MM-16819 Helper function to build path to plugin asset (#13626)

Implement helper method to create a URL to the resource from a directory

plugin/helpers.go

@@ -83,6 +83,12 @@ type Helpers interface {
 	//
 	// Minimum server version: 5.18
 	InstallPluginFromURL(downloadURL string, replace bool) (*model.Manifest, error)
+
+	// GetPluginAssetURL builds a URL to the given asset in the assets directory.
+	// Use this URL to link to assets from the webapp, or for third-party integrations with your plugin.
+	//
+	// Minimum server version: 5.2
+	GetPluginAssetURL(pluginID, asset string) (string, error)
 }
 
 // HelpersImpl implements the helpers interface with an API that retrieves data on behalf of the plugin.

plugin/helpers_plugin.go

@@ -6,6 +6,7 @@ package plugin
 import (
 	"net/http"
 	"net/url"
+	"path"
 	"time"
 
 	"github.com/blang/semver"
@@ -54,3 +55,26 @@ func (p *HelpersImpl) ensureServerVersion(required string) error {
 	}
 	return nil
 }
+
+// GetPluginAssetURL implements GetPluginAssetURL.
+func (p *HelpersImpl) GetPluginAssetURL(pluginID, asset string) (string, error) {
+	if len(pluginID) == 0 {
+		return "", errors.New("empty pluginID provided")
+	}
+
+	if len(asset) == 0 {
+		return "", errors.New("empty asset name provided")
+	}
+
+	siteURL := *p.API.GetConfig().ServiceSettings.SiteURL
+	if siteURL == "" {
+		return "", errors.New("no SiteURL configured by the server")
+	}
+
+	u, err := url.Parse(siteURL + path.Join("/", pluginID, asset))
+	if err != nil {
+		return "", err
+	}
+
+	return u.String(), nil
+}

plugin/helpers_plugin_test.go

@@ -103,3 +103,74 @@ func TestInstallPluginFromURL(t *testing.T) {
 		assert.Equal(t, "received 404 status code while downloading plugin from server", err.Error())
 	})
 }
+
+func TestGetPluginAssetURL(t *testing.T) {
+	siteURL := "https://mattermost.example.com"
+	api := &plugintest.API{}
+	api.On("GetConfig").Return(&model.Config{ServiceSettings: model.ServiceSettings{SiteURL: &siteURL}})
+
+	p := &plugin.HelpersImpl{API: api}
+
+	t.Run("Valid asset directory was provided", func(t *testing.T) {
+		pluginID := "mattermost-1234"
+		dir := "assets"
+		wantedURL := "https://mattermost.example.com/mattermost-1234/assets"
+		gotURL, err := p.GetPluginAssetURL(pluginID, dir)
+
+		assert.Equalf(t, wantedURL, gotURL, "GetPluginAssetURL(%q, %q) got=%q; want=%v", pluginID, dir, gotURL, wantedURL)
+		assert.NoError(t, err)
+	})
+
+	t.Run("Valid asset directory path was provided", func(t *testing.T) {
+		pluginID := "mattermost-1234"
+		dirPath := "/mattermost/assets"
+		wantedURL := "https://mattermost.example.com/mattermost-1234/mattermost/assets"
+		gotURL, err := p.GetPluginAssetURL(pluginID, dirPath)
+
+		assert.Equalf(t, wantedURL, gotURL, "GetPluginAssetURL(%q, %q) got=%q; want=%q", pluginID, dirPath, gotURL, wantedURL)
+		assert.NoError(t, err)
+	})
+
+	t.Run("Valid pluginID was provided", func(t *testing.T) {
+		pluginID := "mattermost-1234"
+		dir := "assets"
+		wantedURL := "https://mattermost.example.com/mattermost-1234/assets"
+		gotURL, err := p.GetPluginAssetURL(pluginID, dir)
+
+		assert.Equalf(t, wantedURL, gotURL, "GetPluginAssetURL(%q, %q) got=%q; want=%q", pluginID, dir, gotURL, wantedURL)
+		assert.NoError(t, err)
+	})
+
+	t.Run("Invalid asset directory name was provided", func(t *testing.T) {
+		pluginID := "mattermost-1234"
+		dir := ""
+		want := ""
+		gotURL, err := p.GetPluginAssetURL(pluginID, dir)
+
+		assert.Emptyf(t, gotURL, "GetPluginAssetURL(%q, %q) got=%s; want=%q", pluginID, dir, gotURL, want)
+		assert.Error(t, err)
+	})
+
+	t.Run("Invalid pluginID was provided", func(t *testing.T) {
+		pluginID := ""
+		dir := "assets"
+		want := ""
+		gotURL, err := p.GetPluginAssetURL(pluginID, dir)
+
+		assert.Emptyf(t, gotURL, "GetPluginAssetURL(%q, %q) got=%q; want=%q", pluginID, dir, gotURL, want)
+		assert.Error(t, err)
+	})
+
+	siteURL = ""
+	api.On("GetConfig").Return(&model.Config{ServiceSettings: model.ServiceSettings{SiteURL: &siteURL}})
+
+	t.Run("Empty SiteURL was configured", func(t *testing.T) {
+		pluginID := "mattermost-1234"
+		dir := "assets"
+		want := ""
+		gotURL, err := p.GetPluginAssetURL(pluginID, dir)
+
+		assert.Emptyf(t, gotURL, "GetPluginAssetURL(%q, %q) got=%q; want=%q", pluginID, dir, gotURL, want)
+		assert.Error(t, err)
+	})
+}

plugin/plugintest/helpers.go

@@ -64,6 +64,27 @@ func (_m *Helpers) EnsureBot(bot *model.Bot, options ...plugin.EnsureBotOption)
 	return r0, r1
 }
 
+// GetPluginAssetURL provides a mock function with given fields: pluginID, asset
+func (_m *Helpers) GetPluginAssetURL(pluginID string, asset string) (string, error) {
+	ret := _m.Called(pluginID, asset)
+
+	var r0 string
+	if rf, ok := ret.Get(0).(func(string, string) string); ok {
+		r0 = rf(pluginID, asset)
+	} else {
+		r0 = ret.Get(0).(string)
+	}
+
+	var r1 error
+	if rf, ok := ret.Get(1).(func(string, string) error); ok {
+		r1 = rf(pluginID, asset)
+	} else {
+		r1 = ret.Error(1)
+	}
+
+	return r0, r1
+}
+
 // InstallPluginFromURL provides a mock function with given fields: downloadURL, replace
 func (_m *Helpers) InstallPluginFromURL(downloadURL string, replace bool) (*model.Manifest, error) {
 	ret := _m.Called(downloadURL, replace)