Function generateApiMethod

java/scripts/codegen/java.ts:1678–1749

* Generate the Java source for a single method in a wrapper API class. * Returns the Java source lines and whether an ObjectMapper is required.

(
    key: string,
    method: RpcMethodNode,
    isSession: boolean,
    sessionIdExpr: string
)

 * Returns the Java source lines and whether an ObjectMapper is required.
 */
function generateApiMethod(
    key: string,
    method: RpcMethodNode,
    isSession: boolean,
    sessionIdExpr: string
): { lines: string[]; needsMapper: boolean; needsExperimentalImport: boolean } {
    const resultClass = wrapperResultClassName(method);
    const paramsClass = wrapperParamsClassName(method);
    const hasSessionId = methodHasSessionId(method);
    const hasExtraParams = paramsClass !== null;
    let needsMapper = false;

    const lines: string[] = [];

    // Javadoc
    const description = (method.params as JSONSchema7 | null)?.description
        ?? (method.result as JSONSchema7 | null)?.description
        ?? `Invokes {@code ${method.rpcMethod}}.`;
    lines.push(`    /**`);
    lines.push(`     * ${description}`);
    if (isSession && hasExtraParams && hasSessionId) {
        lines.push(`     * <p>`);
        lines.push(`     * Note: the {@code sessionId} field in the params record is overridden`);
        lines.push(`     * by the session-scoped wrapper; any value provided is ignored.`);
    }
    if (method.stability === "experimental") {
        lines.push(`     *`);
        lines.push(`     * @apiNote This method is experimental and may change in a future version.`);
    }
    lines.push(`     * @since 1.0.0`);
    lines.push(`     */`);
    if (method.deprecated) {
        lines.push(`    @Deprecated`);
    }
    if (method.stability === "experimental") {
        lines.push(`    @CopilotExperimental`);
    }

    // Signature
    if (hasExtraParams) {
        lines.push(`    public CompletableFuture<${resultClass}> ${key}(${paramsClass} params) {`);
    } else {
        lines.push(`    public CompletableFuture<${resultClass}> ${key}() {`);
    }

    // Body
    if (isSession) {
        if (hasExtraParams) {
            // Merge sessionId into the params using Jackson ObjectNode
            needsMapper = true;
            lines.push(`        com.fasterxml.jackson.databind.node.ObjectNode _p = MAPPER.valueToTree(params);`);
            lines.push(`        _p.put("sessionId", ${sessionIdExpr});`);
            lines.push(`        return caller.invoke("${method.rpcMethod}", _p, ${wrapperResultTypeExpression(resultClass)});`);
        } else if (hasSessionId) {
            lines.push(`        return caller.invoke("${method.rpcMethod}", java.util.Map.of("sessionId", ${sessionIdExpr}), ${wrapperResultTypeExpression(resultClass)});`);
        } else {
            lines.push(`        return caller.invoke("${method.rpcMethod}", java.util.Map.of(), ${wrapperResultTypeExpression(resultClass)});`);
        }