new: Support property_format TS option.

CHANGELOG.md

@@ -99,6 +99,7 @@ if using the macros, otherwise you'll need to update your schema implementations
 
 #### 🚀 Updates
 
+- Added a `property_format` option to the TypeScript renderer.
 - Added a `tracing` feature flag, that will wrap generated config methods with
   `#[tracing::instrument]`.
 - Updated the macro generated code to use `Box` in many places to reduce the size of enums and

book/src/schema/generator/typescript.md

@@ -116,6 +116,38 @@ export type User = {
 };
 ```
 
+### Properties format
+
+Properties within a struct can be rendered as either optional or required in TypeScript, depending
+on usage. The default format for all properties can be customized with the `property_format` option
+and the
+[`PropertyFormat`](https://docs.rs/schematic/latest/schematic/schema/typescript/enum.PropertyFormat.html)
+enum. By default all properties are required.
+
+```rust
+TypeScriptOptions {
+	// ...
+	property_format: PropertyFormat::Required,
+}
+```
+
+```ts
+// Default / required
+export interface User {
+	name: string;
+}
+
+// Optional
+export interface User {
+	name?: string;
+}
+
+// Optional with undefined union
+export interface User {
+	name?: string | undefined;
+}
+```
+
 ### Type references
 
 In the context of this renderer, a type reference is simply a reference to another type by its name,

crates/schematic/src/schema/renderers/typescript.rs

@@ -25,6 +25,18 @@ pub enum ObjectFormat {
     Type,
 }
 
+/// Format of TypeScript object properties.
+#[derive(Default)]
+pub enum PropertyFormat {
+    /// Required: `prop: value`
+    #[default]
+    Required,
+    /// Optional: `prop?: value`
+    Optional,
+    /// Optional with undefined: `prop?: value | undefined`
+    OptionalUndefined,
+}
+
 /// Options to control the rendered TypeScript output.
 #[derive(Default)]
 pub struct TypeScriptOptions {
@@ -49,6 +61,9 @@ pub struct TypeScriptOptions {
 
     /// Format to render objects, either an `interface` or `type`.
     pub object_format: ObjectFormat,
+
+    /// Format to render object properties as.
+    pub property_format: PropertyFormat,
 }
 
 /// Renders TypeScript types from a schema.
@@ -366,14 +381,26 @@ impl<'gen> SchemaRenderer<'gen, String> for TypeScriptRenderer<'gen> {
 
             let mut row = format!("{}{}", indent, name);
 
-            if field.optional {
+            if field.optional
+                || matches!(
+                    self.options.property_format,
+                    PropertyFormat::Optional | PropertyFormat::OptionalUndefined
+                )
+            {
                 row.push_str("?: ");
             } else {
                 row.push_str(": ");
             }
 
             row.push_str(&self.render_schema(field)?);
 
+            if matches!(
+                self.options.property_format,
+                PropertyFormat::OptionalUndefined
+            ) {
+                row.push_str(" | undefined");
+            }
+
             if matches!(self.options.object_format, ObjectFormat::Interface) {
                 row.push(';');
             } else {

crates/schematic/tests/generator_test.rs

@@ -356,6 +356,22 @@ mod typescript {
         }));
     }
 
+    #[test]
+    fn props_optional() {
+        assert_snapshot!(generate(TypeScriptOptions {
+            property_format: PropertyFormat::Optional,
+            ..TypeScriptOptions::default()
+        }));
+    }
+
+    #[test]
+    fn props_optional_undefined() {
+        assert_snapshot!(generate(TypeScriptOptions {
+            property_format: PropertyFormat::OptionalUndefined,
+            ..TypeScriptOptions::default()
+        }));
+    }
+
     #[test]
     fn exclude_refs() {
         assert_snapshot!(generate(TypeScriptOptions {

crates/schematic/tests/snapshots/generator_test__typescript__props_optional.snap

@@ -0,0 +1,57 @@
+---
+source: crates/schematic/tests/generator_test.rs
+expression: "generate(TypeScriptOptions {\n        property_format: PropertyFormat::Optional,\n        ..TypeScriptOptions::default()\n    })"
+---
+// Automatically generated by schematic. DO NOT MODIFY!
+
+/* eslint-disable */
+
+export type BasicEnum = 'foo' | 'bar' | 'baz';
+
+export type FallbackEnum = 'foo' | 'bar' | 'baz' | string;
+
+export interface AnotherConfig {
+	/**
+	 * An optional enum.
+	 *
+	 * @default 'foo'
+	 */
+	enums?: BasicEnum | null;
+	/** An optional string. */
+	opt?: string | null;
+}
+
+export interface GenConfig {
+	boolean?: boolean;
+	date?: string;
+	datetime?: string;
+	decimal?: string;
+	/**
+	 * This is a list of `enumerable` values.
+	 *
+	 * @default 'foo'
+	 */
+	enums?: BasicEnum;
+	/** @default 'foo' */
+	fallbackEnum?: FallbackEnum;
+	float32?: number;
+	float64?: number;
+	indexmap?: Record<string, string>;
+	indexset?: string[] | null;
+	jsonValue?: unknown;
+	map?: Record<string, number>;
+	/** **Nested** field. */
+	nested?: AnotherConfig;
+	number?: number;
+	path?: string;
+	relPath?: string;
+	string?: string;
+	time?: string;
+	tomlValue?: unknown | null;
+	url?: string | null;
+	/** This is a list of strings. */
+	vector?: string[];
+	version?: string | null;
+	versionReq?: string;
+	yamlValue?: unknown;
+}

crates/schematic/tests/snapshots/generator_test__typescript__props_optional_undefined.snap

@@ -0,0 +1,57 @@
+---
+source: crates/schematic/tests/generator_test.rs
+expression: "generate(TypeScriptOptions {\n        property_format: PropertyFormat::OptionalUndefined,\n        ..TypeScriptOptions::default()\n    })"
+---
+// Automatically generated by schematic. DO NOT MODIFY!
+
+/* eslint-disable */
+
+export type BasicEnum = 'foo' | 'bar' | 'baz';
+
+export type FallbackEnum = 'foo' | 'bar' | 'baz' | string;
+
+export interface AnotherConfig {
+	/**
+	 * An optional enum.
+	 *
+	 * @default 'foo'
+	 */
+	enums?: BasicEnum | null | undefined;
+	/** An optional string. */
+	opt?: string | null | undefined;
+}
+
+export interface GenConfig {
+	boolean?: boolean | undefined;
+	date?: string | undefined;
+	datetime?: string | undefined;
+	decimal?: string | undefined;
+	/**
+	 * This is a list of `enumerable` values.
+	 *
+	 * @default 'foo'
+	 */
+	enums?: BasicEnum | undefined;
+	/** @default 'foo' */
+	fallbackEnum?: FallbackEnum | undefined;
+	float32?: number | undefined;
+	float64?: number | undefined;
+	indexmap?: Record<string, string> | undefined;
+	indexset?: string[] | null | undefined;
+	jsonValue?: unknown | undefined;
+	map?: Record<string, number> | undefined;
+	/** **Nested** field. */
+	nested?: AnotherConfig | undefined;
+	number?: number | undefined;
+	path?: string | undefined;
+	relPath?: string | undefined;
+	string?: string | undefined;
+	time?: string | undefined;
+	tomlValue?: unknown | null | undefined;
+	url?: string | null | undefined;
+	/** This is a list of strings. */
+	vector?: string[] | undefined;
+	version?: string | null | undefined;
+	versionReq?: string | undefined;
+	yamlValue?: unknown | undefined;
+}