List<T> -> Option<List<T>>, no more List<T> defaults

CHANGELOG.md

@@ -80,6 +80,8 @@ should include the dependency `stripe_webhook` and import from that crate instea
 - `Deleted<>` objects (such `Deleted<Account>`) no longer expose a boolean `deleted`. This was always `true` and only
 used internally as a discriminant when deserializing. The generic type `Deleted` has been removed and replaced by 
 generated types such as `DeletedAccount`, which sometimes contain additional fields.
+- Optional `List<T>` no longer deserialized with `serde(default)`, the type has been changed `List<T>` -> `Option<List<T>>`. The default
+implementation of `List<T>` produced data not upholding the `List<T>` invariant of having a meaningful `url`.
 - Types used only for requests now use borrowed types more consistently (and more often). For example, previously the top-level
 `CreateCustomer.description` expected `Option<&str>`, but `CreateCustomerShipping.phone` expected `Option<String>`. Now
 both expect `Option<&str>`. In general, the following changes are made to request parameters that required owned data:

examples/endpoints/src/checkout.rs

@@ -75,16 +75,17 @@ pub async fn run_checkout_session_example(client: &stripe::Client) -> Result<(),
         params.send(client).await?
     };
 
+    let created_item = &checkout_session.line_items.expect("line items were created").data[0];
     println!(
         "created a {} checkout session for {} {:?} for {} {} at {}",
         checkout_session.payment_status,
-        checkout_session.line_items.data[0].quantity.unwrap(),
-        match &checkout_session.line_items.data[0].price.as_ref().unwrap().product {
+        created_item.quantity.unwrap(),
+        match &created_item.price.as_ref().unwrap().product {
             Expandable::Object(p) => &p.name,
             _ => panic!("product not found"),
         },
         checkout_session.amount_subtotal.unwrap() / 100,
-        checkout_session.line_items.data[0].price.as_ref().unwrap().currency,
+        created_item.price.as_ref().unwrap().currency,
         checkout_session.url.unwrap()
     );
     Ok(())

generated/stripe_checkout/src/checkout_session/mod.rs

@@ -71,8 +71,8 @@ pub struct CheckoutSession {
     /// Details on the state of invoice creation for the Checkout Session.
     pub invoice_creation: Option<stripe_checkout::PaymentPagesCheckoutSessionInvoiceCreation>,
     /// The line items purchased by the customer.
-    #[serde(default)]
-    pub line_items: stripe_types::List<stripe_shared::CheckoutSessionItem>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub line_items: Option<stripe_types::List<stripe_shared::CheckoutSessionItem>>,
     /// Has the value `true` if the object exists in live mode or the value `false` if the object exists in test mode.
     pub livemode: bool,
     /// The IETF language tag of the locale Checkout is displayed in.

generated/stripe_misc/src/tax_calculation/mod.rs

@@ -19,7 +19,7 @@ pub struct TaxCalculation {
     /// Unique identifier for the calculation.
     pub id: Option<stripe_misc::tax_calculation::TaxCalculationId>,
     /// The list of items the customer is purchasing.
-    pub line_items: stripe_types::List<stripe_misc::TaxCalculationLineItem>,
+    pub line_items: Option<stripe_types::List<stripe_misc::TaxCalculationLineItem>>,
     /// Has the value `true` if the object exists in live mode or the value `false` if the object exists in test mode.
     pub livemode: bool,
     /// The shipping cost details for the calculation.

generated/stripe_misc/src/tax_transaction/mod.rs

@@ -19,7 +19,7 @@ pub struct TaxTransaction {
     /// Unique identifier for the transaction.
     pub id: stripe_misc::tax_transaction::TaxTransactionId,
     /// The tax collected or refunded, by line item.
-    pub line_items: stripe_types::List<stripe_misc::TaxTransactionLineItem>,
+    pub line_items: Option<stripe_types::List<stripe_misc::TaxTransactionLineItem>>,
     /// Has the value `true` if the object exists in live mode or the value `false` if the object exists in test mode.
     pub livemode: bool,
     /// Set of [key-value pairs](https://stripe.com/docs/api/metadata) that you can attach to an object.

generated/stripe_shared/src/account/mod.rs

@@ -46,8 +46,8 @@ pub struct Account {
     #[serde(skip_serializing_if = "Option::is_none")]
     pub email: Option<String>,
     /// External accounts (bank accounts and debit cards) currently attached to this account.
-    #[serde(default)]
-    pub external_accounts: stripe_types::List<stripe_shared::ExternalAccount>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub external_accounts: Option<stripe_types::List<stripe_shared::ExternalAccount>>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub future_requirements: Option<stripe_shared::AccountFutureRequirements>,
     /// Unique identifier for the object.

generated/stripe_shared/src/charge/mod.rs

@@ -109,7 +109,7 @@ pub struct Charge {
     /// If the charge is only partially refunded, this attribute will still be false.
     pub refunded: bool,
     /// A list of refunds that have been applied to the charge.
-    pub refunds: stripe_types::List<stripe_shared::Refund>,
+    pub refunds: Option<stripe_types::List<stripe_shared::Refund>>,
     /// ID of the review associated with this charge if one exists.
     pub review: Option<stripe_types::Expandable<stripe_shared::Review>>,
     /// Shipping information for the charge.

generated/stripe_shared/src/customer/mod.rs

@@ -88,11 +88,11 @@ pub struct Customer {
     /// Appears on invoices emailed to this customer.
     pub shipping: Option<stripe_shared::Shipping>,
     /// The customer's payment sources, if any.
-    #[serde(default)]
-    pub sources: stripe_types::List<stripe_shared::PaymentSource>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub sources: Option<stripe_types::List<stripe_shared::PaymentSource>>,
     /// The customer's current subscriptions, if any.
-    #[serde(default)]
-    pub subscriptions: stripe_types::List<stripe_shared::Subscription>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub subscriptions: Option<stripe_types::List<stripe_shared::Subscription>>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub tax: Option<stripe_shared::CustomerTax>,
     /// Describes the customer's tax exemption status, which is `none`, `exempt`, or `reverse`.
@@ -101,8 +101,8 @@ pub struct Customer {
     #[serde(skip_serializing_if = "Option::is_none")]
     pub tax_exempt: Option<CustomerTaxExempt>,
     /// The customer's tax IDs.
-    #[serde(default)]
-    pub tax_ids: stripe_types::List<stripe_shared::TaxId>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub tax_ids: Option<stripe_types::List<stripe_shared::TaxId>>,
     /// ID of the test clock that this customer belongs to.
     #[serde(skip_serializing_if = "Option::is_none")]
     pub test_clock: Option<stripe_types::Expandable<stripe_shared::TestHelpersTestClock>>,

generated/stripe_shared/src/file/mod.rs

@@ -15,8 +15,8 @@ pub struct File {
     /// Unique identifier for the object.
     pub id: stripe_shared::file::FileId,
     /// A list of [file links](https://stripe.com/docs/api#file_links) that point at this file.
-    #[serde(default)]
-    pub links: stripe_types::List<stripe_shared::FileLink>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub links: Option<stripe_types::List<stripe_shared::FileLink>>,
     /// The [purpose](https://stripe.com/docs/file-upload#uploading-a-file) of the uploaded file.
     pub purpose: FilePurpose,
     /// The size of the file object in bytes.

generated/stripe_shared/src/payment_link/mod.rs

@@ -38,8 +38,8 @@ pub struct PaymentLink {
     /// Configuration for creating invoice for payment mode payment links.
     pub invoice_creation: Option<stripe_shared::PaymentLinksResourceInvoiceCreation>,
     /// The line items representing what is being sold.
-    #[serde(default)]
-    pub line_items: stripe_types::List<stripe_shared::CheckoutSessionItem>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub line_items: Option<stripe_types::List<stripe_shared::CheckoutSessionItem>>,
     /// Has the value `true` if the object exists in live mode or the value `false` if the object exists in test mode.
     pub livemode: bool,
     /// Set of [key-value pairs](https://stripe.com/docs/api/metadata) that you can attach to an object.

generated/stripe_shared/src/quote/mod.rs

@@ -66,8 +66,8 @@ pub struct Quote {
     /// All invoices will be billed using the specified settings.
     pub invoice_settings: Option<stripe_shared::InvoiceSettingQuoteSetting>,
     /// A list of items the customer is being quoted for.
-    #[serde(default)]
-    pub line_items: stripe_types::List<stripe_shared::CheckoutSessionItem>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub line_items: Option<stripe_types::List<stripe_shared::CheckoutSessionItem>>,
     /// Has the value `true` if the object exists in live mode or the value `false` if the object exists in test mode.
     pub livemode: bool,
     /// Set of [key-value pairs](https://stripe.com/docs/api/metadata) that you can attach to an object.

generated/stripe_shared/src/quotes_resource_upfront/mod.rs

@@ -7,7 +7,7 @@ pub struct QuotesResourceUpfront {
     /// The line items that will appear on the next invoice after this quote is accepted.
     ///
     /// This does not include pending invoice items that exist on the customer but may still be included in the next invoice.
-    #[serde(default)]
-    pub line_items: stripe_types::List<stripe_shared::CheckoutSessionItem>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub line_items: Option<stripe_types::List<stripe_shared::CheckoutSessionItem>>,
     pub total_details: stripe_shared::QuotesResourceTotalDetails,
 }

generated/stripe_treasury/src/treasury_transaction/mod.rs

@@ -19,7 +19,7 @@ pub struct TreasuryTransaction {
     /// A list of TransactionEntries that are part of this Transaction.
     ///
     /// This cannot be expanded in any list endpoints.
-    pub entries: stripe_types::List<stripe_treasury::TreasuryTransactionEntry>,
+    pub entries: Option<stripe_types::List<stripe_treasury::TreasuryTransactionEntry>>,
     /// The FinancialAccount associated with this object.
     pub financial_account: String,
     /// ID of the flow that created the Transaction.

openapi/src/rust_object.rs

@@ -221,23 +221,6 @@ impl StructField {
     }
 }
 
-/// Specifications for a `serde(default = ...)` attribute
-#[derive(Copy, Clone, Debug, Eq, PartialEq, Default, Hash)]
-pub enum DeserDefault {
-    /// Just `serde(default)`
-    #[default]
-    Default,
-}
-
-impl DeserDefault {
-    /// The corresponding `serde` attribute
-    pub fn to_serde_attr(self) -> &'static str {
-        match self {
-            Self::Default => "#[serde(default)]",
-        }
-    }
-}
-
 pub struct ObjectRef {
     pub path: ComponentPath,
     pub feature_gate: Option<String>,

openapi/src/rust_type.rs

@@ -1,7 +1,7 @@
 use std::fmt::{Debug, Display, Formatter};
 
 use crate::components::Components;
-use crate::rust_object::{DeserDefault, ObjectMetadata, RustObject};
+use crate::rust_object::{ObjectMetadata, RustObject};
 use crate::types::{ComponentPath, RustIdent};
 use crate::visitor::{Visit, VisitMut};
 
@@ -202,7 +202,7 @@ impl RustType {
 
     pub fn into_nullable(self) -> Self {
         match self {
-            Self::Container(Container::List(_)) | Self::Container(Container::Option(_)) => self,
+            Self::Container(Container::Option(_)) => self,
             _ => Self::option(self),
         }
     }
@@ -248,15 +248,6 @@ impl RustType {
         self.as_object().map(|r| r.0)
     }
 
-    pub fn deser_default(&self) -> Option<DeserDefault> {
-        match self {
-            Self::Simple(SimpleType::Bool)
-            | Self::Container(Container::Vec(_))
-            | Self::Container(Container::List(_)) => Some(DeserDefault::Default),
-            _ => None,
-        }
-    }
-
     pub fn visit<'a, T: Visit<'a>>(&'a self, visitor: &mut T) {
         use RustType::*;
         match self {

openapi/src/templates/structs.rs

@@ -90,9 +90,6 @@ impl<'a> ObjectWriter<'a> {
             if let Some(skip_ser) = field.rust_type.skip_serializing() {
                 let _ = writeln!(out, r#"#[serde(skip_serializing_if = "{skip_ser}")]"#);
             }
-            if let Some(default) = field.rust_type.deser_default() {
-                let _ = writeln!(out, "{}", default.to_serde_attr());
-            }
         }
 
         let printable = self.get_printable(&field.rust_type);

stripe_types/src/pagination.rs

@@ -118,12 +118,6 @@ pub struct List<T> {
     pub url: String,
 }
 
-impl<T> Default for List<T> {
-    fn default() -> Self {
-        List { data: Vec::new(), has_more: false, total_count: None, url: String::new() }
-    }
-}
-
 impl<T: Clone> Clone for List<T> {
     fn clone(&self) -> Self {
         List {

tests/tests/it/blocking/charge.rs

@@ -10,6 +10,6 @@ fn is_charge_retrievable() {
         assert_eq!(charge.id, "ch_123");
         assert!(charge.customer.is_none());
         assert!(charge.invoice.is_none());
-        assert_eq!(charge.refunds.data.len(), 1);
+        assert_eq!(charge.refunds.unwrap().data.len(), 1);
     });
 }

tests/tests/it/main.rs

@@ -8,4 +8,7 @@ mod price;
 mod async_tests;
 #[cfg(feature = "blocking")]
 mod blocking;
+// NB: pagination utils ideally could be used for blocking tests as well, but tricky because the `MockServer` is async
+// and the blocking client unconditionally creates its own runtime already
+#[cfg(feature = "async")]
 mod pagination_utils;