fix(api): allow missing required variable when a brick is added + app validation

internal/api/handlers/bricks.go

@@ -146,7 +146,7 @@ func HandleBrickCreate(
 		err = brickService.BrickCreate(req, app)
 		if err != nil {
 			// TODO: handle specific errors
-			slog.Error("Unable to parse the app.yaml", slog.String("error", err.Error()))
+			slog.Error("Unable to create brick", slog.String("error", err.Error()))
 			render.EncodeResponse(w, http.StatusInternalServerError, models.ErrorResponse{Details: "error while creating or updating brick"})
 			return
 		}

internal/orchestrator/app/parser.go

@@ -24,6 +24,8 @@ import (
 	"github.com/arduino/go-paths-helper"
 	"github.com/goccy/go-yaml"
 	"github.com/goccy/go-yaml/ast"
+
+	"github.com/arduino/arduino-app-cli/internal/orchestrator/bricksindex"
 )
 
 type Brick struct {
@@ -138,6 +140,44 @@ func (a *AppDescriptor) IsValid() error {
 	return allErrors
 }
 
+// ValidateBricks checks that all bricks referenced in the given AppDescriptor exist in the provided BricksIndex,
+// and that all required variables for each brick are present and valid. It collects and returns all validation
+// errors found as a slice, allowing the caller to see all issues at once rather than stopping at the first error.
+// If the index is nil, validation is skipped and nil is returned.
+func (a *AppDescriptor) ValidateBricks(index *bricksindex.BricksIndex) []error {
+	if index == nil {
+		return nil
+	}
+
+	var allErrors []error
+
+	for _, appBrick := range a.Bricks {
+		indexBrick, found := index.FindBrickByID(appBrick.ID)
+		if !found {
+			allErrors = append(allErrors, fmt.Errorf("brick %q not found", appBrick.ID))
+			continue // Skip further validation for this brick since it doesn't exist
+		}
+
+		// Check that all app variables exist in brick definition
+		for appBrickName := range appBrick.Variables {
+			_, exist := indexBrick.GetVariable(appBrickName)
+			if !exist {
+				allErrors = append(allErrors, fmt.Errorf("variable %q does not exist on brick %q", appBrickName, indexBrick.ID))
+			}
+		}
+
+		// Check that all required brick variables are provided by app
+		for _, indexBrickVariable := range indexBrick.Variables {
+			if indexBrickVariable.IsRequired() {
+				if _, exist := appBrick.Variables[indexBrickVariable.Name]; !exist {
+					allErrors = append(allErrors, fmt.Errorf("variable %q is required by brick %q", indexBrickVariable.Name, indexBrick.ID))
+				}
+			}
+		}
+	}
+	return allErrors
+}
+
 func isSingleEmoji(s string) bool {
 	emojis := 0
 	for it := emoji.IterateChars(s); it.Next(); {

internal/orchestrator/app/testdata/validator/all-required-app.yaml

@@ -0,0 +1,7 @@
+name: App ok
+description: App ok
+bricks:
+  - arduino:arduino_cloud:
+      variables:
+        ARDUINO_DEVICE_ID: "my-device-id"
+        ARDUINO_SECRET: "my-secret"

internal/orchestrator/app/testdata/validator/bricks-list.yaml

@@ -0,0 +1,9 @@
+bricks:
+- id: arduino:arduino_cloud
+  name: Arduino Cloud
+  description: Connects to Arduino Cloud
+  variables:
+  - name: ARDUINO_DEVICE_ID
+    description: Arduino Cloud Device ID
+  - name: ARDUINO_SECRET
+    description: Arduino Cloud Secret

internal/orchestrator/app/testdata/validator/empty-bricks-app.yaml

@@ -0,0 +1,4 @@
+name: App with empty bricks
+description: App with empty bricks
+
+bricks: []

internal/orchestrator/app/testdata/validator/empty-required-app.yaml

@@ -0,0 +1,7 @@
+name: App with an empty variable
+description: App withan empty variable
+bricks:
+  - arduino:arduino_cloud:
+      variables:
+        ARDUINO_DEVICE_ID: "my-device-id"
+        ARDUINO_SECRET:

internal/orchestrator/app/testdata/validator/no-bricks-app.yaml

@@ -0,0 +1,2 @@
+name: App with no bricks
+description: App with no bricks description

internal/orchestrator/app/testdata/validator/not-found-brick-app.yaml

@@ -0,0 +1,7 @@
+name: App no existing brick
+description: App no existing brick
+bricks:
+  - arduino:not_existing_brick:
+      variables:
+        ARDUINO_DEVICE_ID: "my-device-id"
+        ARDUINO_SECRET: "LAKDJ"

internal/orchestrator/app/testdata/validator/not-found-variable-app.yaml

@@ -0,0 +1,8 @@
+name: App with non existing variable
+description: App with non existing variable
+bricks:
+  - arduino:arduino_cloud:
+      variables:
+        NOT_EXISTING_VARIABLE: "this-is-a-not-existing-variable-for-the-brick"
+        ARDUINO_DEVICE_ID: "my-device-id"
+        ARDUINO_SECRET: "my-secret"

internal/orchestrator/app/testdata/validator/omitted-mixed-required-app.yaml

@@ -0,0 +1,6 @@
+name: App only one required variable filled
+description: App only one required variable filled
+bricks:
+  - arduino:arduino_cloud:
+      variables:
+        ARDUINO_DEVICE_ID: "my-device-id"

internal/orchestrator/app/testdata/validator/omitted-required-app.yaml

@@ -0,0 +1,4 @@
+name: App with no required variables
+description: App with no required variables
+bricks:
+  - arduino:arduino_cloud

internal/orchestrator/app/validator_test.go

@@ -0,0 +1,91 @@
+package app
+
+import (
+	"errors"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/arduino/go-paths-helper"
+
+	"github.com/arduino/arduino-app-cli/internal/orchestrator/bricksindex"
+)
+
+func TestValidateAppDescriptorBricks(t *testing.T) {
+	bricksIndex, err := bricksindex.GenerateBricksIndexFromFile(paths.New("testdata/validator"))
+	require.Nil(t, err)
+	require.NotNil(t, bricksIndex)
+
+	testCases := []struct {
+		name           string
+		filename       string
+		expectedErrors []error // Now expecting a slice of error messages
+	}{
+		{
+			name:           "valid with all required filled",
+			filename:       "all-required-app.yaml",
+			expectedErrors: nil,
+		},
+		{
+			name:           "valid with missing bricks",
+			filename:       "no-bricks-app.yaml",
+			expectedErrors: nil,
+		},
+		{
+			name:           "valid with empty list of bricks",
+			filename:       "empty-bricks-app.yaml",
+			expectedErrors: nil,
+		},
+		{
+			name:           "valid if required variable is empty string",
+			filename:       "empty-required-app.yaml",
+			expectedErrors: nil,
+		},
+		{
+			name:     "invalid if required variable is omitted",
+			filename: "omitted-required-app.yaml",
+			expectedErrors: []error{
+				errors.New("variable \"ARDUINO_DEVICE_ID\" is required by brick \"arduino:arduino_cloud\""),
+				errors.New("variable \"ARDUINO_SECRET\" is required by brick \"arduino:arduino_cloud\""),
+			},
+		},
+		{
+			name:     "invalid if a required variable among two is omitted",
+			filename: "omitted-mixed-required-app.yaml",
+			expectedErrors: []error{
+				errors.New("variable \"ARDUINO_SECRET\" is required by brick \"arduino:arduino_cloud\""),
+			},
+		},
+		{
+			name:     "invalid if brick id not found",
+			filename: "not-found-brick-app.yaml",
+			expectedErrors: []error{
+				errors.New("brick \"arduino:not_existing_brick\" not found"),
+			},
+		},
+		{
+			name:     "invalid if variable does not exist in the brick",
+			filename: "not-found-variable-app.yaml",
+			expectedErrors: []error{
+				errors.New("variable \"NOT_EXISTING_VARIABLE\" does not exist on brick \"arduino:arduino_cloud\""),
+			},
+		},
+	}
+
+	for _, tc := range testCases {
+		t.Run(tc.name, func(t *testing.T) {
+			appDescriptor, err := ParseDescriptorFile(paths.New("testdata/validator/" + tc.filename))
+			require.NoError(t, err)
+
+			errs := appDescriptor.ValidateBricks(bricksIndex)
+			if tc.expectedErrors == nil {
+				require.Nil(t, errs)
+				assert.Empty(t, errs, "Expected no validation errors")
+			} else {
+				require.Len(t, errs, len(tc.expectedErrors), "Expected %d errors but got %d", len(tc.expectedErrors), len(errs))
+				require.Exactly(t, tc.expectedErrors, errs)
+			}
+		})
+	}
+}

internal/orchestrator/bricks/bricks.go

@@ -290,7 +290,7 @@ func (s *Service) BrickCreate(
 	for _, brickVar := range brick.Variables {
 		if brickVar.DefaultValue == "" {
 			if _, exist := req.Variables[brickVar.Name]; !exist {
-				return fmt.Errorf("required variable %q is mandatory", brickVar.Name)
+				slog.Warn("[Skip] a required variable is not set by user", "variable", brickVar.Name)
 			}
 		}
 	}

internal/orchestrator/bricks/bricks_test.go

@@ -16,7 +16,9 @@
 package bricks
 
 import (
+	"fmt"
 	"testing"
+	"time"
 
 	"github.com/arduino/go-paths-helper"
 	"github.com/stretchr/testify/require"
@@ -32,7 +34,7 @@ func TestBrickCreate(t *testing.T) {
 	brickService := NewService(nil, bricksIndex, nil)
 
 	t.Run("fails if brick id does not exist", func(t *testing.T) {
-		err = brickService.BrickCreate(BrickCreateUpdateRequest{ID: "not-existing-id"}, f.Must(app.Load("testdata/dummy-app")))
+		err = brickService.BrickCreate(BrickCreateUpdateRequest{ID: "not-existing-id"}, f.Must(app.Load("testdata/AppFromExample")))
 		require.Error(t, err)
 		require.Equal(t, "brick \"not-existing-id\" not found", err.Error())
 	})
@@ -41,50 +43,59 @@ func TestBrickCreate(t *testing.T) {
 		req := BrickCreateUpdateRequest{ID: "arduino:arduino_cloud", Variables: map[string]string{
 			"NON_EXISTING_VARIABLE": "some-value",
 		}}
-		err = brickService.BrickCreate(req, f.Must(app.Load("testdata/dummy-app")))
+		err = brickService.BrickCreate(req, f.Must(app.Load("testdata/AppFromExample")))
 		require.Error(t, err)
 		require.Equal(t, "variable \"NON_EXISTING_VARIABLE\" does not exist on brick \"arduino:arduino_cloud\"", err.Error())
 	})
 
+	//TODO: currently we do not accept an empty string as a valid value for a variable
 	t.Run("fails if a required variable is set empty", func(t *testing.T) {
 		req := BrickCreateUpdateRequest{ID: "arduino:arduino_cloud", Variables: map[string]string{
 			"ARDUINO_DEVICE_ID": "",
 			"ARDUINO_SECRET":    "a-secret-a",
 		}}
-		err = brickService.BrickCreate(req, f.Must(app.Load("testdata/dummy-app")))
+		err = brickService.BrickCreate(req, f.Must(app.Load("testdata/AppFromExample")))
 		require.Error(t, err)
 		require.Equal(t, "variable \"ARDUINO_DEVICE_ID\" cannot be empty", err.Error())
 	})
 
-	t.Run("fails if a mandatory variable is not present in the request", func(t *testing.T) {
+	t.Run("omit a mandatory variable is not present in the request", func(t *testing.T) {
+		tempApp, cleanUp := copyToTempApp(t, paths.New("testdata/AppFromExample"))
+		defer cleanUp()
+
 		req := BrickCreateUpdateRequest{ID: "arduino:arduino_cloud", Variables: map[string]string{
 			"ARDUINO_SECRET": "a-secret-a",
 		}}
-		err = brickService.BrickCreate(req, f.Must(app.Load("testdata/dummy-app")))
-		require.Error(t, err)
-		require.Equal(t, "required variable \"ARDUINO_DEVICE_ID\" is mandatory", err.Error())
+		err = brickService.BrickCreate(req, f.Must(app.Load(tempApp.String())))
+		require.Nil(t, err)
+
+		after, err := app.Load(tempApp.String())
+		require.Nil(t, err)
+		require.Len(t, after.Descriptor.Bricks, 1)
+		require.Equal(t, "arduino:arduino_cloud", after.Descriptor.Bricks[0].ID)
+		// NOTE: currently it is not possible to distinguish a field with empty string or missing field into the yaml.
+		// The 'ARDUINO_DEVICE_ID' is missing from the app.yaml but here we check the empty string.
+		// A better aproach is to use golden files
+		require.Equal(t, "", after.Descriptor.Bricks[0].Variables["ARDUINO_DEVICE_ID"])
+		require.Equal(t, "a-secret-a", after.Descriptor.Bricks[0].Variables["ARDUINO_SECRET"])
 	})
 
 	t.Run("the brick is added if it does not exist in the app", func(t *testing.T) {
-		tempDummyApp := paths.New("testdata/dummy-app.temp")
-		err := tempDummyApp.RemoveAll()
-		require.Nil(t, err)
-		require.Nil(t, paths.New("testdata/dummy-app").CopyDirTo(tempDummyApp))
+		tempApp, cleanUp := copyToTempApp(t, paths.New("testdata/AppFromExample"))
+		defer cleanUp()
 
 		req := BrickCreateUpdateRequest{ID: "arduino:dbstorage_sqlstore"}
-		err = brickService.BrickCreate(req, f.Must(app.Load(tempDummyApp.String())))
+		err = brickService.BrickCreate(req, f.Must(app.Load(tempApp.String())))
 		require.Nil(t, err)
-		after, err := app.Load(tempDummyApp.String())
+		after, err := app.Load(tempApp.String())
 		require.Nil(t, err)
 		require.Len(t, after.Descriptor.Bricks, 2)
 		require.Equal(t, "arduino:dbstorage_sqlstore", after.Descriptor.Bricks[1].ID)
 	})
 	t.Run("the variables of a brick are updated", func(t *testing.T) {
-		tempDummyApp := paths.New("testdata/dummy-app.brick-override.temp")
-		err := tempDummyApp.RemoveAll()
-		require.Nil(t, err)
-		err = paths.New("testdata/dummy-app").CopyDirTo(tempDummyApp)
-		require.Nil(t, err)
+		tempApp, cleanUp := copyToTempApp(t, paths.New("testdata/AppFromExample"))
+		defer cleanUp()
+
 		bricksIndex, err := bricksindex.GenerateBricksIndexFromFile(paths.New("testdata"))
 		require.Nil(t, err)
 		brickService := NewService(nil, bricksIndex, nil)
@@ -99,10 +110,10 @@ func TestBrickCreate(t *testing.T) {
 			},
 		}
 
-		err = brickService.BrickCreate(req, f.Must(app.Load(tempDummyApp.String())))
+		err = brickService.BrickCreate(req, f.Must(app.Load(tempApp.String())))
 		require.Nil(t, err)
 
-		after, err := app.Load(tempDummyApp.String())
+		after, err := app.Load(tempApp.String())
 		require.Nil(t, err)
 		require.Len(t, after.Descriptor.Bricks, 1)
 		require.Equal(t, "arduino:arduino_cloud", after.Descriptor.Bricks[0].ID)
@@ -111,6 +122,14 @@ func TestBrickCreate(t *testing.T) {
 	})
 }
 
+func copyToTempApp(t *testing.T, srcApp *paths.Path) (tmpApp *paths.Path, cleanUp func()) {
+	tmpAppPath := paths.New(srcApp.String() + "-" + fmt.Sprint(time.Now().UnixMicro()) + ".temp")
+	require.Nil(t, srcApp.CopyDirTo(tmpAppPath))
+	return tmpAppPath, func() {
+		require.Nil(t, tmpAppPath.RemoveAll())
+	}
+}
+
 func TestGetBrickInstanceVariableDetails(t *testing.T) {
 	tests := []struct {
 		name                    string

internal/orchestrator/orchestrator.go

@@ -122,6 +122,16 @@ func StartApp(
 		ctx, cancel := context.WithCancel(ctx)
 		defer cancel()
 
+		errs := app.Descriptor.ValidateBricks(bricksIndex)
+		if errs != nil {
+			for _, e := range errs {
+				if !yield(StreamMessage{error: e}) {
+					return
+				}
+			}
+			return
+		}
+
 		running, err := getRunningApp(ctx, docker.Client())
 		if err != nil {
 			yield(StreamMessage{error: err})
@@ -446,6 +456,17 @@ func RestartApp(
 	return func(yield func(StreamMessage) bool) {
 		ctx, cancel := context.WithCancel(ctx)
 		defer cancel()
+
+		errs := appToStart.Descriptor.ValidateBricks(bricksIndex)
+		if errs != nil {
+			for _, e := range errs {
+				if !yield(StreamMessage{error: e}) {
+					return
+				}
+			}
+			return
+		}
+
 		runningApp, err := getRunningApp(ctx, docker.Client())
 		if err != nil {
 			yield(StreamMessage{error: err})