Read settings for a config-form module that mesh-config holds, not only for one with a settings row (issue 1493)

cmd/mesh-controller/compose_input_settings_test.go

@@ -0,0 +1,45 @@
+package main
+
+import (
+	"errors"
+	"reflect"
+	"testing"
+
+	"git.novox.be/novox/mesh-sdk/go/catalogue"
+)
+
+// configForm is a module in the config form, shaped as a real one (inventory's config_move_test).
+func configForm(t *testing.T, name string) catalogue.Manifest {
+	t.Helper()
+	m, err := catalogue.ParseManifest([]byte(`{"module": "` + name + `", "version": "1",
+		"config": {"level": {"type": "string", "description": "how much it says", "default": "info"}},
+		"resources": [{"id": "conf", "type": "file", "path": "/etc/` + name + `.json", "mode": "0640",
+			"content": "{\"level\": \"info\"}", "merge": "json", "takes-config": ["level"]}]}`))
+	if err != nil {
+		t.Fatal(err)
+	}
+	return m
+}
+
+// Issue 1493: a module in the config form whose values are set only in mesh-config has no settings row, and its
+// settings are still read, because SettingsFor is where mesh-config's values are laid in.
+func TestSettingsAreReadForAConfigModuleWithoutASettingsRow(t *testing.T) {
+	shelf := map[string]catalogue.Manifest{
+		"brother": configForm(t, "brother"),        // config only in mesh-config: no settings row
+		"older":   {Module: "older", Version: "1"}, // settings form, with a row
+		"idle":    {Module: "idle", Version: "1"},  // settings form, no row: nothing to read
+		"newer":   configForm(t, "newer"),          // config form, but the switch is off for it
+	}
+	have := map[string]bool{"older": true, "gone": true} // "gone" has a row and is not on the shelf
+	reads := func(module string) (bool, error) { return module == "brother", nil }
+	got, err := modulesToRead(shelf, have, reads)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if want := []string{"brother", "older"}; !reflect.DeepEqual(got, want) {
+		t.Errorf("settings are read for %v, want %v", got, want)
+	}
+	if _, err := modulesToRead(shelf, have, func(string) (bool, error) { return false, errors.New("store down") }); err == nil {
+		t.Error("a failing ReadsConfig is not returned")
+	}
+}