chore: add GetValueOrDefault for environment variables (#984)

## Summary

1. Add `GetValueOrDefault` in package `envir`
2. Use the function in `searcher` and `impl`
3. simplify some functions in `initrec` and `plansdk`

## How was it tested?

Author: hezhizhen

internal/envir/util.go

@@ -47,3 +47,14 @@ func IsCI() bool {
 	ci, err := strconv.ParseBool(os.Getenv("CI"))
 	return ci && err == nil
 }
+
+// GetValueOrDefault gets the value of an environment variable.
+// If it's empty, it will return the given default value instead.
+func GetValueOrDefault(key, def string) string {
+	val := os.Getenv(key)
+	if val == "" {
+		val = def
+	}
+
+	return val
+}

internal/impl/devbox.go

@@ -197,10 +197,10 @@ func (d *Devbox) Shell(ctx context.Context) error {
 		return err
 	}
 
-	shellStartTime := os.Getenv(envir.DevboxShellStartTime)
-	if shellStartTime == "" {
-		shellStartTime = telemetry.UnixTimestampFromTime(telemetry.CommandStartTime())
-	}
+	shellStartTime := envir.GetValueOrDefault(
+		envir.DevboxShellStartTime,
+		telemetry.UnixTimestampFromTime(telemetry.CommandStartTime()),
+	)
 
 	opts := []ShellOption{
 		WithHooksFilePath(d.scriptPath(hooksFilename)),

internal/initrec/recommenders/javascript/nodejs.go

@@ -20,8 +20,7 @@ type Recommender struct {
 var _ recommenders.Recommender = (*Recommender)(nil)
 
 func (r *Recommender) IsRelevant() bool {
-	packageJSONPath := filepath.Join(r.SrcDir, "package.json")
-	return fileutil.Exists(packageJSONPath)
+	return fileutil.Exists(filepath.Join(r.SrcDir, "package.json"))
 }
 
 func (r *Recommender) Packages() []string {
@@ -74,8 +73,7 @@ func (r *Recommender) nodeVersion(project *nodeProject) *plansdk.Version {
 }
 
 func (r *Recommender) packageManager() string {
-	yarnPkgLockPath := filepath.Join(r.SrcDir, "yarn.lock")
-	if fileutil.Exists(yarnPkgLockPath) {
+	if fileutil.Exists(filepath.Join(r.SrcDir, "yarn.lock")) {
 		return "yarn"
 	}
 	return "npm"

internal/initrec/recommenders/python/python_poetry.go

@@ -39,7 +39,7 @@ func (r *RecommenderPoetry) Packages() []string {
 // TODO: This can be generalized to all python planners
 func (r *RecommenderPoetry) PythonVersion() *plansdk.Version {
 	defaultVersion, _ := plansdk.NewVersion("3.10.6")
-	project := r.PyProject()
+	project := r.pyProject()
 
 	if project == nil {
 		return defaultVersion
@@ -67,7 +67,7 @@ type pyProject struct {
 	} `toml:"tool"`
 }
 
-func (r *RecommenderPoetry) PyProject() *pyProject {
+func (r *RecommenderPoetry) pyProject() *pyProject {
 	pyProjectPath := filepath.Join(r.SrcDir, "pyproject.toml")
 	content, err := os.ReadFile(pyProjectPath)
 	if err != nil {

internal/initrec/recommenders/ruby/ruby.go

@@ -64,8 +64,6 @@ func parseRubyVersion(gemfile string) string {
 			return matches[2]
 		}
 	}
-	if err := s.Err(); err != nil {
-		return ""
-	}
-	return "" // not found
+
+	return ""
 }

internal/planner/plansdk/version.go

@@ -35,11 +35,7 @@ func (v Version) parts() []string {
 }
 
 func (v Version) Exact() string {
-	parts := v.parts()
-	if len(parts) == 0 {
-		return ""
-	}
-	return strings.Join(parts, "")
+	return strings.Join(v.parts(), "")
 }
 
 func (v Version) Major() string {

internal/searcher/client.go

@@ -9,7 +9,6 @@ import (
 	"io"
 	"net/http"
 	"net/url"
-	"os"
 	"strings"
 
 	"go.jetpack.io/devbox/internal/boxcli/usererr"
@@ -20,11 +19,7 @@ import (
 const searchAPIEndpoint = "https://search.devbox.sh"
 
 func searchHost() string {
-	endpoint := searchAPIEndpoint
-	if os.Getenv(envir.DevboxSearchHost) != "" {
-		endpoint = os.Getenv(envir.DevboxSearchHost)
-	}
-	return endpoint
+	return envir.GetValueOrDefault(envir.DevboxSearchHost, searchAPIEndpoint)
 }
 
 type client struct {

internal/searcher/searcher.go

@@ -9,6 +9,7 @@ import (
 	"strings"
 
 	"github.com/samber/lo"
+
 	"go.jetpack.io/devbox/internal/redact"
 )