From cfb9df99e57e6b0d464dd8b85d4c91ff2c28982f Mon Sep 17 00:00:00 2001
From: Ben Meier <ben.meier@humanitec.com>
Date: Fri, 23 Feb 2024 16:27:19 +0000
Subject: [PATCH] chore: added ApplyCommonUpgradeTransforms

Signed-off-by: Ben Meier <ben.meier@humanitec.com>
---
 schema/validate.go      | 59 +++++++++++++++++++++++++++++++++++++++++
 schema/validate_test.go | 41 ++++++++++++++++++++++++++++
 2 files changed, 100 insertions(+)

diff --git a/schema/validate.go b/schema/validate.go
index 3998265..4ac3987 100644
--- a/schema/validate.go
+++ b/schema/validate.go
@@ -11,6 +11,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"io"
+	"strings"
 
 	"github.com/santhosh-tekuri/jsonschema/v5"
 	"gopkg.in/yaml.v3"
@@ -56,3 +57,61 @@ func Validate(src interface{}) error {
 
 	return schema.Validate(src)
 }
+
+// ApplyCommonUpgradeTransforms when we fix aspects of the score spec over time, we sometimes need to break compatibility.
+// To reduce affects on users, we can apply a sequence of transformations to the yaml decoded structure so that we can
+// fix things on their behalf. This reduces the impact on existing workflows. This function returns messages regarding
+// any changes it has made or an error if the structure was unexpected.
+// NOTE: this method should only be used for tools or utilities where there is already an established use-case and
+// workflow for example score-compose and score-humanitec.
+func ApplyCommonUpgradeTransforms(rawScore map[string]interface{}) ([]string, error) {
+	changes := make([]string, 0)
+
+	if containersStruct, ok := rawScore["containers"].(map[string]interface{}); ok {
+		for name, rawContainerStruct := range containersStruct {
+			containerStruct, ok := rawContainerStruct.(map[string]interface{})
+			if !ok {
+				continue
+			}
+
+			// We no longer support multi-line content. Update any arrays in line to be newline-separated
+			if filesStruct, ok := containerStruct["files"].([]interface{}); ok {
+				for i, rawFileStruct := range filesStruct {
+					fileStruct, ok := rawFileStruct.(map[string]interface{})
+					if !ok {
+						continue
+					}
+					if before, ok := fileStruct["content"].([]interface{}); ok {
+						delete(fileStruct, "content")
+						sb := new(strings.Builder)
+						for il, line := range before {
+							if il > 0 {
+								sb.WriteRune('\n')
+							}
+							sb.WriteString(fmt.Sprint(line))
+						}
+						fileStruct["content"] = sb.String()
+						changes = append(changes, fmt.Sprintf("containers.%s.files.%d.content: converted from array", name, i))
+					}
+				}
+			}
+
+			// We have fixed the naming of the read_only field. It is now readOnly.
+			if volumesStruct, ok := containerStruct["volumes"].([]interface{}); ok {
+				for i, rawVolumeStruct := range volumesStruct {
+					volumeStruct, ok := rawVolumeStruct.(map[string]interface{})
+					if !ok {
+						continue
+					}
+					if before, ok := volumeStruct["read_only"].(bool); ok {
+						delete(volumeStruct, "read_only")
+						volumeStruct["readOnly"] = before
+						changes = append(changes, fmt.Sprintf("containers.%s.volumes.%d.read_only: migrated to readOnly", name, i))
+					}
+				}
+			}
+		}
+	}
+
+	return changes, nil
+}
diff --git a/schema/validate_test.go b/schema/validate_test.go
index 38aa071..259902f 100644
--- a/schema/validate_test.go
+++ b/schema/validate_test.go
@@ -12,6 +12,7 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"gopkg.in/yaml.v3"
 )
 
 func TestValidateYaml(t *testing.T) {
@@ -398,3 +399,43 @@ containers:
 	err := ValidateYaml(bytes.NewReader(source))
 	assert.EqualError(t, err, "jsonschema: '/metadata' does not validate with https://score.dev/schemas/score#/properties/metadata/required: missing properties: 'name'")
 }
+
+func TestApplyCommonUpgradeTransforms(t *testing.T) {
+	var source = []byte(`
+---
+apiVersion: score.dev/v1b1
+metadata:
+  name: hello-world
+containers:
+  hello:
+    image: busybox
+    files:
+    - target: /etc/hello-world/config.yaml
+      mode: "666"
+      content:
+      - line1
+      - line2
+    volumes:
+    - source: ${resources.data}
+      target: /mnt/data
+      read_only: true
+`)
+
+	var obj map[string]interface{}
+	var dec = yaml.NewDecoder(bytes.NewReader(source))
+	assert.NoError(t, dec.Decode(&obj))
+
+	// first validation attempt should fail
+	assert.Error(t, Validate(obj))
+
+	// apply transforms
+	changes, err := ApplyCommonUpgradeTransforms(obj)
+	assert.NoError(t, err)
+	assert.Len(t, changes, 2)
+
+	// second validation attempt should succeed
+	assert.NoError(t, Validate(obj))
+
+	assert.Equal(t, "line1\nline2", obj["containers"].(map[string]interface{})["hello"].(map[string]interface{})["files"].([]interface{})[0].(map[string]interface{})["content"])
+	assert.Equal(t, true, obj["containers"].(map[string]interface{})["hello"].(map[string]interface{})["volumes"].([]interface{})[0].(map[string]interface{})["readOnly"])
+}