[WIP] Fix error return bug and some minor code style (temporalio#4234)

* Fix error return bug and some minor code style

* Add unit tests

* Update error formatting

tools/cassandra/handler.go

@@ -25,6 +25,7 @@
 package cassandra
 
 import (
+	"fmt"
 	"strings"
 
 	"github.com/urfave/cli"
@@ -96,7 +97,8 @@ func createKeyspace(cli *cli.Context, logger log.Logger) error {
 	}
 	keyspace := cli.String(schema.CLIOptKeyspace)
 	if keyspace == "" {
-		logger.Error("Unable to read config.", tag.Error(schema.NewConfigError("missing "+flag(schema.CLIOptKeyspace)+" argument ")))
+		err := fmt.Errorf("missing %s argument", flag(schema.CLIOptKeyspace))
+		logger.Error("Unable to read config.", tag.Error(schema.NewConfigError(err.Error())))
 		return err
 	}
 	err = doCreateKeyspace(config, keyspace, logger)
@@ -115,7 +117,8 @@ func dropKeyspace(cli *cli.Context, logger log.Logger) error {
 	}
 	keyspace := cli.String(schema.CLIOptKeyspace)
 	if keyspace == "" {
-		logger.Error("Unable to read config.", tag.Error(schema.NewConfigError("missing "+flag(schema.CLIOptKeyspace)+" argument ")))
+		err := fmt.Errorf("missing %s argument", flag(schema.CLIOptKeyspace))
+		logger.Error("Unable to read config.", tag.Error(schema.NewConfigError(err.Error())))
 		return err
 	}
 	err = doDropKeyspace(config, keyspace, logger)
@@ -161,12 +164,8 @@ func doDropKeyspace(cfg *CQLClientConfig, name string, logger log.Logger) error
 	if err != nil {
 		return err
 	}
-	err = client.dropKeyspace(name)
-	if err != nil {
-		return err
-	}
-	client.Close()
-	return nil
+	defer client.Close()
+	return client.dropKeyspace(name)
 }
 
 func newCQLClientConfig(cli *cli.Context) (*CQLClientConfig, error) {

tools/cassandra/handler_test.go

@@ -71,3 +71,29 @@ func (s *HandlerTestSuite) TestParsingOfOptionsMap() {
 
 	s.Assert().Equal(0, len(parsedMap2))
 }
+
+func (s *HandlerTestSuite) TestDropKeyspaceError() {
+	// fake exit function to avoid exiting the application
+	back := osExit
+	defer func() { osExit = back }()
+	osExit = func(i int) {
+		s.Equal(1, i)
+	}
+	args := []string{"./tool", "drop-keyspace", "-f", "--keyspace", ""}
+	app := buildCLIOptions()
+	err := app.Run(args)
+	s.Nil(err)
+}
+
+func (s *HandlerTestSuite) TestCreateKeyspaceError() {
+	// fake exit function to avoid exiting the application
+	back := osExit
+	defer func() { osExit = back }()
+	osExit = func(i int) {
+		s.Equal(1, i)
+	}
+	args := []string{"./tool", "create-keyspace", "--keyspace", ""}
+	app := buildCLIOptions()
+	err := app.Run(args)
+	s.Nil(err)
+}

tools/cassandra/main.go

@@ -41,12 +41,14 @@ func RunTool(args []string) error {
 	return app.Run(args)
 }
 
+var osExit = os.Exit
+
 // root handler for all cli commands
 func cliHandler(c *cli.Context, handler func(c *cli.Context, logger log.Logger) error, logger log.Logger) {
 	quiet := c.GlobalBool(schema.CLIOptQuiet)
 	err := handler(c, logger)
 	if err != nil && !quiet {
-		os.Exit(1)
+		osExit(1)
 	}
 }