fix `arduino-cli outdated --format json` output (#1746)

cli/outdated/outdated.go

@@ -57,25 +57,42 @@ func runOutdatedCommand(cmd *cobra.Command, args []string) {
 		feedback.Errorf(tr("Error retrieving outdated cores and libraries: %v"), err)
 	}
 
+	feedback.PrintResult(outdatedResult{
+		Platforms: outdatedResp.OutdatedPlatforms,
+		Libraries: outdatedResp.OutdatedLibraries})
+}
+
+// output from this command requires special formatting, let's create a dedicated
+// feedback.Result implementation
+type outdatedResult struct {
+	Platforms []*rpc.Platform
+	Libraries []*rpc.InstalledLibrary
+}
+
+func (or outdatedResult) Data() interface{} {
+	return or
+}
+
+func (or outdatedResult) String() string {
 	// Prints outdated cores
-	tab := table.New()
-	tab.SetHeader(tr("ID"), tr("Installed version"), tr("New version"), tr("Name"))
-	if len(outdatedResp.OutdatedPlatforms) > 0 {
-		for _, p := range outdatedResp.OutdatedPlatforms {
-			tab.AddRow(p.Id, p.Installed, p.Latest, p.Name)
+	t1 := table.New()
+	if len(or.Platforms) > 0 {
+		t1.SetHeader(tr("ID"), tr("Installed version"), tr("New version"), tr("Name"))
+		for _, p := range or.Platforms {
+			t1.AddRow(p.Id, p.Installed, p.Latest, p.Name)
 		}
-		feedback.Print(tab.Render())
 	}
 
 	// Prints outdated libraries
-	tab = table.New()
-	tab.SetHeader(tr("Library name"), tr("Installed version"), tr("New version"))
-	if len(outdatedResp.OutdatedLibraries) > 0 {
-		for _, l := range outdatedResp.OutdatedLibraries {
-			tab.AddRow(l.Library.Name, l.Library.Version, l.Release.Version)
+	t2 := table.New()
+	if len(or.Libraries) > 0 {
+		t2.SetHeader(tr("Library name"), tr("Installed version"), tr("New version"))
+		for _, l := range or.Libraries {
+			t2.AddRow(l.Library.Name, l.Library.Version, l.Release.Version)
 		}
-		feedback.Print(tab.Render())
 	}
-
-	logrus.Info("Done")
+	if len(or.Libraries) > 0 && len(or.Platforms) > 0 {
+		return t1.Render() + "\n" + t2.Render() // handle the new line between tables
+	}
+	return t1.Render() + t2.Render()
 }

test/test_upgrade.py

@@ -42,7 +42,7 @@ def test_upgrade(run_command):
     # Verifies cores and libraries have been updated
     result = run_command(["outdated"])
     assert result.ok
-    assert result.stdout == ""
+    assert result.stdout == "\n"
 
 
 def test_upgrade_using_library_with_invalid_version(run_command, data_dir):