Map postgres autoscaling fields to float64 in bundle TF schema (#4398)

## Changes

Added allowlist to Terraform schema generator to emit `float64` for
postgres autoscaling fields. All other number fields remain `int`.

Note: Other fields (cluster_cores, spot_bid_max_price, etc.) also need
float64 but are deferred to handle postgres resources first. These are
not implemented yet so changing them doesn't impact anything.

## Why

Postgres autoscaling supports fractional CU values (e.g., 0.5). The
previous implementation mapped all `cty.Number` to `int`, truncating
fractional values and mismatching databricks-sdk-go types.

## Tests

Verified postgres autoscaling fields are `float64` and other number
fields remain `int`.

---------

Co-authored-by: Claude Sonnet 4.5 <noreply@anthropic.com>

Author: pietern

bundle/internal/tf/codegen/generator/named_block.go

@@ -43,7 +43,7 @@ func (b *namedBlock) camelName() string {
 }
 
 func (b *namedBlock) Generate(path string) error {
-	w, err := walk(b.block, []string{b.typeNamePrefix, b.camelName()})
+	w, err := walk(b.block, []string{b.typeNamePrefix, b.camelName()}, b.name)
 	if err != nil {
 		return err
 	}

bundle/internal/tf/codegen/generator/walker.go

@@ -25,10 +25,59 @@ type structType struct {
 // represent a [tfjson.SchemaBlock] as Go structs.
 // See the [walk] function for usage.
 type walker struct {
-	StructTypes []structType
+	StructTypes  []structType
+	resourceName string // The Terraform resource name (e.g., "databricks_postgres_endpoint")
 }
 
-func processAttributeType(typ cty.Type) string {
+// floatAttributePaths is an allowlist of attribute paths (resource_name.field_path)
+// that should be mapped to float64 instead of int for cty.Number types.
+// Generated from Terraform provider schema based on databricks-sdk-go types.
+var floatAttributePaths = map[string]bool{
+	// Postgres Service - autoscaling compute units support fractional values (e.g., 0.5 CU)
+	"databricks_postgres_endpoint.spec.autoscaling_limit_max_cu":                                      true,
+	"databricks_postgres_endpoint.spec.autoscaling_limit_min_cu":                                      true,
+	"databricks_postgres_endpoint.status.autoscaling_limit_max_cu":                                    true,
+	"databricks_postgres_endpoint.status.autoscaling_limit_min_cu":                                    true,
+	"databricks_postgres_endpoints.endpoints.spec.autoscaling_limit_max_cu":                           true,
+	"databricks_postgres_endpoints.endpoints.spec.autoscaling_limit_min_cu":                           true,
+	"databricks_postgres_endpoints.endpoints.status.autoscaling_limit_max_cu":                         true,
+	"databricks_postgres_endpoints.endpoints.status.autoscaling_limit_min_cu":                         true,
+	"databricks_postgres_project.spec.default_endpoint_settings.autoscaling_limit_max_cu":             true,
+	"databricks_postgres_project.spec.default_endpoint_settings.autoscaling_limit_min_cu":             true,
+	"databricks_postgres_project.status.default_endpoint_settings.autoscaling_limit_max_cu":           true,
+	"databricks_postgres_project.status.default_endpoint_settings.autoscaling_limit_min_cu":           true,
+	"databricks_postgres_projects.projects.spec.default_endpoint_settings.autoscaling_limit_max_cu":   true,
+	"databricks_postgres_projects.projects.spec.default_endpoint_settings.autoscaling_limit_min_cu":   true,
+	"databricks_postgres_projects.projects.status.default_endpoint_settings.autoscaling_limit_max_cu": true,
+	"databricks_postgres_projects.projects.status.default_endpoint_settings.autoscaling_limit_min_cu": true,
+}
+
+// buildAttributePath constructs the attribute path from the type name path.
+// For example: ["Resource", "PostgresEndpoint", "Spec"] + "autoscaling_limit_min_cu" -> "spec.autoscaling_limit_min_cu"
+func buildAttributePath(name []string, fieldName string) string {
+	// Skip the type prefix (Resource/DataSource) and resource name (first 2 elements)
+	// and convert remaining CamelCase to snake_case
+	var parts []string
+	for i := 2; i < len(name); i++ {
+		parts = append(parts, toSnakeCase(name[i]))
+	}
+	parts = append(parts, fieldName)
+	return strings.Join(parts, ".")
+}
+
+// toSnakeCase converts CamelCase to snake_case
+func toSnakeCase(s string) string {
+	var result strings.Builder
+	for i, r := range s {
+		if i > 0 && 'A' <= r && r <= 'Z' {
+			result.WriteRune('_')
+		}
+		result.WriteRune(r)
+	}
+	return strings.ToLower(result.String())
+}
+
+func processAttributeType(typ cty.Type, resourceName, attributePath string) string {
 	var out string
 
 	switch {
@@ -37,18 +86,24 @@ func processAttributeType(typ cty.Type) string {
 		case typ.Equals(cty.Bool):
 			out = "bool"
 		case typ.Equals(cty.Number):
-			out = "int"
+			// Check if this resource + attribute path should be float64
+			fullPath := resourceName + "." + attributePath
+			if floatAttributePaths[fullPath] {
+				out = "float64"
+			} else {
+				out = "int"
+			}
 		case typ.Equals(cty.String):
 			out = "string"
 		default:
 			panic("No idea what to do for: " + typ.FriendlyName())
 		}
 	case typ.IsMapType():
-		out = "map[string]" + processAttributeType(*typ.MapElementType())
+		out = "map[string]" + processAttributeType(*typ.MapElementType(), resourceName, attributePath)
 	case typ.IsSetType():
-		out = "[]" + processAttributeType(*typ.SetElementType())
+		out = "[]" + processAttributeType(*typ.SetElementType(), resourceName, attributePath)
 	case typ.IsListType():
-		out = "[]" + processAttributeType(*typ.ListElementType())
+		out = "[]" + processAttributeType(*typ.ListElementType(), resourceName, attributePath)
 	case typ.IsObjectType():
 		out = "any"
 	default:
@@ -129,7 +184,8 @@ func (w *walker) walk(block *tfjson.SchemaBlock, name []string) error {
 
 		// Collect field properties.
 		fieldName := strcase.ToCamel(k)
-		fieldType := processAttributeType(v.AttributeType)
+		attributePath := buildAttributePath(name, k)
+		fieldType := processAttributeType(v.AttributeType, w.resourceName, attributePath)
 		fieldTag := k
 		if v.Required && v.Optional {
 			return fmt.Errorf("both required and optional are set for attribute %s", k)
@@ -160,8 +216,9 @@ func (w *walker) walk(block *tfjson.SchemaBlock, name []string) error {
 
 // walk recursively traverses [tfjson.SchemaBlock] and returns the
 // set of types to declare to represents it as Go structs.
-func walk(block *tfjson.SchemaBlock, name []string) (*walker, error) {
-	w := &walker{}
+// The resourceName parameter is the Terraform resource name (e.g., "databricks_postgres_endpoint").
+func walk(block *tfjson.SchemaBlock, name []string, resourceName string) (*walker, error) {
+	w := &walker{resourceName: resourceName}
 	err := w.walk(block, name)
 	return w, err
 }