fix: merge Prompts from referenced modelkits during Kitfile resolution

The mergeKitfiles function merges Code, DataSets, and Docs when
resolving modelkit references, but silently drops Prompts. This
means any prompts attached to referenced ModelKits are lost.

Add the missing Prompts merge to match the existing pattern used
for other slice fields (Code, DataSets, Docs).

Signed-off-by: Adesh Deshmukh <adeshkd123@gmail.com>

Author: AdeshDeshmukh

pkg/lib/kitfile/resolve.go

@@ -133,6 +133,8 @@ func mergeKitfiles(into, from *artifact.KitFile) *artifact.KitFile {
 	result.DataSets = append(result.DataSets, from.DataSets...)
 	result.Docs = into.Docs
 	result.Docs = append(result.Docs, from.Docs...)
+	result.Prompts = into.Prompts
+	result.Prompts = append(result.Prompts, from.Prompts...)
 	return result
 }
 

pkg/lib/kitfile/resolve_test.go

@@ -0,0 +1,123 @@
+// Copyright 2024 The KitOps Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+// SPDX-License-Identifier: Apache-2.0
+
+package kitfile
+
+import (
+	"testing"
+
+	"github.com/kitops-ml/kitops/pkg/artifact"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestMergeKitfiles_Prompts(t *testing.T) {
+	prompt1 := artifact.Prompt{Name: "prompt1", Path: "prompts/p1.txt", Description: "first prompt"}
+	prompt2 := artifact.Prompt{Name: "prompt2", Path: "prompts/p2.txt", Description: "second prompt"}
+	prompt3 := artifact.Prompt{Name: "prompt3", Path: "prompts/p3.txt", Description: "third prompt"}
+
+	tests := []struct {
+		name     string
+		into     *artifact.KitFile
+		from     *artifact.KitFile
+		expected []artifact.Prompt
+	}{
+		{
+			name:     "both nil prompts",
+			into:     &artifact.KitFile{},
+			from:     &artifact.KitFile{},
+			expected: nil,
+		},
+		{
+			name:     "into has prompts, from has none",
+			into:     &artifact.KitFile{Prompts: []artifact.Prompt{prompt1, prompt2}},
+			from:     &artifact.KitFile{},
+			expected: []artifact.Prompt{prompt1, prompt2},
+		},
+		{
+			name:     "from has prompts, into has none",
+			into:     &artifact.KitFile{},
+			from:     &artifact.KitFile{Prompts: []artifact.Prompt{prompt2, prompt3}},
+			expected: []artifact.Prompt{prompt2, prompt3},
+		},
+		{
+			name:     "both have prompts — merged in order",
+			into:     &artifact.KitFile{Prompts: []artifact.Prompt{prompt1}},
+			from:     &artifact.KitFile{Prompts: []artifact.Prompt{prompt2, prompt3}},
+			expected: []artifact.Prompt{prompt1, prompt2, prompt3},
+		},
+		{
+			name:     "overlapping prompts — all preserved",
+			into:     &artifact.KitFile{Prompts: []artifact.Prompt{prompt1, prompt2}},
+			from:     &artifact.KitFile{Prompts: []artifact.Prompt{prompt2, prompt3}},
+			expected: []artifact.Prompt{prompt1, prompt2, prompt2, prompt3},
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := mergeKitfiles(tt.into, tt.from)
+			assert.Equal(t, tt.expected, result.Prompts, "Prompts mismatch")
+		})
+	}
+}
+
+func TestMergeKitfiles_PreservesOtherFields(t *testing.T) {
+	into := &artifact.KitFile{
+		ManifestVersion: "1.0.0",
+		Package: artifact.Package{
+			Name: "into-pkg",
+		},
+		Code:     []artifact.Code{{Path: "into/code.py"}},
+		DataSets: []artifact.DataSet{{Path: "into/data.csv"}},
+		Docs:     []artifact.Docs{{Path: "into/doc.md"}},
+		Prompts:  []artifact.Prompt{{Name: "into-prompt", Path: "into/prompt.txt"}},
+	}
+	from := &artifact.KitFile{
+		ManifestVersion: "1.0.0",
+		Package: artifact.Package{
+			Name: "from-pkg",
+		},
+		Code:     []artifact.Code{{Path: "from/code.py"}},
+		DataSets: []artifact.DataSet{{Path: "from/data.csv"}},
+		Docs:     []artifact.Docs{{Path: "from/doc.md"}},
+		Prompts:  []artifact.Prompt{{Name: "from-prompt", Path: "from/prompt.txt"}},
+	}
+
+	result := mergeKitfiles(into, from)
+
+	assert.Len(t, result.Prompts, 2, "should have prompts from both")
+	assert.Equal(t, "into-prompt", result.Prompts[0].Name, "into prompts should come first")
+	assert.Equal(t, "from-prompt", result.Prompts[1].Name, "from prompts should come second")
+
+	assert.Len(t, result.Code, 2, "code should still merge")
+	assert.Len(t, result.DataSets, 2, "datasets should still merge")
+	assert.Len(t, result.Docs, 2, "docs should still merge")
+	assert.Equal(t, "into-pkg", result.Package.Name, "package name should use firstNonEmpty")
+}
+
+func TestMergeKitfiles_DoesNotMutateInput(t *testing.T) {
+	intoPrompts := []artifact.Prompt{{Name: "p1"}, {Name: "p2"}}
+	fromPrompts := []artifact.Prompt{{Name: "p3"}}
+
+	into := &artifact.KitFile{Prompts: intoPrompts}
+	from := &artifact.KitFile{Prompts: fromPrompts}
+
+	result := mergeKitfiles(into, from)
+
+	assert.Len(t, result.Prompts, 3, "result should have 3 prompts")
+	assert.Len(t, into.Prompts, 2, "input 'into' should be unmodified")
+	assert.Len(t, from.Prompts, 1, "input 'from' should be unmodified")
+}