verify that the main application container works properly

CHANGELOG.md

@@ -7,6 +7,7 @@ and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.
 ## [Unreleased]
 - Refactored Switch into a simpler interface that removes internal concurrency
 - Ensure that as much as possible test logging goes through testing.T
+- Added tests for the main DI container
 
 ## [v0.1.0]
 - README text

main.go

@@ -7,24 +7,22 @@ import (
 	"go.uber.org/fx"
 )
 
-func run(args []string) error {
-	app := fx.New(
+func newApp(args []string) *fx.App {
+	return fx.New(
 		parseCommandLine(args),
 		provideLogger(os.Stdout),
 		provideActions(),
 		provideSwitchConfig(),
 		provideSwitch(),
 		provideHTTP(),
 	)
-
-	app.Run()
-	return app.Err()
 }
 
 func main() {
-	err := run(os.Args[1:])
-	if err != nil {
-		fmt.Fprintf(os.Stderr, "%s\n", err)
+	app := newApp(os.Args[1:])
+	app.Run()
+	if app.Err() != nil {
+		fmt.Fprintf(os.Stderr, "%s\n", app.Err())
 		os.Exit(1)
 	}
 }

main_test.go

@@ -0,0 +1,55 @@
+package main
+
+import (
+	"strconv"
+	"testing"
+
+	"github.com/stretchr/testify/suite"
+)
+
+type NewAppSuite struct {
+	DMSSuite
+
+	validParameters   [][]string
+	invalidParameters [][]string
+}
+
+func (suite *NewAppSuite) SetupSuite() {
+	suite.validParameters = [][]string{
+		{"--exec", "echo 'hi'"},
+		{"--exec", "echo 'hi'", "--ttl", "10s", "--misses", "4"},
+		{"--exec", "echo 'hi'", "--exec", "echo 'another'", "--ttl", "12h", "--misses", "2", "--debug"},
+	}
+
+	suite.invalidParameters = [][]string{
+		{},
+		{"--foobar"},
+		{"--exec", "echo 'hi'", "--foobar"},
+	}
+}
+
+func (suite *NewAppSuite) TestNewApp() {
+	suite.Run("Valid", func() {
+		for i, validParameters := range suite.validParameters {
+			suite.Run(strconv.Itoa(i), func() {
+				app := newApp(validParameters)
+				suite.Require().NotNil(app)
+				suite.NoError(app.Err())
+			})
+		}
+	})
+
+	suite.Run("Invalid", func() {
+		for i, invalidParameters := range suite.invalidParameters {
+			suite.Run(strconv.Itoa(i), func() {
+				app := newApp(invalidParameters)
+				suite.Require().NotNil(app)
+				suite.Error(app.Err())
+			})
+		}
+	})
+}
+
+func TestNewApp(t *testing.T) {
+	suite.Run(t, new(NewAppSuite))
+}