PoC: Add plan modifier to selected_fields

internal/planmodifiers/listplanmodifier/ensure_selected_fields_diff.go

@@ -0,0 +1,95 @@
+package listplanmodifier
+
+import (
+	"context"
+	"fmt"
+	"slices"
+
+	"github.com/airbytehq/terraform-provider-airbyte/internal/planmodifiers/utils"
+
+	"github.com/hashicorp/terraform-plugin-framework/resource/schema/planmodifier"
+	"github.com/hashicorp/terraform-plugin-framework/types"
+)
+
+// EnsureSelectedFieldsDiff returns a plan modifier for streams ensuring the order of field paths is consistent
+func EnsureSelectedFieldsDiff() planmodifier.List {
+	return ensureSelectedFieldsDiff{}
+}
+
+// ensureSelectedFieldsDiff implements the plan modifier.
+type ensureSelectedFieldsDiff struct{}
+
+// Description returns a human-readable description of the plan modifier.
+func (m ensureSelectedFieldsDiff) Description(_ context.Context) string {
+	return "Ensure the order of field paths is consistent"
+}
+
+// MarkdownDescription returns a markdown description of the plan modifier.
+func (m ensureSelectedFieldsDiff) MarkdownDescription(_ context.Context) string {
+	return "Ensure the order of field paths is consistent"
+}
+
+// PlanModifyList implements the plan modification logic.
+func (m ensureSelectedFieldsDiff) PlanModifyList(ctx context.Context, req planmodifier.ListRequest, resp *planmodifier.ListResponse) {
+	// Do nothing if there is an unknown configuration value
+	if req.ConfigValue.IsUnknown() {
+		return
+	}
+
+	if utils.IsAllStateUnknown(ctx, req.State) {
+		return
+	}
+
+	// Extract the elements from the plan value
+	elements := []types.Object{}
+	for _, elem := range req.PlanValue.Elements() {
+		obj, ok := elem.(types.Object)
+		if !ok {
+			resp.Diagnostics.AddError(
+				"Error modifying list",
+				fmt.Sprintf("Expected object element, got %T", elem),
+			)
+			return
+		}
+
+		_, ok = obj.Attributes()["field_path"]
+		if ok {
+			elements = append(elements, obj)
+		}
+	}
+
+	slices.SortFunc(elements, fieldPathCmp)
+
+	newPlanValue, diags := types.ListValueFrom(ctx, resp.PlanValue.ElementType(ctx), elements)
+	resp.Diagnostics.Append(diags...)
+	if resp.Diagnostics.HasError() {
+		return
+	}
+
+	resp.PlanValue = newPlanValue
+}
+
+// Sort objects by the length of the field path first, then by the field path lexicographically.
+func fieldPathCmp(a, b types.Object) int {
+	aLen := len(a.Attributes()["field_path"].String())
+	bLen := len(b.Attributes()["field_path"].String())
+
+	if aLen < bLen {
+		return -1
+	}
+
+	if aLen == bLen {
+		aFieldPath := a.Attributes()["field_path"].String()
+		bFieldPath := b.Attributes()["field_path"].String()
+
+		if aFieldPath < bFieldPath {
+			return -1
+		}
+
+		if aFieldPath == bFieldPath {
+			return 0
+		}
+	}
+
+	return 1
+}

internal/provider/connection_resource.go

@@ -480,6 +480,7 @@ func (r *ConnectionResource) Schema(ctx context.Context, req resource.SchemaRequ
 									Computed: true,
 									Optional: true,
 									PlanModifiers: []planmodifier.List{
+										speakeasy_listplanmodifier.EnsureSelectedFieldsDiff(),
 										speakeasy_listplanmodifier.SuppressDiff(speakeasy_listplanmodifier.ExplicitSuppress),
 									},
 									NestedObject: schema.NestedAttributeObject{