coop: validate blueprint node references

pkg/coop/blueprint.go

@@ -4,13 +4,16 @@ import (
 	"embed"
 	"encoding/json"
 	"fmt"
+	"regexp"
 	"strings"
 	"time"
 )
 
 //go:embed blueprints/*.json
 var blueprintFS embed.FS
 
+var blueprintNodeRefRE = regexp.MustCompile(`\$\{node\.([^}:]+):[^}]+\}`)
+
 // BlueprintStep is a step definition within a blueprint.
 type BlueprintStep struct {
 	StepDefinition
@@ -74,10 +77,56 @@ func LoadBlueprint(id string) (*Blueprint, error) {
 	if err := json.Unmarshal(data, &bp); err != nil {
 		return nil, fmt.Errorf("parsing blueprint %q: %w", id, err)
 	}
+	if err := validateBlueprintReferences(&bp); err != nil {
+		return nil, fmt.Errorf("validating blueprint %q: %w", id, err)
+	}
 
 	return &bp, nil
 }
 
+func validateBlueprintReferences(bp *Blueprint) error {
+	validRefs := map[string]bool{}
+	for _, step := range bp.Steps {
+		for _, node := range step.Nodes {
+			validRefs[step.Key+"."+node.Key] = true
+			for _, request := range node.TestRequests {
+				if request.Key != "" {
+					validRefs[step.Key+"."+node.Key+"."+request.Key] = true
+				}
+			}
+		}
+	}
+
+	data, err := json.Marshal(bp)
+	if err != nil {
+		return err
+	}
+	for _, match := range blueprintNodeRefRE.FindAllSubmatch(data, -1) {
+		ref := string(match[1])
+		if validRefs[ref] {
+			continue
+		}
+		parts := strings.Split(ref, ".")
+		if len(parts) == 3 && validRefs[parts[0]+"."+parts[1]] && isIntegerRefSegment(parts[2]) {
+			continue
+		}
+		return fmt.Errorf("unknown node reference %q", ref)
+	}
+	return nil
+}
+
+func isIntegerRefSegment(value string) bool {
+	if value == "" {
+		return false
+	}
+	for _, r := range value {
+		if r < '0' || r > '9' {
+			return false
+		}
+	}
+	return true
+}
+
 func prefixMatchBlueprint(prefix string) (string, error) {
 	ids, err := ListBlueprints()
 	if err != nil {

pkg/coop/blueprint_test.go

@@ -103,6 +103,41 @@ func TestLoadBlueprintNotFound(t *testing.T) {
 	assert.Error(t, err)
 }
 
+func TestValidateBlueprintReferences(t *testing.T) {
+	bp := &Blueprint{
+		ID: "test",
+		Steps: []BlueprintStep{
+			{
+				StepDefinition: StepDefinition{Key: "setup", Title: "Setup"},
+				Nodes: []NodeDefinition{
+					{Key: "create-product", Request: &APIRequest{Path: "/v1/products", Method: "post"}},
+					{Key: "create-clock", TestRequests: []TestHelperRequest{{
+						Key: "create-clock-request",
+						APIRequest: APIRequest{
+							Path:   "/v1/test_helpers/test_clocks",
+							Method: "post",
+						},
+					}}},
+					{Key: "create-checkout", Request: &APIRequest{
+						Path:   "/v1/checkout/sessions",
+						Method: "post",
+						Params: map[string]string{
+							"price": "${node.setup.create-product:default_price}",
+						},
+					}},
+					{Key: "view-clock", Request: &APIRequest{Path: "/v1/test_helpers/test_clocks/${node.setup.create-clock.create-clock-request:id}", Method: "get"}},
+				},
+			},
+		},
+	}
+	require.NoError(t, validateBlueprintReferences(bp))
+
+	bp.Steps[0].Nodes[3].Request.Path = "/v1/products/${node.old.create-product:id}"
+	err := validateBlueprintReferences(bp)
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "unknown node reference")
+}
+
 func TestLoadBlueprintPrefixMatch(t *testing.T) {
 	bp, err := LoadBlueprint("setup-future")
 	require.NoError(t, err)