[devtools] [help] Warn user when game is run outside the module directory

When game is run outside the module directory then help command does not work for all symbols from pi module.

Author: elgopher

devtools/internal/help/help.go

@@ -15,7 +15,10 @@ import (
 	"github.com/elgopher/pi/devtools/internal/lib"
 )
 
-var NotFound = fmt.Errorf("no help found")
+var (
+	NotFound     = fmt.Errorf("no help found")
+	NotAvailable = fmt.Errorf("help for pi module not available outside Go module using Pi")
+)
 
 func PrintHelp(topic string) error {
 	switch topic {
@@ -66,6 +69,9 @@ func goDoc(symbol string) error {
 	if err := command.Run(); err != nil {
 		var exitErr *exec.ExitError
 		if isExitErr := errors.As(err, &exitErr); isExitErr && exitErr.ExitCode() == 1 {
+			if strings.HasPrefix(symbol, "github.com/elgopher/pi") && moduleDoesNotHaveDependencyToPi() {
+				return NotAvailable
+			}
 			return NotFound
 		}
 
@@ -75,6 +81,12 @@ func goDoc(symbol string) error {
 	return nil
 }
 
+func moduleDoesNotHaveDependencyToPi() bool {
+	cmd := exec.Command("go", "list", "-m", "github.com/elgopher/pi")
+	err := cmd.Run()
+	return err != nil
+}
+
 func completeSymbol(symbol string) string {
 	packages := lib.AllPackages()
 

devtools/internal/help/help_test.go

@@ -6,9 +6,11 @@
 package help_test
 
 import (
+	"os"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 
 	"github.com/elgopher/pi/devtools/internal/help"
 	"github.com/elgopher/pi/devtools/internal/test"
@@ -103,4 +105,25 @@ func TestPrintHelp(t *testing.T) {
 			})
 		}
 	})
+
+	t.Run("should return error when help is not available because game was run outside the module using Pi", func(t *testing.T) {
+		prevWorkDir, err := os.Getwd()
+		require.NoError(t, err)
+
+		tmpDir, err := os.MkdirTemp("", "")
+		require.NoError(t, err)
+		defer func() {
+			_ = os.RemoveAll(tmpDir)
+		}()
+
+		err = os.Chdir(tmpDir)
+		require.NoError(t, err)
+		defer func() {
+			_ = os.Chdir(prevWorkDir)
+		}()
+		// when
+		err = help.PrintHelp("pi.Spr")
+		// then
+		assert.ErrorIs(t, err, help.NotAvailable)
+	})
 }

devtools/scripting.go

@@ -54,7 +54,12 @@ func evaluateNextCommandFromTerminal() {
 	case cmd := <-terminal.Commands:
 		result, err := interpreterInstance.Eval(cmd)
 		if err != nil {
-			fmt.Println(err)
+			switch err {
+			case help.NotAvailable:
+				fmt.Println("Sorry, help for pi module is only available when the game has been started in the directory of the Go module that uses the Pi.")
+			default:
+				fmt.Println(err)
+			}
 			terminal.CommandsProcessed <- terminal.Done
 
 			return