Function emitRustStruct

scripts/codegen/rust.ts:861–963

(
	typeName: string,
	schema: JSONSchema7,
	ctx: RustCodegenCtx,
	description?: string,
)

// ── Struct emission ─────────────────────────────────────────────────────────

function emitRustStruct(
	typeName: string,
	schema: JSONSchema7,
	ctx: RustCodegenCtx,
	description?: string,
): void {
	if (ctx.generatedNames.has(typeName)) return;
	ctx.generatedNames.add(typeName);

	const required = new Set(schema.required || []);
	const lines: string[] = [];
	const desc = description || schema.description;
	if (desc) {
		for (const line of desc.split(/\r?\n/)) {
			lines.push(`/// ${line}`);
		}
	}
	pushRustExperimentalDocs(lines, isSchemaExperimental(schema) || ctx.experimentalTypeNames.has(typeName));
	if (isSchemaDeprecated(schema)) {
		lines.push(...rustDeprecatedAttributes());
	}
	const structVis = isSchemaInternal(schema) ? "pub(crate)" : "pub";

	// Resolve field types up-front so we can decide whether `Default` can be
	// derived. A required field whose bare type is non-default-able (e.g. an
	// untagged enum, or another struct that already opted out) blocks the
	// derive and propagates the opt-out to this struct.
	interface FieldInfo {
		propName: string;
		prop: JSONSchema7;
		isReq: boolean;
		rustField: string;
		rustType: string;
	}
	const fields: FieldInfo[] = [];
	for (const [propName, propSchema] of Object.entries(
		schema.properties || {},
	)) {
		if (typeof propSchema !== "object") continue;
		const prop = propSchema as JSONSchema7;
		const isReq = required.has(propName);
		const rustField = safeRustFieldName(propName);
		const rustType = resolveRustType(prop, typeName, propName, isReq, ctx);
		fields.push({ propName, prop, isReq, rustField, rustType });
	}

	const blocksDefault = fields.some(
		(f) => f.isReq && ctx.nonDefaultableTypes.has(f.rustType),
	);
	if (blocksDefault) {
		ctx.nonDefaultableTypes.add(typeName);
		lines.push("#[derive(Debug, Clone, Serialize, Deserialize)]");
	} else {
		lines.push("#[derive(Debug, Clone, Default, Serialize, Deserialize)]");
	}
	lines.push(`#[serde(rename_all = "camelCase")]`);
	lines.push(`${structVis} struct ${typeName} {`);