make it clear that a function has a side effect

bosh/client.go

@@ -51,7 +51,7 @@ func New(config config.ConfigView, outputs terraform.Outputs, stdout, stderr io.
 		return nil, err
 	}
 
-	boshCLIPath, err := resource.BOSHCLIPath()
+	boshCLIPath, err := resource.DownloadBOSHCLI()
 	if err != nil {
 		return nil, fmt.Errorf("failed to determine BOSH CLI path: [%v]", err)
 	}

resource/package.go

@@ -124,14 +124,14 @@ func (p binaryPaths) path() string {
 	}
 }
 
-// BOSHCLIPath returns the path of the downloaded bosh-cli
-func BOSHCLIPath() (string, error) {
+// DownloadBOSHCLI returns the path of the downloaded bosh-cli
+func DownloadBOSHCLI() (string, error) {
 	p := binaries["bosh-cli"].path()
 	return bincache.Download(p)
 }
 
-// TerraformCLIPath returns the path of the downloaded terraform-cli
-func TerraformCLIPath() (string, error) {
+// DownloadTerraformCLI returns the path of the downloaded terraform-cli
+func DownloadTerraformCLI() (string, error) {
 	p := binaries["terraform"].path()
 	return bincache.Download(p)
 }

terraform/terraform.go

@@ -67,7 +67,7 @@ func Path(path string) Option {
 // DownloadTerraform returns the dowloaded CLI path Option
 func DownloadTerraform() Option {
 	return func(c *CLI) error {
-		path, err := resource.TerraformCLIPath()
+		path, err := resource.DownloadTerraformCLI()
 		c.Path = path
 		return err
 	}