message: Fix Hover.is
diff: @@ -1598,7 +1598,7 @@ export namespace Hover {
  */
  export function is(value: any): value is Hover {
  let candidate = value as Hover;
  - return Is.objectLiteral(candidate) && (
  + return candidate && Is.objectLiteral(candidate) && (
  MarkupContent.is(candidate.contents) ||
  MarkedString.is(candidate.contents) ||
  Is.typedArray(candidate.contents, MarkedString.is)
  @@ -2098,7 +2098,11 @@ export namespace CodeActionKind {
  */
  export interface CodeActionContext {
  /**
  - * An array of diagnostics.
  + * An array of diagnostics known on the client side overlapping the range provided to the
  + * `textDocument/codeAction` request. They are provied so that the server knows which
  + * errors are currently presented to the user for the given range. There is no guarantee
  + * that these accurately reflect the error state of the resource. The primary parameter
  + * to compute code actions is the provided range.
  */
  diagnostics: Diagnostic[];
  