refactor: making it easier to merge with pro (#3463)

this improves mergeability between pro and oss a bit

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

internal/git/git.go

@@ -59,3 +59,19 @@ func Clean(output string, err error) (string, error) {
 	}
 	return output, err
 }
+
+// CleanAllLines returns all the non empty lines of the output, cleaned up.
+func CleanAllLines(output string, err error) ([]string, error) {
+	var result []string
+	for _, line := range strings.Split(output, "\n") {
+		l := strings.TrimSpace(strings.ReplaceAll(line, "'", ""))
+		if l == "" {
+			continue
+		}
+		result = append(result, l)
+	}
+	if err != nil {
+		err = errors.New(strings.TrimSuffix(err.Error(), "\n"))
+	}
+	return result, err
+}

internal/git/git_test.go

@@ -36,10 +36,15 @@ func TestGitWarning(t *testing.T) {
 	testlib.GitCommit(t, "foobar")
 	testlib.GitBranch(t, "tags/1.2.3")
 	testlib.GitTag(t, "1.2.3")
+	testlib.GitTag(t, "nightly")
 
 	out, err := git.Run(ctx, "describe", "--tags", "--abbrev=0", "tags/1.2.3^")
 	require.NoError(t, err)
 	require.Equal(t, "1.2.2\n", out)
+
+	tags, err := git.CleanAllLines(git.Run(ctx, "tag", "--points-at", "HEAD", "--sort", "-version:refname"))
+	require.NoError(t, err)
+	require.ElementsMatch(t, []string{"1.2.3", "nightly"}, tags)
 }
 
 func TestRepo(t *testing.T) {
@@ -52,16 +57,32 @@ func TestRepo(t *testing.T) {
 
 func TestClean(t *testing.T) {
 	ctx := context.Background()
-	out, err := git.Clean("asdasd 'ssadas'\nadasd", nil)
-	require.NoError(t, err)
-	require.Equal(t, "asdasd ssadas", out)
 
-	out, err = git.Clean(git.Run(ctx, "command-that-dont-exist"))
-	require.Error(t, err)
-	require.Empty(t, out)
-	require.Equal(
-		t,
-		"git: 'command-that-dont-exist' is not a git command. See 'git --help'.",
-		err.Error(),
-	)
+	t.Run("success", func(t *testing.T) {
+		out, err := git.Clean("asdasd 'ssadas'\nadasd", nil)
+		require.NoError(t, err)
+		require.Equal(t, "asdasd ssadas", out)
+	})
+
+	t.Run("error", func(t *testing.T) {
+		out, err := git.Clean(git.Run(ctx, "command-that-dont-exist"))
+		require.Error(t, err)
+		require.Empty(t, out)
+		require.Equal(
+			t,
+			"git: 'command-that-dont-exist' is not a git command. See 'git --help'.",
+			err.Error(),
+		)
+	})
+
+	t.Run("all lines error", func(t *testing.T) {
+		out, err := git.CleanAllLines(git.Run(ctx, "command-that-dont-exist"))
+		require.Error(t, err)
+		require.Empty(t, out)
+		require.Equal(
+			t,
+			"git: 'command-that-dont-exist' is not a git command. See 'git --help'.",
+			err.Error(),
+		)
+	})
 }

internal/pipe/git/git.go

@@ -222,36 +222,90 @@ func getTagWithFormat(ctx *context.Context, tag, format string) (string, error)
 }
 
 func getTag(ctx *context.Context) (string, error) {
-	var tag string
-	var err error
-	for _, fn := range []func() (string, error){
-		func() (string, error) {
-			return os.Getenv("GORELEASER_CURRENT_TAG"), nil
+	for _, fn := range []func() ([]string, error){
+		getFromEnv("GORELEASER_CURRENT_TAG"),
+		func() ([]string, error) {
+			return gitTagsPointingAt(ctx, "HEAD")
 		},
-		func() (string, error) {
-			return git.Clean(git.Run(ctx, "tag", "--points-at", "HEAD", "--sort", "-version:refname"))
-		},
-		func() (string, error) {
-			return git.Clean(git.Run(ctx, "describe", "--tags", "--abbrev=0"))
+		func() ([]string, error) {
+			// this will get the last tag, even if it wasn't made against the
+			// last commit...
+			return git.CleanAllLines(gitDescribe(ctx, "HEAD"))
 		},
 	} {
-		tag, err = fn()
-		if tag != "" || err != nil {
-			return tag, err
+		tags, err := fn()
+		if len(tags) > 0 {
+			return tags[0], err
+		}
+		if err != nil {
+			return "", err
 		}
 	}
 
-	return tag, err
+	return "", nil
 }
 
 func getPreviousTag(ctx *context.Context, current string) (string, error) {
-	if tag := os.Getenv("GORELEASER_PREVIOUS_TAG"); tag != "" {
-		return tag, nil
+	for _, fn := range []func() ([]string, error){
+		getFromEnv("GORELEASER_PREVIOUS_TAG"),
+		func() ([]string, error) {
+			sha, err := previousTagSha(ctx, current)
+			if err != nil {
+				return nil, err
+			}
+			return gitTagsPointingAt(ctx, sha)
+		},
+	} {
+		tags, err := fn()
+		if len(tags) > 0 {
+			return tags[0], err
+		}
+		if err != nil {
+			return "", err
+		}
 	}
 
-	return git.Clean(git.Run(ctx, "describe", "--tags", "--abbrev=0", fmt.Sprintf("tags/%s^", current)))
+	return "", nil
+}
+
+func gitTagsPointingAt(ctx *context.Context, ref string) ([]string, error) {
+	return git.CleanAllLines(git.Run(
+		ctx,
+		"tag",
+		"--points-at",
+		ref,
+		"--sort",
+		"-version:refname",
+	))
+}
+
+func gitDescribe(ctx *context.Context, ref string) (string, error) {
+	return git.Clean(git.Run(
+		ctx,
+		"describe",
+		"--tags",
+		"--abbrev=0",
+		ref,
+	))
+}
+
+func previousTagSha(ctx *context.Context, current string) (string, error) {
+	tag, err := gitDescribe(ctx, fmt.Sprintf("tags/%s^", current))
+	if err != nil {
+		return "", err
+	}
+	return git.Clean(git.Run(ctx, "show", "--format='%h'", tag, "--quiet"))
 }
 
 func getURL(ctx *context.Context) (string, error) {
 	return git.Clean(git.Run(ctx, "ls-remote", "--get-url"))
 }
+
+func getFromEnv(s string) func() ([]string, error) {
+	return func() ([]string, error) {
+		if tag := os.Getenv(s); tag != "" {
+			return []string{tag}, nil
+		}
+		return nil, nil
+	}
+}