch runtime.GOOS {
-		case "darwin":
+		case osMacOS:
 			drivers = []Driver{
 				NewFusionDriver(dconfig, config),
 			}
-		case "linux":
+		case osLinux:
 			fallthrough
-		case "windows":
+		case osWindows:
 			drivers = []Driver{
 				NewWorkstationDriver(config),
 			}
@@ -589,7 +589,7 @@ func (d *VmwareDriver) PotentialGuestIP(state multistep.StateBag) ([]string, err
 		return addrs, nil
 	}
 
-	if runtime.GOOS == "darwin" {
+	if runtime.GOOS == osMacOS {
 		// We have match no vmware DHCP lease for this MAC. We'll try to match it in Apple DHCP leases.
 		// As a remember, VMware is no longer able to rely on its own dhcpd server on MacOS BigSur and is
 		// forced to use Apple DHCPD server instead.

builder/vmware/common/driver_workstation.go

@@ -261,7 +261,7 @@ func (d *WorkstationDriver) Verify() error {
 
 		// For non-Windows, if neither the default nor alternate configuration
 		// paths exist, return an error.
-		if err != nil && runtime.GOOS != "windows" {
+		if err != nil && runtime.GOOS != osWindows {
 			return nil, err
 		}
 

builder/vmware/common/driver_workstation_unix.go

@@ -139,7 +139,7 @@ func workstationNetmapConfPath() string {
 // workstationVerifyVersion verifies the VMware Workstation version against the
 // required version using workstationTestVersion.
 func workstationVerifyVersion(version string) error {
-	if runtime.GOOS != "linux" {
+	if runtime.GOOS != osLinux {
 		return fmt.Errorf("driver is only supported on Linux, not %s", runtime.GOOS)
 	}
 

builder/vmware/common/hw_config.go

@@ -269,7 +269,7 @@ func (c *HWConfig) HasSerial() bool {
 
 func (c *HWConfig) ReadSerial() (*SerialUnion, error) {
 	var defaultSerialPort string
-	if runtime.GOOS == "windows" {
+	if runtime.GOOS == osWindows {
 		defaultSerialPort = "COM1"
 	} else {
 		defaultSerialPort = "/dev/ttyS0"

builder/vmware/common/tools_config_test.go

@@ -57,7 +57,7 @@ func TestToolsConfigPrepare_SourceSuccess(t *testing.T) {
 		},
 		{
 			ToolsSourcePath:   "path/to/tools.iso",
-			ToolsUploadFlavor: "linux",
+			ToolsUploadFlavor: osLinux,
 		},
 	} {
 		errs := c.Prepare(interpolate.NewContext())