Function writeNumericArg

lib/internal/ffi-shared-buffer.js:122–157

(view, info, offset, arg, index)

// Validation and error messages must mirror `ToFFIArgument` in
// `src/ffi/types.cc`.
function writeNumericArg(view, info, offset, arg, index) {
  const kind = info.kind;
  if (kind === 'int') {
    if (typeof arg !== 'number' || !NumberIsInteger(arg) ||
        arg < info.min || arg > info.max) {
      throwFFIArgError(`Argument ${index} must be ${info.label}`);
    }
    info.set(view, offset, arg, true);
    return;
  }
  if (kind === 'i64') {
    if (typeof arg !== 'bigint' || arg < I64_MIN || arg > I64_MAX) {
      throwFFIArgError(`Argument ${index} must be ${info.label}`);
    }
    sI64(view, offset, arg, true);
    return;
  }
  if (kind === 'u64') {
    if (typeof arg !== 'bigint' || arg < 0n || arg > U64_MAX) {
      throwFFIArgError(`Argument ${index} must be ${info.label}`);
    }
    sU64(view, offset, arg, true);
    return;
  }
  if (kind === 'float') {
    if (typeof arg !== 'number') {
      throwFFIArgError(`Argument ${index} must be ${info.label}`);
    }
    info.set(view, offset, arg, true);
    return;
  }

  // Unreachable: caller filters out non-numeric kinds.
  /* c8 ignore next */
  assert.fail(`FFI: writeNumericArg reached with unexpected kind="${kind}"`);
}

// Returns true on fast-path success, false when the caller must fall back
// to the slow path (strings, Buffers, ArrayBuffers, ArrayBufferViews).