use wasm_encoder::{
    CodeSection, ExportKind, ExportSection, Function, FunctionSection, Instruction,
    Module, TypeSection, ValType,
};

let mut module = Module::new();

// Encode the type section.
let mut types = TypeSection::new();
let params = vec![ValType::I32, ValType::I32];
let results = vec![ValType::I32];
types.function(params, results);
module.section(&types);

// Encode the function section.
let mut functions = FunctionSection::new();
let type_index = 0;
functions.function(type_index);
module.section(&functions);

// Encode the export section.
let mut exports = ExportSection::new();
exports.export("f", ExportKind::Func, 0);
module.section(&exports);

// Encode the code section.
let mut codes = CodeSection::new();
let locals = vec![];
let mut f = Function::new(locals);
f.instruction(&Instruction::LocalGet(0));
f.instruction(&Instruction::LocalGet(1));
f.instruction(&Instruction::I32Add);
f.instruction(&Instruction::End);
codes.function(&f);
module.section(&codes);

// Extract the encoded Wasm bytes for this module.
let wasm_bytes = module.finish();

// We generated a valid Wasm module!
assert!(wasmparser::validate(&wasm_bytes).is_ok());