fix: improve gpg.program detection, add more tests

Signed-off-by: Carlos A Becker <caarlos0@users.noreply.github.com>

internal/pipe/git/git.go

@@ -339,13 +339,13 @@ func getFromEnv(s string) func() ([]string, error) {
 }
 
 // GetGPGProgram returns the user set GPG path or "gpg" if nothing is set
-func GetGPGProgram(ctx *context.Context) (string, error) {
-	path, err := git.Clean(git.Run(ctx, "config", "gpg.program"))
+func GetGPGProgram(ctx *context.Context) string {
+	path, _ := git.Clean(git.Run(ctx, "config", "gpg.program"))
 
 	// if config not set assume default
 	if len(path) == 0 {
 		path = "gpg"
 	}
 
-	return path, err
+	return path
 }

internal/pipe/sign/sign.go

@@ -12,10 +12,10 @@ import (
 	"github.com/caarlos0/log"
 	"github.com/goreleaser/goreleaser/internal/artifact"
 	"github.com/goreleaser/goreleaser/internal/gio"
+	"github.com/goreleaser/goreleaser/internal/git"
 	"github.com/goreleaser/goreleaser/internal/ids"
 	"github.com/goreleaser/goreleaser/internal/logext"
 	"github.com/goreleaser/goreleaser/internal/pipe"
-	"github.com/goreleaser/goreleaser/internal/pipe/git"
 	"github.com/goreleaser/goreleaser/internal/semerrgroup"
 	"github.com/goreleaser/goreleaser/internal/tmpl"
 	"github.com/goreleaser/goreleaser/pkg/config"
@@ -36,11 +36,13 @@ func (Pipe) Dependencies(ctx *context.Context) []string {
 	return cmds
 }
 
+const defaultGpg = "gpg"
+
 // Default sets the Pipes defaults.
 func (Pipe) Default(ctx *context.Context) error {
-	gpgPath, err := git.GetGPGProgram(ctx)
-	if err != nil {
-		return err
+	gpgPath, _ := git.Clean(git.Run(ctx, "config", "gpg.program"))
+	if gpgPath == "" {
+		gpgPath = defaultGpg
 	}
 
 	ids := ids.New("signs")

internal/pipe/sign/sign_test.go

@@ -15,7 +15,9 @@ import (
 	"github.com/stretchr/testify/assert"
 
 	"github.com/goreleaser/goreleaser/internal/artifact"
+	"github.com/goreleaser/goreleaser/internal/git"
 	"github.com/goreleaser/goreleaser/internal/testctx"
+	"github.com/goreleaser/goreleaser/internal/testlib"
 	"github.com/goreleaser/goreleaser/pkg/config"
 	"github.com/goreleaser/goreleaser/pkg/context"
 	"github.com/stretchr/testify/require"
@@ -51,17 +53,34 @@ func TestDescription(t *testing.T) {
 }
 
 func TestSignDefault(t *testing.T) {
+	_ = testlib.Mktmp(t)
+	testlib.GitInit(t)
+
 	ctx := testctx.NewWithCfg(config.Project{
 		Signs: []config.Sign{{}},
 	})
-	err := Pipe{}.Default(ctx)
-	require.NoError(t, err)
-	require.Equal(t, ctx.Config.Signs[0].Cmd, "gpg") // assumes git config gpg.program is not set
+	setGpg(t, ctx, "") // force empty gpg.program
+
+	require.NoError(t, Pipe{}.Default(ctx))
+	require.Equal(t, ctx.Config.Signs[0].Cmd, "gpg")
 	require.Equal(t, ctx.Config.Signs[0].Signature, "${artifact}.sig")
 	require.Equal(t, ctx.Config.Signs[0].Args, []string{"--output", "$signature", "--detach-sig", "$artifact"})
 	require.Equal(t, ctx.Config.Signs[0].Artifacts, "none")
 }
 
+func TestDefaultGpgFromGitConfig(t *testing.T) {
+	_ = testlib.Mktmp(t)
+	testlib.GitInit(t)
+
+	ctx := testctx.NewWithCfg(config.Project{
+		Signs: []config.Sign{{}},
+	})
+	setGpg(t, ctx, "not-really-gpg")
+
+	require.NoError(t, Pipe{}.Default(ctx))
+	require.Equal(t, ctx.Config.Signs[0].Cmd, "not-really-gpg")
+}
+
 func TestSignDisabled(t *testing.T) {
 	ctx := testctx.NewWithCfg(config.Project{Signs: []config.Sign{{Artifacts: "none"}}})
 	err := Pipe{}.Run(ctx)
@@ -740,3 +759,9 @@ func TestDependencies(t *testing.T) {
 	})
 	require.Equal(t, []string{"cosign", "gpg2"}, Pipe{}.Dependencies(ctx))
 }
+
+func setGpg(tb testing.TB, ctx *context.Context, p string) {
+	tb.Helper()
+	_, err := git.Run(ctx, "config", "--local", "--add", "gpg.program", p)
+	require.NoError(tb, err)
+}