🐛 fix(driver): improve Go PATH detection for optional driver builds

internal/app/methods_driver_test.go

@@ -0,0 +1,156 @@
+package app
+
+import (
+	"os"
+	"os/exec"
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestCandidateShellsForCommandLookup_DedupesAndPreservesOrder(t *testing.T) {
+	originalShell := os.Getenv("SHELL")
+	t.Cleanup(func() {
+		_ = os.Setenv("SHELL", originalShell)
+	})
+	if err := os.Setenv("SHELL", "/bin/zsh"); err != nil {
+		t.Fatalf("set SHELL: %v", err)
+	}
+
+	got := candidateShellsForCommandLookup()
+	want := []string{"/bin/zsh", "/bin/bash", "/bin/sh"}
+	if len(got) != len(want) {
+		t.Fatalf("unexpected shell count: got %v want %v", got, want)
+	}
+	for i := range want {
+		if got[i] != want[i] {
+			t.Fatalf("unexpected shell order: got %v want %v", got, want)
+		}
+	}
+}
+
+func TestResolveGoBinaryPath_FallsBackToKnownLocation(t *testing.T) {
+	originalLookPath := goBinaryLookPath
+	originalStat := goBinaryStat
+	originalCommand := goBinaryCommand
+	t.Cleanup(func() {
+		goBinaryLookPath = originalLookPath
+		goBinaryStat = originalStat
+		goBinaryCommand = originalCommand
+	})
+
+	goBinaryLookPath = func(file string) (string, error) {
+		return "", exec.ErrNotFound
+	}
+	goBinaryStat = func(name string) (os.FileInfo, error) {
+		if name == "/opt/homebrew/bin/go" {
+			return fakeFileInfo{name: "go"}, nil
+		}
+		return nil, os.ErrNotExist
+	}
+	goBinaryCommand = func(name string, arg ...string) *exec.Cmd {
+		t.Fatalf("shell fallback should not run when common path exists")
+		return nil
+	}
+
+	got, err := resolveGoBinaryPath()
+	if err != nil {
+		t.Fatalf("resolveGoBinaryPath returned error: %v", err)
+	}
+	if got != "/opt/homebrew/bin/go" {
+		t.Fatalf("unexpected go path: %s", got)
+	}
+}
+
+func TestResolveGoBinaryPath_FallsBackToShellOutput(t *testing.T) {
+	originalLookPath := goBinaryLookPath
+	originalStat := goBinaryStat
+	originalCommand := goBinaryCommand
+	originalShell := os.Getenv("SHELL")
+	t.Cleanup(func() {
+		goBinaryLookPath = originalLookPath
+		goBinaryStat = originalStat
+		goBinaryCommand = originalCommand
+		_ = os.Setenv("SHELL", originalShell)
+	})
+	if err := os.Setenv("SHELL", "/custom/shell"); err != nil {
+		t.Fatalf("set SHELL: %v", err)
+	}
+
+	goBinaryLookPath = func(file string) (string, error) {
+		return "", exec.ErrNotFound
+	}
+	goBinaryStat = func(name string) (os.FileInfo, error) {
+		if name == "/Users/test/go/bin/go" {
+			return fakeFileInfo{name: "go"}, nil
+		}
+		return nil, os.ErrNotExist
+	}
+	var called []string
+	goBinaryCommand = func(name string, arg ...string) *exec.Cmd {
+		called = append(called, name)
+		if len(called) == 1 {
+			return exec.Command("/bin/sh", "-c", "printf 'welcome\\n/Users/test/go/bin/go\\n'")
+		}
+		return exec.Command("/bin/sh", "-c", "exit 1")
+	}
+
+	got, err := resolveGoBinaryPath()
+	if err != nil {
+		t.Fatalf("resolveGoBinaryPath returned error: %v", err)
+	}
+	if got != "/Users/test/go/bin/go" {
+		t.Fatalf("unexpected go path from shell fallback: %s", got)
+	}
+	if len(called) == 0 || called[0] != "/custom/shell" {
+		t.Fatalf("expected shell lookup to start with SHELL env, got %v", called)
+	}
+}
+
+func TestResolveExistingPathFromCommandOutput_SkipsNoiseLines(t *testing.T) {
+	originalStat := goBinaryStat
+	t.Cleanup(func() {
+		goBinaryStat = originalStat
+	})
+	goBinaryStat = func(name string) (os.FileInfo, error) {
+		if name == "/opt/homebrew/bin/go" {
+			return fakeFileInfo{name: "go"}, nil
+		}
+		return nil, os.ErrNotExist
+	}
+
+	got := resolveExistingPathFromCommandOutput([]byte("\n notice \n /opt/homebrew/bin/go \n /usr/local/bin/go \n"))
+	if got != "/opt/homebrew/bin/go" {
+		t.Fatalf("unexpected parsed path: %q", got)
+	}
+}
+
+type fakeFileInfo struct {
+	name string
+}
+
+func (f fakeFileInfo) Name() string       { return f.name }
+func (f fakeFileInfo) Size() int64        { return 0 }
+func (f fakeFileInfo) Mode() os.FileMode  { return 0o755 }
+func (f fakeFileInfo) ModTime() time.Time { return time.Time{} }
+func (f fakeFileInfo) IsDir() bool        { return false }
+func (f fakeFileInfo) Sys() any           { return nil }
+
+func TestCandidateShellsForCommandLookup_IgnoresBlankShell(t *testing.T) {
+	originalShell := os.Getenv("SHELL")
+	t.Cleanup(func() {
+		_ = os.Setenv("SHELL", originalShell)
+	})
+	if err := os.Setenv("SHELL", "   "); err != nil {
+		t.Fatalf("set SHELL: %v", err)
+	}
+
+	got := candidateShellsForCommandLookup()
+	joined := strings.Join(got, ",")
+	if strings.Contains(joined, "  ") {
+		t.Fatalf("expected blank shell to be ignored: %v", got)
+	}
+	if len(got) != 3 {
+		t.Fatalf("unexpected shell list: %v", got)
+	}
+}