Modifying darwin brave version output (#31208)

drop lagging .0
add 58 to second version number and prepend

fixes #31122

# Checklist for submitter

- [x] Changes file added for user-visible changes in `changes/`,
`orbit/changes/` or `ee/fleetd-chrome/changes`.
See [Changes
files](https://github.com/fleetdm/fleet/blob/main/docs/Contributing/guides/committing-changes.md#changes-files)
for more information.
- [x] Added/updated automated tests
- [x] Manual QA for all new/changed functionality

ee/maintained-apps/ingesters/homebrew/external_refs/brave_version_transformer.go

@@ -0,0 +1,38 @@
+package externalrefs
+
+import (
+	"fmt"
+	"strconv"
+	"strings"
+
+	maintained_apps "github.com/fleetdm/fleet/v4/ee/maintained-apps"
+)
+
+func BraveVersionTransformer(app *maintained_apps.FMAManifestApp) (*maintained_apps.FMAManifestApp, error) {
+	var modifiedVersion string
+	homebrewVersion := app.Version
+	// Input format: 1.79.123.0
+
+	// drop lagging .0
+	if strings.HasSuffix(homebrewVersion, ".0") {
+		modifiedVersion = homebrewVersion[:len(homebrewVersion)-2]
+	} else {
+		return app, fmt.Errorf("Expected Brave version to end with '.0' but found '%s'", homebrewVersion)
+	}
+
+	// add 58 to second value
+	parts := strings.Split(modifiedVersion, ".")
+	if len(parts) == 3 {
+		if second, err := strconv.Atoi(parts[1]); err == nil {
+			parts = append([]string{fmt.Sprintf("%d", second+58)}, parts...)
+		} else {
+			return app, fmt.Errorf("Failed to parse '%s' of Brave version '%s': %v", parts[1], homebrewVersion, err)
+		}
+		// Output format: 137.1.79.123
+		app.Version = strings.Join(parts, ".")
+	} else {
+		return app, fmt.Errorf("Expected Brave version to have four parts but found '%s'", homebrewVersion)
+	}
+
+	return app, nil
+}

ee/maintained-apps/ingesters/homebrew/external_refs/brave_version_transformer_test.go

@@ -0,0 +1,64 @@
+package externalrefs
+
+import (
+	"testing"
+
+	maintained_apps "github.com/fleetdm/fleet/v4/ee/maintained-apps"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestBraveVersionTransformer(t *testing.T) {
+	t.Run("Version does not end with .0", func(t *testing.T) {
+		app := &maintained_apps.FMAManifestApp{
+			UniqueIdentifier: "brave-browser/darwin",
+			Version:          "1.79.123",
+		}
+		result, err := BraveVersionTransformer(app)
+		assert.Error(t, err)
+		assert.Equal(t, "Expected Brave version to end with '.0' but found '1.79.123'", err.Error())
+		assert.Equal(t, "1.79.123", result.Version)
+	})
+
+	t.Run("version has less than three parts after dropping .0", func(t *testing.T) {
+		app := &maintained_apps.FMAManifestApp{
+			UniqueIdentifier: "brave-browser/darwin",
+			Version:          "1.79.0",
+		}
+		result, err := BraveVersionTransformer(app)
+		assert.Error(t, err)
+		assert.Equal(t, "Expected Brave version to have four parts but found '1.79.0'", err.Error())
+		assert.Equal(t, "1.79.0", result.Version)
+	})
+
+	t.Run("version has more than three parts after dropping .0", func(t *testing.T) {
+		app := &maintained_apps.FMAManifestApp{
+			UniqueIdentifier: "brave-browser/darwin",
+			Version:          "1.1.1.79.0",
+		}
+		result, err := BraveVersionTransformer(app)
+		assert.Error(t, err)
+		assert.Equal(t, "Expected Brave version to have four parts but found '1.1.1.79.0'", err.Error())
+		assert.Equal(t, "1.1.1.79.0", result.Version)
+	})
+
+	t.Run("cannot parse second part as integer", func(t *testing.T) {
+		app := &maintained_apps.FMAManifestApp{
+			UniqueIdentifier: "brave-browser/darwin",
+			Version:          "1.a79.123.0",
+		}
+		result, err := BraveVersionTransformer(app)
+		assert.Error(t, err)
+		assert.Equal(t, "Failed to parse 'a79' of Brave version '1.a79.123.0': strconv.Atoi: parsing \"a79\": invalid syntax", err.Error())
+		assert.Equal(t, "1.a79.123.0", result.Version)
+	})
+
+	t.Run("Valid Brave Version", func(t *testing.T) {
+		app := &maintained_apps.FMAManifestApp{
+			UniqueIdentifier: "brave-browser/darwin",
+			Version:          "1.79.123.0",
+		}
+		result, err := BraveVersionTransformer(app)
+		assert.NoError(t, err)
+		assert.Equal(t, "137.1.79.123", result.Version)
+	})
+}

ee/maintained-apps/ingesters/homebrew/external_refs/main.go

@@ -9,6 +9,7 @@ import (
 var Funcs = map[string][]func(*maintained_apps.FMAManifestApp) (*maintained_apps.FMAManifestApp, error){
 	"microsoft-word/darwin":  {MicrosoftVersionFromReleaseNotes},
 	"microsoft-excel/darwin": {MicrosoftVersionFromReleaseNotes},
+	"brave-browser/darwin":   {BraveVersionTransformer},
 	"whatsapp/darwin":        {WhatsAppVersionShortener},
 	"google-chrome/darwin":   {ChromePKGInstaller},
 }

ee/maintained-apps/outputs/brave-browser/darwin.json

@@ -1,7 +1,7 @@
 {
   "versions": [
     {
-      "version": "1.79.126.0",
+      "version": "137.1.79.126",
       "queries": {
         "exists": "SELECT 1 FROM apps WHERE bundle_identifier = 'com.brave.Browser';"
       },