[plugins] Join hash -r and source message and show in yellow (#452)

## Summary

This improves the message we show when a package that has env vars is
installed. It shows it in yellow at the very end always. It also joins
the `hash -r` command so that it's a single command.

This is a stopgap until we have a better way to use update env variables
while in shell. Once that is done, some of this change can be reverted.
(we might also be able to remove the need for `hash -r` command by
running it directly from devbox and/or only showing it when it actually
needs to be run)

I also considered creating a global env file that sources all the env
files but this would cause potential overwriting I didn't want.

## How was it tested?

<img width="595" alt="image"
src="https://user-images.githubusercontent.com/544948/211695932-63e628e4-3cb9-42a2-aab3-aed933930597.png">

Author: mikeland73

internal/impl/devbox.go

@@ -164,7 +164,6 @@ func (d *Devbox) Add(pkgs ...string) error {
 				pkg,
 				d.projectDir,
 				d.writer,
-				IsDevboxShellEnabled(),
 				false, /*markdown*/
 			); err != nil {
 				return err
@@ -423,7 +422,6 @@ func (d *Devbox) Info(pkg string, markdown bool) error {
 		pkg,
 		d.projectDir,
 		d.writer,
-		false, /*showSourceEnv*/
 		markdown,
 	)
 }
@@ -605,7 +603,7 @@ func (d *Devbox) printPackageUpdateMessage(
 
 	if len(pkgs) > 0 {
 
-		successMsg := fmt.Sprintf("%s (%s) is now %s.", pkgs[0], infos[0], verb)
+		successMsg := fmt.Sprintf("%s (%s) is now %s.\n", pkgs[0], infos[0], verb)
 		if len(pkgs) > 1 {
 			pkgsWithVersion := []string{}
 			for idx, pkg := range pkgs {
@@ -622,13 +620,18 @@ func (d *Devbox) printPackageUpdateMessage(
 		}
 		fmt.Fprint(d.writer, successMsg)
 
-		// (Only when in devbox shell) Prompt the user to run `hash -r` to ensure
-		// their shell can access the most recently installed binaries, or ensure
-		// their recently uninstalled binaries are not accidentally still available.
-		if !IsDevboxShellEnabled() {
-			fmt.Fprintln(d.writer)
-		} else {
-			fmt.Fprintln(d.writer, " Run `hash -r` to ensure your shell is updated.")
+		fmt.Fprintln(d.writer)
+
+		// (Only when in devbox shell) Prompt the user to run hash -r
+		// to ensure we refresh the shell hash and load the proper environment.
+		if IsDevboxShellEnabled() {
+			if err := plugin.PrintEnvUpdateMessage(
+				lo.Ternary(mode == install, pkgs, []string{}),
+				d.projectDir,
+				d.writer,
+			); err != nil {
+				return err
+			}
 		}
 	} else {
 		fmt.Fprintf(d.writer, "No packages %s.\n", verb)

internal/plugin/info.go

@@ -3,15 +3,19 @@ package plugin
 import (
 	"fmt"
 	"io"
+	"os"
+	"path/filepath"
+	"strings"
 
+	"github.com/fatih/color"
 	"github.com/pkg/errors"
 	"github.com/samber/lo"
 )
 
 func PrintReadme(
 	pkg, projectDir string,
 	w io.Writer,
-	showSourceEnv, markdown bool,
+	markdown bool,
 ) error {
 	cfg, err := getConfigIfAny(pkg, projectDir)
 
@@ -45,9 +49,6 @@ func PrintReadme(
 		return err
 	}
 
-	if showSourceEnv {
-		err = printSourceEnvMessage(pkg, projectDir, w)
-	}
 	return err
 }
 
@@ -132,18 +133,26 @@ func printInfoInstructions(pkg string, w io.Writer) error {
 	return errors.WithStack(err)
 }
 
-func printSourceEnvMessage(pkg, projectDir string, w io.Writer) error {
-	env, err := Env([]string{pkg}, projectDir)
-	if err != nil {
-		return err
+func PrintEnvUpdateMessage(pkgs []string, projectDir string, w io.Writer) error {
+	commands := []string{"hash -r"}
+	for _, pkg := range pkgs {
+		if path := getEnvFilePathIfExist(pkg, projectDir); path != "" {
+			wd, err := os.Getwd()
+			if err != nil {
+				return errors.WithStack(err)
+			}
+			relPath, err := filepath.Rel(wd, path)
+			if err != nil {
+				return errors.WithStack(err)
+			}
+			commands = append(commands, fmt.Sprintf("source %s", relPath))
+		}
 	}
-	if len(env) > 0 {
-		_, err = fmt.Fprintf(
+	color.New(color.FgYellow).
+		Fprintf(
 			w,
-			"To ensure environment is set, run `source %s/%s/env`\n\n",
-			VirtenvPath,
-			pkg,
+			"Run `%s` to ensure your shell is updated.\n\n",
+			strings.Join(commands, " && "),
 		)
-	}
-	return errors.WithStack(err)
+	return nil
 }

internal/plugin/pkgcfg.go

@@ -120,6 +120,14 @@ func Env(pkgs []string, projectDir string) (map[string]string, error) {
 	return env, nil
 }
 
+func getEnvFilePathIfExist(pkg, projectDir string) string {
+	filePath := filepath.Join(projectDir, VirtenvPath, pkg, "/env")
+	if _, err := os.Stat(filePath); err != nil {
+		return ""
+	}
+	return filePath
+}
+
 func createEnvFile(pkg, projectDir string) error {
 	envVars, err := Env([]string{pkg}, projectDir)
 	if err != nil {