Add end to end tests to validate the generated JSON schema

.github/workflows/push.yml

@@ -115,3 +115,9 @@ jobs:
         run: |
           go run main.go bundle schema > schema.json
           ajv -s schema.json -d ./bundle/tests/basic/databricks.yml
+
+          # Valid configuration should pass schema validation.
+          for file in ./bundle/tests/jsonschema/allowed/*.yml; do
+            echo "validating $file"
+            ajv -s schema.json -d $file
+          done

bundle/config/mutator/resolve_variable_references.go

@@ -137,7 +137,7 @@ func (m *resolveVariableReferences) Apply(ctx context.Context, b *bundle.Bundle)
 		normalized, _ := convert.Normalize(b.Config, root, convert.IncludeMissingFields)
 
 		// If the pattern is nil, we resolve references in the entire configuration.
-		root, err := dyn.MapByPattern(root, m.pattern, func(p dyn.Path, v dyn.Value) (dyn.Value, error) {
+		root, err := dyn.MapByPattern(root, m.pattern, func(_ dyn.Path, v dyn.Value) (dyn.Value, error) {
 			// Resolve variable references in all values.
 			return dynvar.Resolve(v, func(path dyn.Path) (dyn.Value, error) {
 				// Rewrite the shorthand path ${var.foo} into ${variables.foo.value}.

bundle/tests/jsonschema/allowed/var-reference.yml

@@ -0,0 +1,18 @@
+bundle:
+  name: variable reference string
+
+variables:
+  my_var:
+    description: does not matter
+    default: "hello"
+
+resources:
+  jobs:
+    foo:
+      name: ${var.my_var}
+
+targets:
+  staging:
+    default: true
+    variables:
+      my_var: "world"