Fix nil argument when -P flag is not given

distro/osrelease.go

@@ -46,8 +46,16 @@ type OSRelease struct {
 	Logo             string
 }
 
-// OSReleaseName returns the NAME field of the
+var parsed *OSRelease
+
+// OSReleaseName returns a struct parsed from the system's os-release
+// file. It checks /etc/os-release as well as /usr/lib/os-release.
+// The returned OSRelease struct is a singleton.
 func ParseOSRelease(ctx context.Context) (*OSRelease, error) {
+	if parsed != nil {
+		return parsed, nil
+	}
+
 	fl, err := os.Open("/usr/lib/os-release")
 	if err != nil {
 		fl, err = os.Open("/etc/os-release")
@@ -99,5 +107,6 @@ func ParseOSRelease(ctx context.Context) (*OSRelease, error) {
 		out.Like = strings.Split(runner.Vars["ID_LIKE"].Str, " ")
 	}
 
+	parsed = out
 	return out, nil
 }

internal/overrides/overrides.go

@@ -0,0 +1,92 @@
+package overrides
+
+import (
+	"runtime"
+	"strings"
+
+	"go.arsenm.dev/lure/distro"
+	"go.arsenm.dev/lure/internal/cpu"
+)
+
+type Opts struct {
+	Name        string
+	Overrides   bool
+	LikeDistros bool
+}
+
+var DefaultOpts = &Opts{
+	Overrides:   true,
+	LikeDistros: true,
+}
+
+// Resolve generates a slice of possible override names in the order that they should be checked
+func Resolve(info *distro.OSRelease, opts *Opts) []string {
+	if opts == nil {
+		opts = DefaultOpts
+	}
+
+	if !opts.Overrides {
+		return []string{opts.Name}
+	}
+
+	architectures := []string{runtime.GOARCH}
+
+	if runtime.GOARCH == "arm" {
+		// More specific goes first
+		architectures[0] = cpu.ARMVariant()
+		architectures = append(architectures, "arm")
+	}
+
+	distros := []string{info.ID}
+	if opts.LikeDistros {
+		distros = append(distros, info.Like...)
+	}
+
+	var out []string
+	for _, arch := range architectures {
+		for _, distro := range distros {
+			if opts.Name == "" {
+				out = append(
+					out,
+					arch+"_"+distro,
+					distro,
+				)
+			} else {
+				out = append(
+					out,
+					opts.Name+"_"+arch+"_"+distro,
+					opts.Name+"_"+distro,
+				)
+			}
+		}
+		if opts.Name == "" {
+			out = append(out, arch)
+		} else {
+			out = append(out, opts.Name+"_"+arch)
+		}
+	}
+	if opts.Name != "" {
+		out = append(out, opts.Name)
+	}
+
+	for index, item := range out {
+		out[index] = strings.ReplaceAll(item, "-", "_")
+	}
+
+	return out
+}
+
+func (o *Opts) WithName(name string) *Opts {
+	o.Name = name
+	return o
+}
+
+func (o *Opts) WithOverrides(v bool) *Opts {
+	o.Overrides = v
+	return o
+}
+
+func (o *Opts) WithLikeDistros(v bool) *Opts {
+	o.LikeDistros = v
+	return o
+}

internal/overrides/overrides_test.go

@@ -0,0 +1,86 @@
+package overrides_test
+
+import (
+	"reflect"
+	"testing"
+
+	"go.arsenm.dev/lure/distro"
+	"go.arsenm.dev/lure/internal/overrides"
+)
+
+var info = &distro.OSRelease{
+	ID:   "centos",
+	Like: []string{"rhel", "fedora"},
+}
+
+func TestResolve(t *testing.T) {
+	names := overrides.Resolve(info, nil)
+
+	expected := []string{
+		"amd64_centos",
+		"centos",
+		"amd64_rhel",
+		"rhel",
+		"amd64_fedora",
+		"fedora",
+		"amd64",
+	}
+
+	if !reflect.DeepEqual(names, expected) {
+		t.Errorf("expected %v, got %v", expected, names)
+	}
+}
+
+func TestResolveName(t *testing.T) {
+	names := overrides.Resolve(info, &overrides.Opts{
+		Name:        "deps",
+		Overrides:   true,
+		LikeDistros: true,
+	})
+
+	expected := []string{
+		"deps_amd64_centos",
+		"deps_centos",
+		"deps_amd64_rhel",
+		"deps_rhel",
+		"deps_amd64_fedora",
+		"deps_fedora",
+		"deps_amd64",
+		"deps",
+	}
+
+	if !reflect.DeepEqual(names, expected) {
+		t.Errorf("expected %v, got %v", expected, names)
+	}
+}
+
+func TestResolveNoLikeDistros(t *testing.T) {
+	names := overrides.Resolve(info, &overrides.Opts{
+		Overrides:   true,
+		LikeDistros: false,
+	})
+
+	expected := []string{
+		"amd64_centos",
+		"centos",
+		"amd64",
+	}
+
+	if !reflect.DeepEqual(names, expected) {
+		t.Errorf("expected %v, got %v", expected, names)
+	}
+}
+
+func TestResolveNoOverrides(t *testing.T) {
+	names := overrides.Resolve(info, &overrides.Opts{
+		Name:        "deps",
+		Overrides:   false,
+		LikeDistros: false,
+	})
+
+	expected := []string{"deps"}
+
+	if !reflect.DeepEqual(names, expected) {
+		t.Errorf("expected %v, got %v", expected, names)
+	}
+}

internal/shutils/decoder/decoder.go

@@ -21,14 +21,12 @@ package decoder
 import (
 	"context"
 	"errors"
-	"fmt"
 	"reflect"
-	"runtime"
 	"strings"
 
 	"github.com/mitchellh/mapstructure"
 	"go.arsenm.dev/lure/distro"
-	"go.arsenm.dev/lure/internal/cpu"
+	"go.arsenm.dev/lure/internal/overrides"
 	"golang.org/x/exp/slices"
 	"mvdan.cc/sh/v3/expand"
 	"mvdan.cc/sh/v3/interp"
@@ -169,7 +167,7 @@ func (d *Decoder) GetFunc(name string) (ScriptFunc, bool) {
 }
 
 func (d *Decoder) getFunc(name string) *syntax.Stmt {
-	names := d.genPossibleNames(name)
+	names := overrides.Resolve(d.info, overrides.DefaultOpts.WithName(name))
 	for _, fnName := range names {
 		fn, ok := d.runner.Funcs[fnName]
 		if ok {
@@ -182,7 +180,7 @@ func (d *Decoder) getFunc(name string) *syntax.Stmt {
 // getVar gets a variable based on its name, taking into account
 // override variables and nameref variables.
 func (d *Decoder) getVar(name string) *expand.Variable {
-	names := d.genPossibleNames(name)
+	names := overrides.Resolve(d.info, overrides.DefaultOpts.WithName(name))
 	for _, varName := range names {
 		val, ok := d.runner.Vars[varName]
 		if ok {
@@ -200,43 +198,3 @@ func (d *Decoder) getVar(name string) *expand.Variable {
 	}
 	return nil
 }
-
-// genPossibleNames generates a slice of the possible names that
-// could be used in the order that they should be checked
-func (d *Decoder) genPossibleNames(name string) []string {
-	if !d.Overrides {
-		return []string{name}
-	}
-
-	architectures := []string{runtime.GOARCH}
-
-	if runtime.GOARCH == "arm" {
-		// More specific goes first
-		architectures[0] = cpu.ARMVariant()
-		architectures = append(architectures, "arm")
-	}
-
-	distros := []string{d.info.ID}
-	if d.LikeDistros {
-		distros = append(distros, d.info.Like...)
-	}
-
-	var out []string
-	for _, arch := range architectures {
-		for _, distro := range distros {
-			out = append(
-				out,
-				fmt.Sprintf("%s_%s_%s", name, arch, distro),
-				fmt.Sprintf("%s_%s", name, distro),
-			)
-		}
-		out = append(out, fmt.Sprintf("%s_%s", name, arch))
-	}
-	out = append(out, name)
-
-	for index, item := range out {
-		out[index] = strings.ReplaceAll(item, "-", "_")
-	}
-
-	return out
-}

main.go

@@ -166,6 +166,10 @@ func main() {
 		},
 		Before: func(c *cli.Context) error {
 			args := strings.Split(c.String("pm-args"), " ")
+			if len(args) == 1 && args[0] == "" {
+				args = nil
+			}
+
 			manager.Args = append(manager.Args, args...)
 			return nil
 		},