refactor: break main into functions (#123)

internal/cmd/cmd.go

@@ -1,7 +1,6 @@
 package cmd
 
 import (
-	"errors"
 	"fmt"
 	"os"
 
@@ -16,27 +15,6 @@ import (
 	"k8s.io/client-go/tools/clientcmd"
 )
 
-func HandleErr(err error) {
-	if err == nil {
-		return
-	}
-
-	pterm.Error.Println(err)
-
-	var errParse *kong.ParseError
-	if errors.As(err, &errParse) {
-		_ = kong.DefaultHelpPrinter(kong.HelpOptions{}, errParse.Context)
-	}
-
-	var e *localerr.LocalError
-	if errors.As(err, &e) {
-		pterm.Println()
-		pterm.Info.Println(e.Help())
-	}
-
-	os.Exit(1)
-}
-
 type verbose bool
 
 func (v verbose) BeforeApply() error {

internal/update/update.go

@@ -6,7 +6,9 @@ import (
 	"errors"
 	"fmt"
 	"net/http"
+	"time"
 
+	"github.com/airbytehq/abctl/internal/build"
 	"golang.org/x/mod/semver"
 )
 
@@ -20,7 +22,13 @@ type doer interface {
 // This is accomplished by fetching the latest github tag and comparing it to the version provided.
 // Returns the latest version, or an empty string if we're already running the latest version.
 // Will return ErrDevVersion if the build.Version is currently set to "dev".
-func Check(ctx context.Context, doer doer, version string) (string, error) {
+func Check(ctx context.Context) (string, error) {
+	ctx, updateCancel := context.WithTimeout(ctx, 2*time.Second)
+	defer updateCancel()
+	return check(ctx, http.DefaultClient, build.Version)
+}
+
+func check(ctx context.Context, doer doer, version string) (string, error) {
 	if version == "dev" {
 		return "", ErrDevVersion
 	}

internal/update/update_test.go

@@ -58,7 +58,7 @@ func TestCheck(t *testing.T) {
 				},
 			}
 
-			latest, err := Check(ctx, h, tt.local)
+			latest, err := check(ctx, h, tt.local)
 			if d := cmp.Diff(tt.wantErr, err, cmpopts.EquateErrors()); d != "" {
 				t.Errorf("unexpected error: %s", err)
 			}
@@ -82,7 +82,7 @@ func TestCheck_HTTPRequest(t *testing.T) {
 		},
 	}
 
-	if _, err := Check(context.Background(), h, "v0.1.0"); err != nil {
+	if _, err := check(context.Background(), h, "v0.1.0"); err != nil {
 		t.Error("unexpected error:", err)
 	}
 	// verify method
@@ -147,7 +147,7 @@ func TestCheck_HTTPErr(t *testing.T) {
 				},
 			}
 
-			_, err := Check(context.Background(), h, "v0.1.0")
+			_, err := check(context.Background(), h, "v0.1.0")
 			if err == nil {
 				t.Error("unexpected success")
 			}

main.go

@@ -3,45 +3,30 @@ package main
 import (
 	"context"
 	"errors"
-	"net/http"
 	"os"
 	"os/signal"
 	"syscall"
-	"time"
 
 	"github.com/airbytehq/abctl/internal/build"
 	"github.com/airbytehq/abctl/internal/cmd"
+	"github.com/airbytehq/abctl/internal/cmd/local/localerr"
 	"github.com/airbytehq/abctl/internal/update"
 	"github.com/alecthomas/kong"
 	"github.com/pterm/pterm"
 )
 
 func main() {
-	ctx, cancel := context.WithCancel(context.Background())
-	defer cancel()
-
-	// check for update
-	updateCtx, updateCancel := context.WithTimeout(ctx, 2*time.Second)
-	defer updateCancel()
-
-	updateChan := make(chan updateInfo)
-	go func() {
-		info := updateInfo{}
-		info.version, info.err = update.Check(updateCtx, http.DefaultClient, build.Version)
-		updateChan <- info
-	}()
+	// ensure the pterm info width matches the other printers
+	pterm.Info.Prefix.Text = " INFO  "
 
-	// listen for shutdown signals
-	go func() {
-		signalCh := make(chan os.Signal, 1)
-		signal.Notify(signalCh, os.Interrupt, syscall.SIGTERM)
-		<-signalCh
+	ctx := cliContext()
+	printUpdateMsg := checkForNewerAbctlVersion(ctx)
+	handleErr(run(ctx))
+	printUpdateMsg()
+}
 
-		cancel()
-	}()
+func run(ctx context.Context) error {
 
-	// ensure the pterm info width matches the other printers
-	pterm.Info.Prefix.Text = " INFO  "
 
 	var root cmd.Cmd
 	parser, err := kong.New(
@@ -51,27 +36,72 @@ func main() {
 		kong.UsageOnError(),
 	)
 	if err != nil {
-		cmd.HandleErr(err)
+		return err
 	}
 	parsed, err := parser.Parse(os.Args[1:])
 	if err != nil {
-		cmd.HandleErr(err)
+		return err
 	}
-	if err := parsed.BindToProvider(bindCtx(ctx)); err != nil {
-		cmd.HandleErr(err)
+	parsed.BindToProvider(bindCtx(ctx))
+	return parsed.Run()
+}
+
+func handleErr(err error) {
+	if err == nil {
+		return
 	}
 
-	cmd.HandleErr(parsed.Run())
+	pterm.Error.Println(err)
 
-	newRelease := <-updateChan
-	if newRelease.err != nil {
-		if errors.Is(newRelease.err, update.ErrDevVersion) {
-			pterm.Debug.Println("Release checking is disabled for dev builds")
-		}
-	} else if newRelease.version != "" {
+	var errParse *kong.ParseError
+	if errors.As(err, &errParse) {
+		_ = kong.DefaultHelpPrinter(kong.HelpOptions{}, errParse.Context)
+	}
+
+	var e *localerr.LocalError
+	if errors.As(err, &e) {
 		pterm.Println()
-		pterm.Info.Printfln("A new release of abctl is available: %s -> %s\nUpdating to the latest version is highly recommended", build.Version, newRelease.version)
+		pterm.Info.Println(e.Help())
 	}
+
+	os.Exit(1)
+}
+
+// checks for a newer version of abctl.
+// returns a function that, when called, will print the message about the new version.
+func checkForNewerAbctlVersion(ctx context.Context) func() {
+	c := make(chan string)
+	go func() {
+		defer close(c)
+		ver, err := update.Check(ctx)
+		if err != nil {
+			pterm.Debug.Printfln("update check: %s", err)
+		} else {
+			c <- ver
+		}
+	}()
+
+	return func() {
+		ver := <-c
+		if ver != "" {
+			pterm.Info.Printfln("A new release of abctl is available: %s -> %s\nUpdating to the latest version is highly recommended", build.Version, ver)
+
+		}
+	}
+}
+
+// get a context that listens for interrupt/shutdown signals.
+func cliContext() context.Context {
+	ctx, cancel := context.WithCancel(context.Background())
+	// listen for shutdown signals
+	go func() {
+		signalCh := make(chan os.Signal, 1)
+		signal.Notify(signalCh, os.Interrupt, syscall.SIGTERM)
+		<-signalCh
+
+		cancel()
+	}()
+	return ctx
 }
 
 // bindCtx exists to allow kong to correctly inject a context.Context into the Run methods on the commands.
@@ -80,8 +110,3 @@ func bindCtx(ctx context.Context) func() (context.Context, error) {
 		return ctx, nil
 	}
 }
-
-type updateInfo struct {
-	version string
-	err     error
-}